reproduction

Oh, the many things estrogens can do...in males

dr. dolittle — Mon, 19 Jun 2017 14:46:15 +0000

Oh, the many things estrogens can do...in males

Estradiol is the major estrogen in humans. Chemical structure by NEUROtiker (Own work) [Public domain], via Wikimedia Commons

I came across an article published in Physiological Reviews with a title so irresistible (Estrogens in Male Physiology), I just had to read it. While I knew that males have estrogen, this article impressed me with the numerous things estrogens are associated with, some of which were new to me and highlight how important estrogens are to male reproductive and non-reproductive physiology.

As early as the 1930's researchers discovered that stallions had high levels of estrogen in their urine. Since then, males from many species have been found to produce estrogen and receptors for estrogen can be found throughout development and adulthood. Researchers have more recently come to discover that estrogen plays a role in the normal physiology of both reproductive and nonreproductive organs in males. In females, estrogens are mainly produced by the ovaries. In contrast, males can produce estrogens from androgens through the action of an enzyme called aromatase. This conversion process happens in the testes, fat, brain, skin and bone. Studies have shown that in males, estrogen regulates bone growth, glucose and fat metabolism, in addition to playing an important role in fertility. In fact, low circulating estrogen concentrations are a better predictor than testosterone of osteoporosis and fracture risk in elderly men. Additionally, estrogens may help protect the brain after a traumatic brain injury (TBI) or stroke and may offer protection from the development of schizophrenia. Estrogens are also associated with helping to regulate immunity, bladder function, and wound healing.

Although more studies are needed to fully understand the myriad of functions estrogens play in males, these studies may pave the way to potential new therapies for estrogen-related diseases in both men and women.

Source:

PS Cooke, MK Nanjappa, C Ko, GS Prins, RA Hess. Estrogens in Male Physiology. Physiological Reviews. Published 24 May 2017 Vol. 97 no. 3, 995-1043. DOI: 10.1152/physrev.00018.2016

dr. dolittle Mon, 06/19/2017 - 10:46

Tags

Life Science

estrogen

growth

physiology

reproduction

Do gay men tend to have more estrogen than straight men?

No, they don't... however, they do react differently to them than do straight men, as do androphilic MTF transsexuals, but NOT gynephilic transsexuals:

https://sillyolme.wordpress.com/2015/12/28/brain-power/

First known case of zebra shark switching to asexual reproduction

dr. dolittle — Tue, 17 Jan 2017 23:50:29 +0000

First known case of zebra shark switching to asexual reproduction

Photo of one of Leonie's hatchlings from Tourism and Events Queensland.

The story begins in 1999 when Leonie, a zebra shark (aka a leopard shark in Australia), was captured from the wild. In 2006 she was transferred to Reef HQ Aquarium in Queensland, Australia where she met her mate. By 2008, she had started laying eggs and the pair had multiple litters of offspring through sexual reproduction. After her mate was removed from the tank to prevent further breeding, she has shared the tank with one of her offspring, a female named Lolly who, since reaching sexual maturity herself, has never lived with a male zebra shark. Amazingly, both Leonie and Lolly have produced five hatchlings. Laying inviable eggs is one thing (think chickens), but laying viable eggs means these females were undergoing asexual reproduction as confirmed by genetic tests which showed the hatchlings were homozygous. While asexual reproduction in itself is not unusual, switching from sexual to asexual reproduction in Leonie's case (and most mammals) is quite unusual. Only time will tell how well these homozygous zebra shark offspring fare.

Source:

The Guardian

dr. dolittle Tue, 01/17/2017 - 18:50

Tags

"Leonie’s case (and most other mammals)..."
Sharks aren't mammals.

Thank you for catching that typo. Indeed sharks are not mammals. I meant to say "and most mammals".

Nice article.

Nice. I want a baby shark.

I would add that in mammals, natural asexual reproduction has never been observed, and it is considered that, maybe with the exception of monotremes, it's impossible.

Nice article.I want a baby shark.
http://www.192-168-0-1.link

Why orcas go through menopause

dr. dolittle — Fri, 13 Jan 2017 17:58:30 +0000

Why orcas go through menopause

Image of an orca and her calf from Wikimedia Commons

Orcas are one of only three species of mammals that go through menopause, including humans of course. A new study published in Current Biology may have discovered why this happens in killer whales.

Examination of 43 years worth of data collected by the Center for Whale Research and Fisheries and Oceans Canada, revealed a remarkable finding about the costs of reproduction in orcas. Older mothers tend to spend more time taking care of the family, so to speak, by making sure her offspring know where or when to find food. While this cooperative foraging behavior helps improve survival of the mother's family, further offspring from the mother are 1.7 times more likely to die than her daughter's offspring. This reproductive competition (or conflict) is thought to be a reason why the whales (and perhaps humans) evolved to go through menopause.

Source:

DP Croft, RA Johnston, S Ellis, S Nattrass, DW Franks, LJN Brent, S Mazzi, KC Balcomb, JKB Ford, MA Cant. Reproductive Conflict and the Evolution of Menopause in Killer. Current Biology. 27: 1-7, 2017. DOI: 10.1016/j.cub.2016.12.015

dr. dolittle Fri, 01/13/2017 - 12:58

Tags

The cost of male pheromones

dr. dolittle — Fri, 16 Sep 2016 12:39:31 +0000

The cost of male pheromones

Video of C. elegans from Wikipedia. https://upload.wikimedia.org/wikipedia/commons/b/be/CrawlingCelegans.gif

A new study conducted by researchers at Northwestern University examined the costs of reproduction in roundworms, otherwise known as C. elegans. They discovered that male roundworms can send two kinds of pheromones that prime females for reproduction. One type of pheromone they studied sparks the onset of puberty in young female worms while the other prolongs fertility in aging females. The problem is that these changes come at a cost as it shortens the lifespan of female roundworms.

According to the study authors, a similar effect has been seen in mammals where a pheromone can change when females become sexually mature.

Since this effect appears common to roundworms and mammals, these findings raise the possibility that something similar might happen with humans. Thus the hope is to apply these findings to humans in an effort to prolong fertility...although I am not sure women would seek out this treatment if it increased aging.

Source:

Aprison EZ, Ruvinsky I. Sexually antagonistic male signals manipulate germline and soma of C. elegans hermaphrodites. Current Biology, 2016 DOI: 10.1016/j.cub.2016.08.024

dr. dolittle Fri, 09/16/2016 - 08:39

Tags

The mystery of the orgasm

pharyngula — Tue, 02 Aug 2016 12:06:57 +0000

The mystery of the orgasm

Perhaps we need to think more about human psychology. There's an interesting phenomenon that goes on all the time when people read about evolution: they shoehorn the observations into some functional purpose. There's just something so satisfying to our minds to be able to say "that thing exists for this particular reason", and we find it frustrating to say, "there is no reason for it, it's just chance and circumstance". It shouldn't be so, but our minds just try to fit everything into that particular mold.

Now watch: some people -- maybe even you -- are going to now try and develop an adaptive scenario for why having brains that work that way is a good thing. We try to build a teleological framework around everything, and so it must have a purpose that is being fulfilled, and we rarely stop to think about whether it may be actually limiting us. Maybe it's not good. Maybe there are other ways that brains can work, and this particular mode of thinking is just a clumsy kludge that resulted from the gradual agglomeration of stuff, mostly unselected, that built up the substrate for human cognition.

A case in point: the female orgasm. There's a new paper out on the subject, and there are lots of articles being written on it, and they generally start out by pointing out that there's something puzzling about the phenomenon: shouldn't it have, you know, a reason for existence? It can't just be, it has to do something useful for women, or reproduction, or pair bonding, or any of dozens of hypotheses that have been proposed.

So NPR finds closure in an explanation.

A pair of scientists have a new hypothesis about why the female orgasm exists: it might have something to do with releasing an egg to be fertilized.

Nope. That's not what the paper says. It says it might be a relic of a historical endocrine function, not that it plays any role in women today.

Carl Zimmer sets up a mystery.

An eye is for seeing, a nose is for smelling. Many aspects of the human body have obvious purposes.

But some defy easy explanation. For biologists, few phenomena are as mysterious as the female orgasm.

I would challenge his analogy: what's so obvious about a nose? Nostrils and an olfactory epithelium, sure -- that does have a clear functional role, and we can see signs of selection in the signal transduction apparatus, but why do we have this bony projection with a knob of cartilage on the end? We think we'd look weird without it (like Voldemort), but there's a wide range of shapes within our species, and related species -- chimps and gorillas, for instance -- don't have much in the way of a nose. It doesn't affect their ability to smell.

(Note: both of those links take you to good summaries. I'm just weirdly conscious of how much we all take adaptive thinking for granted.)

This is the point where I tell you all to go read The Case of the Female Orgasm: Bias in the Science of Evolution by Elisabeth Lloyd, in which she takes apart a collection of adaptive scenarios that simply do not hold up. We ought to face facts: orgasm in women has nothing at all to do with reproduction. It doesn't facilitate transport of semen, it doesn't make them want to lie down horizontally, it doesn't compel them to pair bond with men (since masturbation is a more effective path to orgasm than intercourse, why aren't we arguing that the clitoris is the devil's tool to drive women away from men? Oh, some do.)

Fortunately, this new paper by Pavlicev and Wagner, The Evolutionary Origin of Female Orgasm, doesn't succumb to the fallacy of the spurious adaptive explanation. Instead, it's following a much more useful evolutionary tradition: everything is the way it is because of how it got that way. Every living thing has a line of ancestry, and we inherit with modification the traits of our lineage, and the necessary way to study these traits, since our ancestors aren't generally available for examination, is to take a comparative approach. So they do the evolutionary biology thing and ask what functions female orgasm have in related species, and try to infer an ancestral role in pre-humans.

Here, we note that most hypotheses are seeking an explanation for the presence of female orgasm within the human or primate lineage, whether due to direct or correlated effects of selection. Yet we will argue below that female orgasm, as male orgasm, predate the primate lineage, and the orgasm of human females likely evolved from an ancestral and adaptive trait, which might not have all the characteristics of human orgasm and may also have had a different function. We propose that explanations focusing on primate mating system and behavior thus address the primate-specific (or sometimes human-specific) modifications of a previously existent trait rather than its origin (Amundson, 2008). Our focus here will be the question what that ancestral trait may have been. As the lineage-specific modifications or secondary cooption (“exaptation,” in terms of Gould and Vrba, 1982) can take extreme forms under different, internal, or external selective forces, we therefore do not expect to find in animals a female orgasm as we know it in human, but are rather seeking its homologue in other species.

They also place it in the context of more general theories about the basis of the female orgasm.

The field addressing the role of female orgasm is by no means short of hypotheses. The evolutionary hypotheses align in two groups: one group argues that it is not quite true that female orgasm has no effect on reproductive success (e.g., enabling female choice, bonding, etc.), and the other group argues that it may indeed have no reproductive value in the females, but rather its existence is explained as a correlated effect of another selected trait, or a different developmental stage. For example, one well appreciated among the later hypotheses describes female orgasm as a fortunate consequence of the shared developmental basis of clitoris and penis, and therefore a consequence of reproductive necessity of the male orgasm (by-product hypothesis, Symons, 1979). A critical review of the existing hypotheses has been published in Lloyd (2005) and will not be attempted here.

So the two general hypotheses are that it has an as-yet-undetermined reproductive function (this is so far unsupported by the evidence), or that it is a byproduct of other properties. Pavlicev and Wagner are, I think, adding some other nuances to the story, but their explanation is actually orthogonal to those two explanations.

Pavlicev and Wagner point out that induced ovulation is common in mammals, and is probably a basal trait of the clade, although it has been repeatedly gained and lost. It's an energy saving measure; why should the female spontaneously ovulate all the time, in the absence of an opportunity to become pregnant? We take it for granted -- nuns continue to menstruate, after all -- but many mammals do not ovulate unless they receive an endocrine signal that announces to their ovaries that hey, you're actually mating, this might be a good time to drop an egg for fertilization. In these species, the clitoris seems to be the trigger -- stimulating it induces an endocrine surge that induces ovulation. So the idea is that humans have female orgasms because our distant mammalian ancestors had all this complex hormonal machinery coupling ovulation and coitus, and we've lost the necessity, but the apparatus is still there. We've dismantled the factory, but the remnants still make a fine playground.

Another interesting pattern they see is that when ovulation is uncoupled from clitoral stimulation, there is a tendency for the clitoris to waner farther from the vaginal opening. Induced ovulators tend to have the clitoris positioned right near or even within the vaginal opening, but in animals like humans, it's quite far away and is poorly stimulated by vaginal thrusting. This may be another of those byproducts: the opening of the urethra happens to be between the vagina and the clitoris, so the increasing separation of the clitoris and vagina may be a consequence of increasing the separation of the urethra and vagina.

I do have some slight reservations about the paper, though. One is that the explanation is insufficient. Here's their diagram of the phylogenetic distribution of induced ovulation.

Phylogenetic distribution of (A) modes of ovulation, (B) the presence of the urogenital sinus (UGS; in basal species: cloaca), and (C) the position of clitoris relative to the vaginal orifice (in, border, out). Note the phylogenetic correlation between spontaneous ovulation with the reduction of the urogenital sinus, and the external position of the clitoris. This correlation is suggestive of an ancestral role of clitoral stimulation for the initiation of pregnancy in induced ovulators and the loss of this function in spontaneous ovulators.

Note that our lineage seems to have lost this property at the separation of rodents and primates! One estimate is that this divergence occurred about 96 million years ago, so our ancestors had to have lost the requirement to link clitoral stimulation to reproduction deep in the Cretaceous, yet still maintained the association between clitoral stimulation and orgasm to the modern day.

That retention is still best explained by the byproduct hypothesis -- the pleasure circuitry is maintained by ongoing selection for its operation in males, and there's no purpose to untangling it and removing it from females, and in fact, selecting for anorgasmia in females might have unfortunate reproductive side effects in males.

I'd also suggest that it doesn't answer another question: why does sex feel good? We have other urges that our physiology doesn't address by inducing super-charged sensations -- I mean, why don't we have wild orgasms every time we urinate? Why doesn't my thyroid send ripples of joy through my body when I balance my salt intake? If you've ever watched cats mating, you also know that sex for them is more a matter of compulsion than an opportunity to revel in pleasurable sensations by choice. Do salmon enjoy thrashing themselves to death? I might also argue that to some human males sex isn't a matter so much of feeling good as it is conquest, expressing dominance, and flaunting their social potency to their peers, so there are clearly alternative mechanisms to make sure males mate with females.

I might suggest that the mystery isn't the female orgasm, but the orgasm, period. But it's only a mystery if you insist on demanding a direct adaptive explanation for its existence.

pharyngula Tue, 08/02/2016 - 08:06

Tags

evolution

reproduction

Bill Nye and abortion

pharyngula — Thu, 01 Oct 2015 11:07:03 +0000

Bill Nye and abortion

Bill Nye talks about the realities of reproduction, and the right wing completely loses its shit.

It is not Nye at his most eloquent, but…he's actually right about everything important. Read this title for an example of the inanity of far right responses, titled WATCH: Bill Nye, Science Guy Makes An Idiot Of Himself On Reproduction. Nye is clearer and more correct than whoever wrote that, making it particularly amusing. It makes a lot of claims.

Not that this writer had all that great an affinity for Bill Nye anyway, but the video below has to be the most smug, snide, atheistic diatribe displaying outright willful ignorance and leftist talking points to grace youtube at least since Hillary Clinton talked about this subject.

No, no…that's my schtick. How can you watch that video and come away thinking Nye's attitude is offensive? Probably the same way one can watch it and thing he got everything wrong.

Over at National Review, a trio of physicians pick apart the arguments using actual peer reviewed medical journal articles, but we can sum up what they have to say pretty easily.

When a single sperm fertilizes a human egg, the resulting zygote – the one cell being – has its own unique DNA.

Life begins for any one human being at that moment of conception when this fertilization occurs.

Errm, if you look at the National Review article (which I'll return to shortly), it's by two authors, a lawyer and a bioethicist at a Catholic university; there are several other articles by a Fellow of the Discovery Institute. This isn't exactly a stellar, well-qualified lineup.

Their first point is a non sequitur. Fertilization produces a new unique genetic combination, but so what? This is the case in every organism -- we don't swoon in awe at the fact that fertilization in zebrafish produces a new combination of DNA. We don't declare meiosis a privileged, protected state because it produces gametes with a unique set of genes. We don't look at the immune system and decide that antibody producing cells are human beings because they reorganize their genomes into a unique arrangement during maturation.

Their second point is a standard elision: the process that will eventually produce a human being begins at fertilization, just like the process that will produce a chair begins when a tree is chopped down. We can apply the same adjective to both the tree and the chair -- "wood" -- but it doesn't make them synonymous.

This is the pure science of when human life begins. It is true that not every time an egg is fertilized it implants, and babies are lost due to natural causes every day. This is called an act of God, or if one is not religious, Mother Nature. Mr. Nye’s statements on that topic calling for the prosecution of women whose fertilized eggs do not implant in the uterine wall are patently stupid on their face.

It's a distortion and over-simplification of the "pure science". When Nye talks about prosecuting women whose eggs fail to implant, he's pointing out the fucking absurdity of such an argument, but if you're going to call them patently stupid, say it to lawmakers in Indiana and Georgia and many other places that want to criminalize contraception. How can you not know that one of the grounds for hating some forms of contraception is the idea that they prevent implantation?

“You wouldn’t know how big a human egg is if it weren’t for microscopes.” Uh, Bill…the human ovum is the only sort of cell in a woman’s body that can be seen with the naked eye.

It is true we would not know the gory details of the beauty of human reproduction without medical doctors putting cameras in some pretty private parts of women, but that does not cancel out the actual science itself that tells us a human being is created at fertilization.

That was written by a guy who's never had to find an ovum. They weren't even discovered in mammals until the 1830s. Identifying one relatively large cell in a tissue populated with trillions of cells isn't easy, and while mature follicles are even larger and easier to spot, it's still non-trivial to identify them without some magnification. I've got slides of ovaries in my lab, all nicely stained to make it even easier, but still…a dot that's only 100-150µm in diameter (a tenth of a millimeter) isn't something you'll be able to spot without a microscope.

Bill Nye might be a science guy (engineer, actually), but he’s no more an expert on human reproduction than Todd Akin is. What Nye is is a leftist tool who is spouting the feminist line that simplifies down to stupidity the excuses the left offers for why abortion should be tolerated in polite society, and why abstinence is undesirable as a way to prevent pregnancy when it is really 100% reliable as a way to do so. Without medical intervention, so far as we know, only one child was ever conceived without his mother knowing man. That has to say something for God.

At least we get an admission that Akin isn't an expert on human reproduction! But the rest is an evasion. Why shouldn't abortion be tolerated? He doesn't say. And the reliability of not having sex to avoid pregnancy is not under debate; it's that human beings are not reliably abstinent. We should endorse methods that allow people to be sexual beings without requiring them to be saddled with an unwanted pregnancy.

But let's go to that National Review article with the over-hyped authorities. It's not very good or convincing. The heart of their claim is that scientific publications acknowledge and justify that zygotes are human at fertilization.

All the texts used in contemporary human embryology and teratology, developmental biology, and anatomy concur in the judgment that it is at fertilization, not — as Nye ignorantly claims — at implantation, that the life of a new individual of the species Homo sapiens begins. Here are three of many, many examples:

“Human life begins at fertilization, the process during which a male gamete or sperm unites with a female gamete or oocyte (ovum) to form a single cell called a zygote. This highly specialized, totipotent cell marked the beginning of each of us as a unique individual.” “A zygote is the beginning of a new human being (i.e., an embryo).” (Keith L. Moore, The Developing Human: Clinically Oriented Embryology, 7th edition. Philadelphia, PA: Saunders, 2003. pp. 16, 2.)

“Fertilization is the process by which male and female haploid gametes (sperm and egg) unite to produce a genetically distinct individual.” (Signorelli et al., Kinases, phosphatases and proteases during sperm capacitation, CELL TISSUE RES. 349(3):765, March 20, 2012.)

“Although life is a continuous process, fertilization (which, incidentally, is not a ‘moment’) is a critical landmark because, under ordinary circumstances, a new, genetically distinct human organism is formed when the chromosomes of the male and female pronuclei blend in the oocyte” (Emphasis added; Ronan O’Rahilly and Fabiola Mueller, Human Embryology and Teratology, 3rd edition. New York: John Wiley & Sons, 2000, p. 8).

To which I can only say: NONSENSE. "Human" in these cases is a general descriptor for the origin of the cells; it's a statement about the type. You might as well say that that one quote about a "male and female haploid gametes (sperm and egg)" clearly states that sperm and egg are human, therefore science says we ought to criminalize menstruation and masturbation.

One other point I have to make about their sources: the Moore and O'Rahilly texts are specifically medical embryology textbooks -- they are not good sources for information about general developmental biology, and are a bit blinkered in their perspective, and tend to focus on superficial aspects of descriptive morphology. That's fine for medical and nursing students, I suppose, but if you want to actually understand the mechanics of development, they're useless. They're doubly useless if you read them with an agenda that refuses to be budged by the facts.

I can troll the scientific literature, too. Here are some titles.

Pass F, Janis R, Marcus DM. (1971) Antigens of human wart tissue. J Invest Dermatol. 56(4):305-10.

Warts are human! Ban squaric acid, laser surgery, and topical liquid nitrogen treatments! (Warts actually are human: they are made of skin cells stimulated into benign overgrowth by incorporation of genetic material from a virus. They also therefore have a unique genetic combination.)

Kim HB, Lee SH, Um JH, Oh WK, Kim DW, Kang CD, Kim SH. (2015) Sensitization of multidrug-resistant human cancer cells to Hsp90 inhibitors by down-regulation of SIRT1. Oncotarget. 2015 Sep 25. [Epub ahead of print]

Cancer cells are human! They are also genetically distinct from their host, with a unique molecular signature. All the arguments used by these people denying Nye's statements can also be applied to cancer.

Finch CE, Austad SN. (2015) Commentary: is Alzheimer's disease uniquely human? Neurobiol Aging. 36(2):553-5.

Uh-oh. Scientists refer to diseases as "human", too? Do we need to get informed consent and a signature from neurofibrillary plaques in the brain before we can try to treat it?

My point is not that warts, cancer, or diseases need to be regarded as persons. It's that "human" is a very broad term that is applied to a lot of kinds of cells, and it takes a particularly naive person to browse through the literature and go "A-ha! My biases are confirmed by this quote!" We clearly have an understanding of the distinction between the general term "human" and "person deserving full civil rights and the protection of society". If we didn't, everyone would have to go around the house collecting shed skin flakes to give them a properly reverent burial.

And please, can this fascination with genetically unique combinations just curl up and die? It's irrelevant and meaningless. A human being is not a cell or a listing of the nucleotide sequences of their genome. We leftist tools have a deeper appreciation of the breadth and depth of experience and information that makes us fully human than "right-wing ignoramuses", it seems.

Wait, what about the idiot from the Discovery Institute? What does he have to say? He's ignorable. Well, so are the other babblers at the National Review, so I'll just mention one thing. Wesley Smith says:

A sperm is a cell, it is alive but it isn’t a living organism. Ditto an egg.

Wha…? How does he define "organism"? That statement is so stupid it hurt to read it. I would like to see his definition, because it will require some twisty ad hoc bullshit to avoid being used to claim a zygote isn't an "organism".

Speaking of ignorable, one thing these critics ignore is women. Everything spins around how they can redefine terms, and how they can distort the scientific literature as an authority to back them up, but the primary argument for abortion is that women -- human beings that we can not dispute are fully functional, aware members of society -- must have autonomy and the right to control their bodies, and that society is better for everyone when women are respected as something more than baby-makers. They don't even try to touch that point.

pharyngula Thu, 10/01/2015 - 07:07

Tags

development

reproduction

Categories

Social Sciences

I really can't stand the hardcore pro-life crowd. They will bend over backwards to try to explain how a bundle of cells that is incapable of surviving outside of the environment of the womb is somehow automatically a full, complete person with full legal rights.

And when that fails, they will begin on the moral argument about how God doesn't want it, despite the fact that God specifically endorses forced abortions as a way to 'prove' the fidelity/infidelity of your wife/wives. It's right there in that old testament they love to quote so much.

They will go to all these lengths to try and force other people to have children they don't want/can't afford to raise properly... and they will also be the exact same people who are also vehemently against universal healthcare, or social programs to help support low-income families saddled with extra children, or widely available contraception, or actual sexual education.

There's a reason red states have some of the highest teen pregnancy and STD rates in the nation. It really bothers me as a southerner to see so many people so fighting so passionately against their own self-interests.

RC, this issue of how they can be FOR forcing a woman to have a child she can't afford and at the same time be against contraception can be understood when we remember that they also espouse abstinece only. The deep message is that they see forced pregnancy and the "ruin" of women as punishment for the sin of sex. You can see the collarary of this when they get upset at the idea of providing contraception to single young women... because sex should have nasty consequences and removing the consequences is promoting sin.

http://www.nationalreview.com/article/424721/bill-nye-youtube-abortion

PZ, Did you notice the part where they said a gamete is a human because "it just needs a suitable environment." Kinda ignoring the fact that the "suitable environment" is inside of a being that should be afforded full agency and therefore be able to decide to host the gamete or not. I didn't need to read any further after that, but I do appreciate your digging into the background of the authors they cited. Had a hunch they were probably biased, but damn the DI!? Ugh... The other thing that grossed me out was the title of the book that these two "writers" authored together. Full on cringe city.

Are we really surprised that folks on the right are so willing to lie about these things, and do it with such ease?

As a preface, two things:
a)The fight against abortion will NEVER end.
b)In my near 60 years, I’ve never seen a pro-abortion (a.k.a. “pro-choice”) argument that made any sense.

As to this article, I’ll take it from the top:

1)
If you’re going to dismiss the National Review piece because its authors are a lawyer and a bioethicist – “This isn’t exactly a stellar, well-qualified lineup” – why don’t you similarly dismiss Bill Nye, bachelors in mechanical engineering?

2)
“We don’t look at the immune system and decide that antibody producing cells are human beings because they reorganize their genomes into a unique arrangement during maturation.”

That’s because an immune system or an antibody will NEVER grow into what is universally recognizable as a human being.

3)
“Their second point is a standard elision: the process that will eventually produce a human being begins at fertilization, just like the process that will produce a chair begins when a tree is chopped down.”

No.
The process that produces a human being ENDS at fertilization. Reproduction is then complete.
All that remains is gestation/growth.

Your tree-to-chair analogy is profoundly invalid. A tree will NEVER grow naturally into the wooden rocking chair on the porch. Just as a human sperm call or an unfertilized human egg will NEVER be a human being.
Only the fertilized human egg will grow naturally into what universally recognizable as a human being. That is, the fertilized egg IS a human being, but will become more recognizable as such, even to a child, if it is allowed to grow.

4)
“When Nye talks about prosecuting women whose eggs fail to implant, he’s pointing out the f***ing absurdity of such an argument…”

That WOULD be absurd.
But that’s not the argument.
No one would be prosecuted for, say, a murder, when she could have had no influence on or control of the murder. And so it is with an egg naturally failing to implant.

However, one COULD be prosecuted for, say, a murder, when she did have an influence on or control of the murder. And so it is, when taking abortifacient contraceptives which unnaturally prevent the egg from implanting.

5)
“Why shouldn’t abortion be tolerated?”

Why shouldn’t murder be tolerated?
Why shouldn’t slavery be tolerated?

6)
“You might as well say that that one quote about a “male and female haploid gametes (sperm and egg)” clearly states that sperm and egg are human, therefore science says we ought to criminalize menstruation and masturbation.”

You MIGHT say that if you were a modern day idiot. Because, of course, neither the human’s sperm nor the human’s egg will grow into what are universally recognized as human beings.

A modern day idiot doesn’t understand the difference between a) a human being, and
b) a cell or organ OF/FROM a human being.
He thinks the latter is no more and no less important than the former. Such a person might as well say things like “We do not offer full rights and protections to everything that is “human”, or bleeding, spitting, and masturbation and menstruation would be illegal. Those acts also destroy living, human cells that cannot become donkey or cat cells.”

7)
“And please, can this fascination with genetically unique combinations just curl up and die? It’s irrelevant and meaningless. A human being is not a cell or a listing of the nucleotide sequences of their genome. We "leftist tools" have a deeper appreciation of the breadth and depth of experience and information that makes us fully human than “right-wing ignoramuses”, it seems.”

So, “leftist tools” like you will define “human being” for the rest us. I do hope you’ll PROVIDE THE DEFINITION here presently.

8)
“… the primary argument for abortion is that women — human beings that we can not dispute are fully functional, aware members of society — must have autonomy and the right to control their bodies, and that society is better for everyone when women are respected as something more than baby-makers. They don’t even try to touch that point.”

I’ll touch it.
The primary argument AGAINST abortion is NOT that women must have autonomy and the right to control their bodies. Women (and men) SHOULD have autonomy and the right to control their bodies.

The primary argument AGAINST abortion is that women (and men) must NOT have autonomy over, and the right to control, ANOTHER’s body (i.e. the baby’s body).
………………

I’ll end where I began:
a)The fight against abortion will NEVER end. (And I suspect the fight will grow ever more intense.)
b)In my near 60 years, I have never once seen a pro-abortion (a.k.a. “pro-choice”) argument that made any sense.

sn, your profound ignorance and unwillingness to read for understanding grows more amazing each time you demonstrate it. There really isn't much difference at all between you and the Muslim terrorists you've claimed to despise.

Dean I've read your comments where you call people liars and terrorists and can't help but notice that you present nothing in the way of proof to substantiate your claims. See Noevo on the other hand presents his case very clearly with a substantial amount of facts. It might interest you and others of your ilk to know that the American College of Obstetrics and Gynecology agree with SN's position. Now you may prefer to accept the ignorant statements/beliefs/claims of a gynecological genius such as Bill Nye since his mechanical engineering background certainly makes him much wiser than some dumb ole group of doctors and you can base many of your life's decisions using your obviously superior intellect but from where I sit, you seem to have the capacity of true rational thought that is somewhat similar to the thought process of an overfilled trash compactor. Good luck with that and for the good of all those around you, I hope someone occasionally comes by and hoses you down to get some of the garbage out.

dean, I second Scott's comment. Ironically, your response is in fact far closer to how a religious fundamentalist would deal with an argument they can't address.

I'm pro-choice (although for different reasons than most) but I don't like intellectual bullies any more than I like physical ones. Grow up and grow a pair, and if you've actually got the intellectual gonads to address See Noevo's points and can demonstrate why he's the equivalent of a Muslim terrorist for daring to disagree with you and your 'gang', well then, lets hear it.

Sn presents a case with facts? You really haven't looked at his comments around these blogs have you

- he'll believe in evolution when one animal gives birth to one another species as evolution predicts
- research in physics or any other science is worthless without the guidance of Catholic philosophy
- gays, lesbians, and trans gendered people are deformed beings and shouldn't be around decent people
- the current Pope has such an open mind his brain has fallen out
- nobody should spend time, or money, studying that that doesn't have an immediate application. (Interesting history there: he said that in Feb at Ethan's, after he had stated a result in cosmology was wrong, and had it demonstred several times he didn't know what he was talking about. Later, on another blog, it was brought up and he denied having said. We mentioned it was a quote. He said he never said it. A link was given. He said it didn't mean there had to be an application before someone could study it. Same thing happened recently.)
- look at the series of comments he made on several posts at evolution blog, and see whether you believe he argues with facts.

The response to him isn't because he disagrees with every aspect of modern science, it is because he not only does it with repeated lies and failure to respond when his errors are pointed out.

The comments about his racism, hatred of the poor, and dismissal of the importance of women's health and social issues, are due to his many comments against those groups. (Is is for women keeping quiet and having lots of babies the way good Catholic women are supposed to, but that's it). He has as vile as he described to be.
Read more if his comments and responses from all of us. Detailed presentation of facts don't matter with him. Those responsee are not insults but statements of fact.

@See Noevk said....

"That’s because an immune system or an antibody will NEVER grow into what is universally recognizable as a human being."

Neither will a zygote that fails to implant.

"The primary argument AGAINST abortion is that women (and men) must NOT have autonomy over, and the right to control, ANOTHER’s body"

I'm sure you meant to include fetuses in your list, since they are human beings in your eyes, yes? So it should be "women, and men, and fetuses, must NOT have autonomy over, and the right to control, ANOTHER'S body."

To Peter Zachos #11:

Me: “That’s because an immune system or an antibody will NEVER grow into what is universally recognizable as a human being.”

You: “Neither will a zygote that fails to implant.”

I agree 100%.
Nevertheless, the zygote (i.e. fertilized human egg) IS a human being. But it won’t grow into what is *universally recognizable* (e.g. immediately recognizable even by a child) as a human being if it fails to implant, or if, say, it implants but is then knowingly and deliberately destroyed by, say, Planned Parenthood.
...............
Me: “The primary argument AGAINST abortion is that women (and men) must NOT have autonomy over, and the right to control, ANOTHER’s body”

You: “I’m sure you meant to include fetuses in your list, since they are human beings in your eyes, yes? So it should be “women, and men, and fetuses, must NOT have autonomy over, and the right to control, ANOTHER’S body.”

Well, technically, “yes”.
But for any practical, sane, reality-based purpose, “no”.
Unless perhaps you ever heard of a controversial case whereby the “fetus” decided to murder his mother because the mother was inconvenient to his purposes or threatening his health?
If so, please provide a link to the story. I’d be fascinated to hear that fetus’s rationale for making his serious and agonizing decision to take control of the mother’s body and kill it.

Nye's video is really poorly done. His arguments fall very flat. He is arguing against one straw man after another. First how is a death of a zygote by natural causes the same as abortion? Nye makes this point when he asks who are we going to sue if the zygote is a human being? That is nonsense.

Second I do not know of anyone who is rejecting his science. When a homo sapien has all the rights as a human being is not a scientific question. Science can gives us some information to answer this question but ultimately it is an answer for philosophy. Nye worldview gives him the reasons to state that just a fertilized egg should not have all the rights as a grown human being. Again science really does not answer this question. So stating that Nye uses science to debunk the pro life argument is not true.

I think (I hope i misunderstood this argument) that Nye said Christians and the Bible argue that every time someone has sex that a woman gets pregnant. Who believes this? No Christian I know. Maybe some little kid somewhere ;) The bible clearly does not argue for this either although I do not think it tries to answer that question. Another strawman.

I could go on but ultimately it is unecessary. There was nothing in Nye's video that helped the pro-choice cause. If these are the best pro-choice arguments then the movement is in trouble. Nye's video was about as poor as I have ever seen.

I'm quite sure if See Noevo was forcibly implanted, he/she would find a good argument for abortion. Fairly quickly.

As for his wanting to see a story of a fetus murdering it's mother, he must be blind, deaf and dumb. They happen all the time. Getting pregnant is a very dangerous job, even with modern medicine and, in most modern industrialized countries, health care for all, women still die from pregnancies. I'll provide one:
https://en.wikipedia.org/wiki/Death_of_Savita_Halappanavar

The real question he fails to answer, is why should a fetus have more rights than an adult human being? Why should a fetus have the right to borrow a womans body? Why not her six month old child, if it needs a liver or kidney? No consent needed, the government can just strap her down and take it. Her liver will grow back, if they take a small piece, and she doesn't need two kidneys.

Otherwise, the fetus gets special rights, which it loses when it's born. That makes no sense. Nor does it make sense to give more rights to a fetus that has no brain cells, never mind a brain. A human without a brain is not a human, it's body, a lump of flesh. The same with a fetus. But we see people who are willing to give it more rights than a full grown adult woman. Perhaps we should, instead of aborting that fetus, remove it and implant it into the abdomen of the anti abortionists. With, or without their consent. Then when it's viable, it can be removed, put in a preemie ward, and then they can raise the child. I bet that would put a whole new spin on their outlook.

Every argument I've ever had with anti abortion person always comes down to:

Because she has to be responsible for the sex she had.

Bringing the conversation back to the second comment, which was written by Candice.

To Jeremy Beck #14:

“I’m quite sure if See Noevo was forcibly implanted, he/she would find a good argument for abortion. Fairly quickly.”

I have no idea what you mean.
.....................
“As for his wanting to see a story of a fetus murdering it’s mother, he must be blind, deaf and dumb. They happen all the time.”

Apparently you have no idea what “murdering” means. Check the dictionary.
..............
“The real question he fails to answer, is why should a fetus have more rights than an adult human being? Why should a fetus have the right to borrow a womans body?”

I don’t think a baby should have MORE “rights” than an adult, just the same “rights” (“Rights” as in basics, like the right to life.)

As far as the “body” question, I think civil society and current law enforcement would not think twice about prosecuting a mother who deliberately failed to use her body to feed her new born baby - whether by her body’s breast or by her body’s hand spooning Gerbers.

Things like the amniotic sack and umbilical cord are just other means of using one body to sustain and feed another body.

Jeremy, don’t you believe in taking care of the least among us, those who can’t take care of themselves through no fault of their own? I bet you do.
............
“Why not her six month old child, if it needs a liver or kidney? No consent needed, the government can just strap her down and take it.”

We were talking apples and now you’re talking oranges.
We were talking about the simple, natural process of a mother providing nourishment; that it’s right to provide and receive such nourishment.
But no one has a right to take another’s organs.
..................
“Every argument I’ve ever had with anti abortion person always comes down to: Because she has to be responsible for the sex she had.”

Except the argument you’re trying to have with me.

"I don’t think a baby should have more rights, just the same rights"

They do. A fetus is not a baby you moron.

This is not science, this is your pure views of abortion.

dean is right about See Noevo. It is absolutely correct to dismiss him. He's a bigot and an idiot.

How about the possibility that homosexuality is evil?

The thing dean is wrong about is that See Noevo is not a very strict Catholic.

I think Pope Francis’ encyclical was largely, but not entirely, a disgrace of ignorance and lefty-politics.

He's a right wing nut but who uses religion to justify his beliefs. It's an understandable mistake; I too once said his radical unbending beliefs were of the same vein Muslim terrorists. There's no reason to be civil with him. Under any pretense of reason he gives lie inviolable beliefs.

It's an arguing with a dining room table situation. All you'll do is tire yourself out. It's kind of fun though because the longer you can keep the thread going the more gems you get from him. No one discredits See Noevo better than himself. Here's another of my favorites from that RI thread:

*The so-called pedophilia problem in the RCC is really primarily a homosexual problem.*

To be more on topic, See Noevo is an absolutist. He has said that he would be against abortion even if it was a 9 year old rape victim with a life threatening pregnancy. To be fair, I am fully on the other side; I think someone using abortion as birth control is morally questionable at best but I don't think it's my place to forcibly impose my moral beliefs onto others.

This is where the comparison to radical terrorists comes in. Villianizing the women who get and doctors who perform abortions (or contraception depending on how far down the rabbit hole you are) as murderers justifie violence against them. It's the very same rhetoric that radical Muslims use to incite violence against against blasphemers and infidels.

Looking at the content of See Noevo's arguments here it seems to boil down to, a zygote will eventually grow into a human and PZ Meyers' comparisons are unfounded because they will not grow into a human. I have two issues with this.

First, this is not an accurate portrayal of his beliefs. Like I said before See Noevo, like many pro-lifers, is an absolutist. Consider an ectopic pregnancy implanted in the fallopian tube. This will never develope into a human but will very likely kill the mother if left alone. Yet, terminating it is still murder. Indeed, there are some Catholic hospitals that will not do anything until it ruptures.

Building on that point, a more accurate statement is that a zygote will eventually develop into a human under the right circumstances. It needs to implant (in the right place), it needs adequate nutrition, it needs luck not to be miscarried, and it needs mom to stay alive.

In the same way, under the right circumstances (i.e. sperm present to fertilize it) an egg will develop into a zygote and subsequently a human. A zygote is more likely to develop to a human but it's not guarenteed. There's a chance either of them will develop into a human. At what percentage is the cutoff (i.e. 50% of zygotes become humans so they are humans, 1% of eggs become humans but they are not humans).

For what it's worth I think life begins at viability. That said I don't go around calling women who get or doctors who perform late term abortions murderers. No matter what else, I think using loaded language to incite others to violence is always wrong.

"The thing dean is wrong about is that See Noevo is not a very strict Catholic."

I agree with the point: sn is is a strict Catholic as long as the Pope's statements agree with his. He had no problem, for example, with the fact that the two previous popes did everything they could to protect priests who had abused and raped children. He does have a problem with the fact that the current pope is not that drastic in his actions.

dean@20
I see now you already made that point in #10. Read things all the through first I guess.

Also, I'm beginning to think the comparison to radical Islam is still apt unlike what I said before (actually even more so). I'm no scholar on Islam but my understanding is that the terrorists preach a bastardized form that conforms to their beliefs. Just like See Noevo's warped interpretation of Catholicism. Couple that with loaded, dehumanizing language against those he dislikes and misogyny and thethey really should be besties.

Side note, if abortion bothers you so, might not a better way to deal with it be addressing the social issues that lead women to get them? Of course education about contraception is also immoral to him so... Speaking of contraception anyone how this statement is at odds with the anti-contraception belief?

See Noevo@6

You MIGHT say that if you were a modern day idiot. Because, of course, neither the human’s sperm nor the human’s egg will grow into what are universally recognized as human beings.

I know being consistent with reality is a tough proposition but is expecting internal consistency too much to ask?

“Looking at the content of See Noevo’s arguments here it seems to boil down to, a zygote will eventually grow into a human and PZ Meyers’ comparisons are unfounded because they will not grow into a human.”

Poor crunchy. Still not looking.

But thanks for bringing up the mammoth 2182 comment http://scienceblogs.com/insolence/2015/07/27/when-the-antiabortion-move…

Perhaps others can learn from that thread, also.

Yes sn, they will learn from that RI thread - quite a bit about your lack of integrity and knowledge, mostly.

See Noevo@22

Poor crunchy. Still not looking.

There it is! The wholely unjustified condescension. The ignoring any counterpoint made. Classic See Noevo.

Is the problem that I left out "universally recognized as a". Sure. Substitute it in a read again. Doesn't change the substance of what I said.

@dean
If you're looking for a good laugh, check out gaist's See Noevo parody starting at #1938. It continues on for a while just CTRL F for gaist.

To capnkrunch #24:

You: “Looking at the content of See Noevo’s arguments here it seems to boil down to, a zygote will eventually grow into a human and PZ Meyers’ comparisons are unfounded because they will not grow into a human.”

Me: “Poor crunchy. Still not looking.”

You: “Is the problem that I left out “universally recognized as a”.”

No, not exactly.
That would misleadingly state my position thusly:
‘See Noevo’s arguments here it seems to boil down to, a zygote will eventually grow into what is universally recognized as a human being.’
But that would be misleading and incomplete.

No, my repeatedly-stated ACTUAL position is like THIS:
‘See Noevo’s arguments here boil down to a zygote IS A HUMAN BEING which will eventually grow into what is universally recognized as a human being.’

Do you see the difference, crunchy?
I bet you do, and you did.

Yes sn, it's clear: your position is based on personal ideology rather than anything relating to science. No surprise.

See Noevo@25
I suppose internal consistency really is too much to ask. Did you stop reading after the first part or are you being willfully obtuse?

...and PZ Meyers’ comparisons are unfounded because they will not grow into a human.

You included that part, I wonder if you read it though.

That’s because an immune system or an antibody will NEVER grow into what is universally recognizable as a human being.
...
You MIGHT say that if you were a modern day idiot. Because, of course, neither the human’s sperm nor the human’s egg will grow into what are universally recognized as human beings.

Do you not see how this really invalidates your arguments against PZ Meyers' examples?

‘See Noevo’s arguments here boil down to a zygote IS A HUMAN BEING which will eventually grow into what is universally recognized as a human being.’

Let me explain. Per your own words, growing into what is ubiversally recognized as a human being is not what makes something human. We're back to where we started, you have simply asserted a zygote is a human. An ectopic pregnancy, like an antibody producing cell will never grow into what is universally recognized as a human being. The argument for either one being a human is equally valid.

More pointedly:

Just as a human sperm call or an unfertilized human egg will NEVER be a human being.
Only the fertilized human egg will grow naturally into what universally recognizable as a human being.

Interesting observation: an unfertilized egg or a sperm cell actually has a far greater chance of growing into what is universally recognized as a human than an ectopic pregnancy.

So, See Noevo's arguments might be cloaked in a guise of rational thinking but it boils down to personal ideology as dean notes in #26. In the end I think Carl Peterson hit the nail on the head in #13.

When a homo sapien has all the rights as a human being is not a scientific question.

Major difference between the two sides is that one thinks it's ok to use violence to impose its beliefs on everyone under the guise of fighting evil. Hence the comparison to terrorists.

capnkrunch@24: That is amazingly funny, but the funniest (in a sad way, actually) was this:

Because at the end of Sunday night, I’ll be essentially shutting this thread down.
See, early Monday morning I’ll be heading out of town for a week for a golf tournament, and will be “off grid.” This thread will go concomitantly comatose.

(as well as his other reminders that he is important enough to have a golf date planned.)
If I had not had the radio playing I believe I would have heard his little foot stomp as he typed the final period.

To capnkrunch #27:

“I suppose internal consistency really is too much to ask…”

No need to ask. My argument was entirely consistent.
The ONLY thing that grows into what is *universally recognizable* as a human being (e.g. immediately recognized as a human being *even by a small child*) is the fertilized egg.
Not a sperm, not an unfertilized egg, not an immune system, not an antibody, not ANYTHING else.
That’s because none of those last things are human beings. The fertilized egg IS a human being.
………..
The “modern day idiot” statement stands.
…………
“Let me explain. Per your own words, growing into what is ubiversally recognized as a human being is not what makes something human. We’re back to where we started, you have simply asserted a zygote is a human.”

Let me explain. We disagree on what defines a human being and science cannot settle the disagreement other than to say 1) life begins at conception and 2) that life that begins at conception has the complete set of DNA that is unarguably human DNA.
..................
“Interesting observation: an unfertilized egg or a sperm cell actually has a far greater chance of growing into what is universally recognized as a human than an ectopic pregnancy.”

No, an idiotic observation.
An unfertilized egg or a sperm cell has ZERO chance of growing into what is universally recognized as a human, because neither is a human being and never will be.
..................
“So, See Noevo’s arguments might be cloaked in a guise of rational thinking but it boils down to personal ideology…”

As are your arguments ideological.
However, the difference is that my “ideology” of when human life (i.e. a human being) begins is supported by scientific facts (see 1 & 2 above) and is not subject to arbitrary, non-scientific benchmarks of what constitutes personhood.
.............
“In the end I think Carl Peterson hit the nail on the head in #13. “When a homo sapien has all the rights as a human being is not a scientific question.””

I agree.
But as I said directly above, my position is supported by science and is non-arbitrary.
.............
“Major difference between the two sides is that one thinks it’s ok to use violence to impose its beliefs on everyone under the guise of fighting evil. Hence the comparison to terrorists.”

I would say that one side - the pro-abortion side - thinks it’s ok to use violence to impose its desires (i.e. aborting two thousand to three thousands human lives every day).
I would say that’s a type of terrorism.

In contrast, how many humans are killed by pro-lifers every day and how many other acts of violence are committed by pro-lifers every day?
How many in the last 40 years?

See Noevo@29
blockquote>Let me explain. We disagree on what defines a human being and science cannot settle the disagreement other than to say 1) life begins at conception and 2) that life that begins at conception has the complete set of DNA that is unarguably human DNA.
Now what science says that? A zygote is as alive as any other cell but claiming that it is a person has circled fully around to what PZ Meyers discussed in the article.

An unfertilized egg or a sperm cell has ZERO chance of growing into what is universally recognized as a human, because neither is a human being and never will be.

So zygotes just spring into existences as fertilized eggs?

I would say that one side – the pro-abortion side – thinks it’s ok to use violence to impose its desires (i.e. aborting two thousand to three thousands human lives every day).
I would say that’s a type of terrorism.

If you can't see why bombing an abortion clinic is terrorism and a woman voluntarily getting an abortion isn't I really don't know what else to say. Go purchase a Merriam-Webster I and look up terrorism I guess.

To capnkrunch #30:

Me: “An unfertilized egg or a sperm cell has ZERO chance of growing into what is universally recognized as a human, because neither is a human being and never will be.”

You: “So zygotes just spring into existences as fertilized eggs?”

Of course not.
But what does science say is the source of zygotes, or more specifically, the SOURCE of the sperm and egg whose union makes a zygote?
……………
“If you can’t see why bombing an abortion clinic is terrorism and a woman voluntarily getting an abortion isn’t I really don’t know what else to say.”

You didn’t answer my questions:
How many humans are killed by pro-lifers every day and how many other acts of violence are committed by pro-lifers every day?
How many in the last 40 years?
[Please provide links to stories of two recent murders, bombings or other violent acts by pro-lifers.]

Yikes, I'm not even sure what point SN is even trying to make half the time anymore. But, anyway, that's not what I was going to say. I'm just going to say my piece right quick: I feel like pro-choicers need to move the argument away from "when life begins" because anti-abortionists are never going to let that one up and are going to continue to come up with new arguments about how half-formed potential humans have the same rights as humans, therefore meaning that they have the right to put their host's life and health at risk without the host's consent and even away from "women's rights" and how those of us with the potential to become pregnant should have the basic human right to chose whether or not we're going to put our health and financial wellbeing at risk to squeeze a tiny human out of our cootches and not be forced to do so because they're always going to say "what about the baby(see: half-formed potential human)'s rights?" Instead, we should be moving the argument back to what's so pro-life about being pro-life? If you're so hell-bent on these children being born into this increasingly over-populated planet, why the hell don't you care about them after they're born? Why aren't you out there adopting all the children born to parents who couldn't or wouldn't raise them and don't have a safe, reliable home and family and urging everyone else to do the same instead insisting on splitting out more mini-humans who share parts of your genetic makeup? Why aren't you up in arms about making regular, good-quality schooling and healthy available to all children? Why aren't you focusing all your energy on making sure every human has access to the good food, clean water, shelter, employment, and education they require for life rather than forcing families into poverty to carry a child they weren't prepared for to term? Maybe I'm unique in this view (fun fact: that was a lie; I know I'm not), but I would much rather have been aborted than have to grow up in poverty because my parent(s) had to spend more money than they had ensuring both my and their health over the term of pregnancy, live in an abusive family because my parents never wanted me to begin with, or live in the mercy of foster care and "the system", able to do little more than hope that someone will adopt me and give me a stable, healthy environment to grow and develop into an adult with a chance at a happy, fulfilling life.

Because I don't see why "when human rights begin" is such a big deal when we already have millions of humans out there without access to their rights and so-called "pro-lifers" don't bat an eye at their suffering because they're not a "developing human". (Y'know, like us uterus-owners who have to give up our rights to health and bodily autonomy because we had the gall to let a penis inside us without intending a miniature human to result. Yeah, I'm losing track of my own point, but it really squicks me that anti-abortionists prioritize fetal rights over all others to the point that I have to make my former point at all.)

Also, @SN, please show us your sources for how many abortions you claim are happening each day before expecting anyone else to answer your question. I would ask for a "reliable, unbiased" source, but, honestly, I'd be surprised if you even knew what that means. Here's a hint: any "pro-life" website does not count. Medical or statistical sites do.

"aborting two thousand to three thousands human lives every day"? Worldwide? In America? Some other country? What about the type of abortion? Does this include medically necessary abortions (ie, the pregnant person will die if the fetus is not aborted due to complications, the fetus has some medical issue or deformation that prevents its development or will make its life outside the womb impossible), which I'm sure at this rate you'd protest anyway? Does it include an estimate of abortions done outside of professional medical situations (ie, "home abortions") or just surgical or chemical abortions done in a safe medical environment? You can't spew random numbers and expect a response, and you especially cannot expect links to sources after you do not include any yourself. I'm sure you don't realize how hypocritical it is to use vague "facts" without any backing to prove your point while expecting your opposition to prove their point with two reliable website sources, ten peer-reviewed articles, and a ten-page essay with full bibliography.

Yay Sage Rose! Thank you for bringing the discussion back to its most salient point.

I thought this blog was about *science*.

A fertilized egg contains unique human DNA, therefore the fertilized egg is human. The fertilized egg has the capacity for growth, reproduction, functional activity, and continual change preceding death, so this makes it life. So what we have currently is human life, much like you are human life.

Your argument isn't whether it is human, it obviously is, or whether it is living, it obviously is. Your argument is whether a certain class of human beings gets civil rights.

So morally, I am not allowed to knife you in the forehead. But I'm allowed to scrape you from your mother's womb. That's the argument you appear to be making.

Tony: But surely, it's more complex than that.

With In Vitro fertilization, you may end up with several fertilized eggs, some of which are selected for insertion.

Those that aren't selected are, according to your definition, human. Dismissing them from insertion essentially dooms them to death.

What you're saying (I think) is that not inserting those fertilized eggs is the same as knifing you in the head then? (your example, to avoid confusion)

Sedef cilt hastalıklarının başında gelmektedir. Özellikle ciltte ilerleyen zamanlarda beyaz lekelerin daha fazla büyümeye başlaması sonrasında, istenmeyen bir görüntüye sahip olabilirsiniz. Bu hastalığın en büyük düşmanın ise stres olmasından dolayı, stresten uzak durmanız sizin için çok önemli olacaktır. Sedef hastalığı genel olarak cildinizin, teninize bağlı olan sinirlerin güçsüz olmasından dolayı oluşmaktadır. Kronik bir hastalıkta olması nedeni ile ailenizden size kalıcı olarak geçebileceği gibi, sadece sizde de olabilir ve sizden çocuklarınıza da geçebilirsiniz. Bugün Sedef tedavisi günümüzde mümkün olmasından dolayı, bunun için en etkin ürün olarak krem önerilmektedir. Doktorlar tarafından da önerilen bu kremi kullanarak, istediğiniz gibi sorunlarınızı aşabileceğiniz için, ürün satın almak ve kullanmaya başlamak için www.sedefkrem.com sitesi üzerinden alışveriş yapabilirsiniz. Böylelikle Sedef kremi alarak, düzenli kullanım ile birlikte artık Sedef hastalığı için en doğru ürünü kullanmaya başlayarak, en iyi şekilde sorunlarınızı aşabileceksiniz.

Sedef Tedavisi Kremi Kullanın
Ciltlerinin pürüzsüz olmasını isteyen bayanların öncelikli olmasından dolayı, artık istediğiniz gibi Sedef tedavisi için krem alarak kullanmaya başlayabilir ve cilt sorunlarınızı kısa sürede çözebilirsiniz. Kremin tamamen bitkisel bir ürün olmasından dolayı, hiç bir şekilde size zarar vermeyeceği gibi, özellikle doğru kullanım sonrasında tüm cilt sorunlarınızı aşmanız mümkün olacaktır. Bunun yanında teninizin ve sinir sisteminizin ihtiyacı olan besinleri, vitaminleri ve mineralleri de alıyor olmanızdan dolayı, artık Sedef kremi sayesinde, sizlerde Sedef hastalığı sorunlarından kurtularak, doğru bir ürün kullanmanın imkanlarından en iyi şekilde yararlanmış olacaksınız.
Sizlere önermiş olduğumuz firma sayesinde en iyi Sedef kremini kullanmanız mümkün olabilecek ve krem sayesinde düzenli bir kullanım ile birlikte, artık Sedef tedavisi için sizlerde en iyi ürünü kullanmış olacaksınız. Böylelikle sizin için Sedef hastalığı artık bir sorun olmayacak ve tabi ki cildinize çok daha iyi bir şekilde bakma imkanına sizlerde sahip olabileceksiniz

The fertilized egg has the capacity for growth, reproduction, functional activity, and continual change preceding death, so this makes it life. So what we have currently is human life, much like you are human life.

How amazing that you include the word "potential" but then ignore its meaning.

City life makes bigger spiders

dr. dolittle — Sat, 23 Aug 2014 19:52:30 +0000

City life makes bigger spiders

A new study from researchers at the University of Sydney shows that golden orb-weaving spiders (Nephila plumipes) that live in the city are larger and produce more offspring as compared to country living.

When they say the spiders are big, they mean really big. The females can reach up to 20-25mm (males are only ~5mm).

Image from Spiders of Australia
http://ednieuw.home.xs4all.nl/australian/nephila/Nephila.html

The researchers speculate that the urban heat island effect, which is attributed to a lack vegetation and hard surfaces, may lead to the increased body size as invertebrates in warmer climates tend to be larger. Further, they speculate that the abundance of insects attracted to urban lighting (i.e. spider food) also promotes growth and reproductive success.

Sources:
Lowe EC, Wilder SM, Hochuli DF. Urbanisation at Multiple Scales Is Associated with Larger Size and Higher Fecundity of an Orb-Weaving Spider. PLoS ONE 9(8): e105480. doi:10.1371/journal.pone.0105480

University of Sydney press release

dr. dolittle Sat, 08/23/2014 - 15:52

Tags

Last I checked, climate scientists were in agreement that increase in mean global temps would produce localized increases in the sizes of insects and arachnids.

That might actually be useful in scaring some undecideds into thinking about climate change.

Big

Hairy

Spiders!

Eeek! OK, solar, wind, nuclear, whatever it takes!

Interesting point made pertaining to spider food being attracted to urban light. The artificial night lighting attracts many insects to a certain spot, making it easier for spiders to consume more prey. Discovery posted an intresting article that contains more facts about how Urban areas promote spider growth - (http://news.discovery.com/animals/insects/some-spiders-grow-bigger-in-u…)

Last Week on ResearchBlogging.org

milhayser — Sun, 06 Apr 2014 22:27:32 +0000

Last Week on ResearchBlogging.org

Perovskite solar cells can not only emit light, they can also emit up to 70% of absorbed sunlight as lasers.

Critical signaling molecules can be used to convert stem cells to neural progenitor cells, increasing the yield of healthy motor neurons and decreasing the time required to grow them.

Mexican blind cavefish are so close to their sighted kin that they are considered the same species, but they use pressure waves (from opening and closing their mouths) to navigate in the dark.

Electrostatic assembly allows luminescent elements (like Europium) to be embedded in nanodiamonds; these glowing particles "can be used as biomarkers, allowing researchers to track things that are happening inside cells."

In a rather cruel experiment, researchers tortured male rats by isolating them, depriving them of food and water, clamping their tails, shocking them with electricity, dunking them in cold water, placing them in soiled bedding, and keeping the lights on all night. Then they cut off and dissected the rats' testicles to look for signs of stress in their reproductive cells.

On the brighter side of testicular slices, researchers have shown that cancer cells cannot survive a new process for removing and freezing a sample of testicular tissue from boys with cancer. The process could allow patients to sidestep infertility caused by radiation and chemotherapy by implanting spermatogonial stem cells back into survivors when they reach adulthood.

A newly engineered bacterium can better manufacture pinene, "a hydrocarbon produced by trees that could potentially replace high-energy fuels, such as JP-10, in missiles and other aerospace applications."

Weather extremes don't always cause crops to fail; extra rain (as opposed to drought) can boost yields significantly, but it also boosts mosquito populations and the prevalence of mosquito-borne disease.

People with children "experienced less physical pain, felt they had more enjoyment in their lives, earned higher incomes, were better educated, and were healthier" than childless individuals, but still reported lower overall life satisfaction.

Like everyone else, most prisoners feel they are kinder and more moral than the average person; they also feel they are equally law-abiding.

Male wasps mouth the antennae of females during coitus to make them horny (with an oral pheromone), but a second exposure to the pheromone causes a lady wasp to lose interest in "unlocking her genitals" and start looking for fly larvae to deposit her eggs in.

Mafia members, despite their violent lifestyle, are highly social and not likely to be psychopaths.

Using more wood in building construction could reduce CO₂ emissions related to the manufacture of steel and concrete while maintaining sustainable forestry practices.

New research replicates a pioneering 19th-century study of blood flow to the brain during cognitive processing.

Some children with autism respond favorably to naltexone, an opiate antagonist, but the drug did not demonstrate an impact on core features of the disorder.

Dogs placed in foster homes—dressed in "Adopt Me" vests and taken to public places—relieve crowding in animal shelters and are more likely to be adopted for the long-term.

Many "hot" foods, like capsaicin, activate the TRPV1 receptor; deceptive showmen apply ginger to the anuses of older horses to make their tails more erect.

Growing soccer players at elite levels of play are more likely to develop cam deformities of the hip.

A patient who lost his hippocampus in a motorcycle accident (and his ability to form new memories) still understands the concepts of past and future, yet he has no regrets, and cannot imagine anyone having regrets (even Richard Nixon).

Hybrid cars get better gas mileage in countries like India and China due to higher levels of traffic congestion.

Among 65,226 UK residents, eating 7 servings of fruits and vegetables per day reduced risk of death from all causes by 42%.

milhayser Sun, 04/06/2014 - 18:27

Pathways to sex

pharyngula — Tue, 11 Mar 2014 17:08:05 +0000

Pathways to sex

I was talking about sex and nothing but sex all last week in genetics, which is far less titillating than it sounds. My focus was entirely on operational genetics, that is, how autosomal inheritance vs inheritance of factors on sex chromosomes differ, and I only hinted at how sex is not inherited as a simple mendelian trait, as we're always tempted to assume, but is actually the product of a whole elaborate chain of epistatic interactions. I'm always tempted in this class to go full-blown rabid developmental geneticist on them and do nothing but talk about interactions between genes, but I manage to restrain myself every time -- we have a curriculum and a focus for this course, and it's basic transmission genetics, and I struggle to get general concepts across before indulgence in my specific interests. Stick to the lesson plan! Try not to break everyone's brain yet!

But a fellow can dream, right?

Anyway, before paring everything down to the reasonable content I can give in a third year course, I brush up on the literature and take notes and track down background and details that I won't actually dump on the students (fellow professors know this phenomenon: you have to work to keep well ahead of the students, because they really don't need to start thinking they're smarter than you are). But I can dump my notes on you. You don't have to take a test on it and get a good grade, and you won't pester me about whether this will actually be on the test, and you won't start crying if I overwhelm you with really cool stuff. (If any of my students run across this, no, the content of this article will not be on any test. Don't panic. Go to grad school where this will all be much more relevant.)

Onward. Here's my abbreviated summary of the epistatic interactions in making boys and girls.

The earliest step in gonad development is the formation of the urogenital ridge from intermediate mesoderm, a thickening on the outside of the mesonephros (early kidney), under the influence of transcription factors Emx2, Wt1 (Wilms tumor 1), Lhx9, and Sf1 (steroidogenic factor 1). Even in the earliest stages, multiple genes interact to generate the tissue! The urogenital ridge is going to form only the somatic tissue of the gonad; the actual germ cells (the cells that will form the gametes, sperm and ova) arise much, much earlier, in the epiblast of the embryo at a primitive streak stage, and then migrate through the mesenteries of the gut to populate the urogenital ridge independently, shortly after it forms.

At this point, this organ is called the bipotential gonad -- it is identical in males and females. Two genes, Fgf9 and Wnt4, teeter in a balanced antagonistic relationship -- Wnt4 suppresses Fgf9, and Fgf9 suppresses Wnt4 -- in the bipotential gonad, and anything that might tip the balance between them will trigger development of one sex or the other. A mutation that breaks Fgf9, for instance, gives Wnt4 an edge, and the gonad will develop into an ovary; a mutation that breaks Wnt4 will let Fgf9 dominate the relationship, and the gonad will develop into a testis (with a note of caution: the changes will initiate differentiation into one gonad or the other, but there are other steps downstream that can also vary). These two molecules may be the universal regulators of the sex of the gonad in animals: fruit flies also use Fgf and Wnt genes to regulate development of their gonads.

But the key to the genetic symmetry-breaking of selecting Fgf9 and Wnt4 varies greatly in animals. Some use incubation temperature to bias expression one way or the other; birds have a poorly understood set of factors that may require heterodimerization between two different proteins produced on the Z and W chromosomes to induce ovaries; mammals have a unique gene, Sry, not found in other vertebrates, that is located on the Y chromosome and tilts the balance towards testis differentiation.

Sry may be unique to mammals, but it didn't come out of nowhere. Sry contains a motif called the HMG (high mobility group) box, which is a conserved DNA binding domain. There are approximately 20 proteins related to Sry in humans, all given the name SOX, for SRY-related HMG box (I know, molecular biologists seem to be really reaching for acronyms nowadays). SOX genes are found in all eukaryotes, and seem to play important roles in cell and organ differentiation in insects, nematodes, and vertebrates. Sry is simply the member of the family that has been tagged to regulate gonad development in mammals.

If a copy of Sry is present in the organism, which is usually only the case in XY or male mammals, expression of the gene produces a DNA binding protein that has one primary target: a gene called SOX9 (they're cousins!). In mice, Sry is switched on only transiently, long enough to activate SOX9, which then acts as a transcription factor for itself, maintaining expression of SOX9 for the life of the gonad. Humans keep Sry turned on permanently as well, but there's no evidence yet that it actually does anything important after activating SOX9; it may be that human males neglect to hit the off switch.

SOX9 binds to a number of genes, among them, Fgf9. Remember Fgf9? The masculinizing factor in antagonism to the feminizing factor Wnt4? This tips the teeter-totter to favor expression of Fgf9 over Wnt4, leading to the differentiation of a testis from the bipotential gonad.

So far, then, we've got a nice little Rube Goldberg machine and an epistatic pathway. Sf1/Wt1 and other early genes induce the formation of a urogenital ridge and an ambiguous gonad; Sry upregulates Sox9 which upregulates Fgf9 which suppresses Wnt4, turning off the ovarian pathway and turning on the testis pathway.

But wait, we're not done! Sry/SOX9 are expressed specifically in a subset of cells of the male gonad, the prospective Sertoli cells. If you recall your reproductive physiology, Sertoli cells are a kind of 'nurse' cell of the testis; they're responsible for nourishing developing sperm cells. They also have signaling functions. The Sertoli cells produce AMH, or anti-Müllerian Hormone, which is responsible for causing the female ducts of the reproductive system to degenerate in males (if you don't remember the difference between Müllerian and Wolffian and that array of tubes that get selected for survival in the different sexes, here's a refresher). Defects in the AMH system lead to persistent female ducts: you get males with partial ovaries and undescended testicles. So just having the Sry chain is not enough, there are downstream genes that have to dismantle incipient female structures and promote mature properties of the gonad.

As the gonad differentiates, it also induces another set of cells, the embryonic Leydig cells. We have to distinguish embryonic Leydig cells, because they represent another transient population that will do their job in the embryo, then gradually die off to be replaced by a new population of adult Leydig cells at puberty. The primary function of Leydig cells is the production of testosterone and other androgens. The embryo gets a brief dose of testosterone early that initiates masculinization of various tissues, which then fades (fortunately; no beards and pubic hair for baby boys) to resurge in adolescence, triggering development of secondary sexual characteristics. Embryonic testosterone is the signal that maintains the Wolffian duct system. No testosterone, and the Wolffian ducts degenerate.

Just to complicate matters, while testosterone is the signal that regulates the male ducts, testosterone must be converted to dihydrotestosterone (DHT), the signal that regulates development of the external genitalia. Defects in the enzyme responsible for this conversion can lead to individuals with male internal plumbing, including testes, but female external genitalia. Sex isn't all or nothing, but a whole series of switches!

By now, if you're paying attention, you may have noticed a decidedly male bias in this description. I've been talking about a bipotential gonad that is flipped into a male mode by the presence of a single switch, and sometimes, especially in the older literature, you'll find that development of the female gonad is treated as the default: ovaries are what you get if you lack the special magical trigger of the Y chromosome. This is not correct. The ovaries are also the product of an elaborate series of molecular decisions; I think it's just that they Y chromosome and the Sry gene just provided a convenient genetic handle to break into the system, and really, scientists usually favor the easy tool to get in.

One key difference between the testis and ovary is the inclusion of germ cells. The testis simply doesn't care; if the germ line, the precursors to sperm, is not present, the male gonad goes ahead and builds cords of Sertoli cells with Leydig cells differentiating in the interstitial space, makes the whole dang structure of the testicle, pumping out testosterone as if all is well, but contains no cells to make sperm — so it's reproductively useless, but hormonally and physiologically active. The ovary is different. If no germ line populates it, the ovarian follicle cells (the homolog to the Sertoli cells) do not differentiate. If germ cells are lost from the tissue only later, the follicles degenerate.

Ovaries require a signal from the germ line to develop normally. One element of that signal seems to be factors associated with cells in meiosis. The female germ line cells are on a very strict meiotic clock, beginning the divisions to produce haploid egg cells in the embryo, even as they populate the gonad. These oocytes produce a signal, Figα (factor in germ line a) that recruits ovarian cells to produce follicles. The male gonad has to actively repress meiosis in the embryonic germ line to inhibit this signaling; male germ cells are restricted to only mitotic divisions until puberty.

Even before Figα signaling becomes important, there are other factors uniquely expressed in the prospective ovary that shape its development. In particular, Wnt4 induces the expression of another gene, Foxl2, that is critical for formation of the ovarian follicle. The pathways involved in ovarian development are not as well understood as those in testis development, but it's quite clear that there is a chain of specific genetic/molecular interactions involved in the generation of both organs.

Wait, you say, you need a diagram! You can't grasp all this without an illustration! Here's a nice one: I particularly like that cauliflower-shaped explosion of looping arrows early in the testis pathway.

The molecular and genetic events in mammalian sex determination. The bipotential genital ridge is established by genes including Sf1 and Wt1, the early expression of which might also initiate that of Sox9 in both sexes. b-catenin can begin to accumulate as a response to Rspo1–Wnt4 signaling at this stage. In XX supporting cell precursors, b-catenin levels could accumulate sufficiently to repress SOX9 activity, either through direct protein interactions leading to mutual destruction, as seen during cartilage development, or by a direct effect on Sox9 transcription. However, in XY supporting cell precursors, increasing levels of SF1 activate Sry expression and then SRY, together with SF1, boosts Sox9 expression. Once SOX9 levels reach a critical threshold, several positive regulatory loops are initiated, including autoregulation of its own expression and formation of feed-forward loops via FGF9 or PGD2 signaling. If SRY activity is weak, low or late, it fails to boost Sox9 expression before b-catenin levels accumulate sufficiently to shut it down. At later stages, FOXL2 increases, which might help, perhaps in concert with ERs, to maintain granulosa (follicle) cell differentiation by repressing Sox9 expression. In the testis, SOX9 promotes the testis pathway, including Amh activation, and it also probably represses ovarian genes, including Wnt4 and Foxl2. However, any mechanism that increases Sox9 expression sufficiently will trigger Sertoli cell development, even in the absence of SRY.

So that's what I didn't tell my genetics students this time around. Maybe I'll work it into my developmental biology course, instead.

Kim Y, Kobayashi A, Sekido R, DiNapoli L, Brennan J, Chaboissier MC, Poulat F, Behringer RR, Lovell-Badge R, Capel B. (2006) Fgf9 and Wnt4 act as antagonistic signals to regulate mammalian sex determination. PLoS Biol 4(6):e187

Ross AJ, Capel B. (2005) Signaling at the crossroads of gonad development. Trends Endocrinol Metab. 16(1):19-25.

Sekido R, Lovell-Badge R (2009) Sex determination and SRY: down to a wink and a nudge? Trends Genet. 25(1):19-29.

Sim H, Argentaro A, Harley VR (2008) Boys, girls and shuttling of SRY and SOX9. Trends Endocrinol Metab. 19(6):213-22.

Yao H H-C (2005) The pathway to femaleness: current knowledge on embryonic
development of the ovary. Molecular and Cellular Endocrinology 230:87–93.

pharyngula Tue, 03/11/2014 - 13:08

Tags

New book on sexuality in the animal kingdom

dr. dolittle — Fri, 17 May 2013 14:41:35 +0000

New book on sexuality in the animal kingdom

I was just digitally flipping through a new book called "Crime Against Nature", which describes various reproductive behaviors in the animal kingdom. It is written by an artist, Gwenn Seemel, not a scientist, so I cannot vouch for the scientific accuracy of the book as a whole. However, the illustrations are quite nice and the content is seemingly scandalous, which makes for an interesting read.

For example, did you know that male Dayak fruit bats can lactate to feed their young (True according to this article in Nature)?

Image from "Crime Against Nature", written and illustrated by Gwenn Seemel.

However, the notion that female spotted hyenas have a "penis" is not entirely accurate. It turns out that high-ranking alpha female hyenas are very aggressive and provide their developing offspring with higher levels of androgen (male sex hormone) than lower-ranking females in late pregnancy. This androgen boost increases the offspring's chance of survival as it makes them more aggressive at fighting for food and at mating earlier and more often than those receiving less androgen. The problem is that the high androgen levels damage the mother's ovaries and cause her clitoris to enlarge (up to 7 inches), thereby resembling a penis. Since the opening of the vaginal canal is at the end of the clitoris, it makes birthing a 2-pound cub through a 2-inch canal dangerous and often fatal for first time mothers. (Source: Michigan State University press release).

To judge the book for yourself, click here.

dr. dolittle Fri, 05/17/2013 - 10:41

Tags

Hmmm. Technically and anatomically a clitoris is a penis. Same structure. Like male nipples. I would certainly triple check before buying the notion that babies are delivered through the clitoris.

air max pas cher...

Wow that was unusual. I just wrote an incredibly long comment but after I clicked submit my comment didn’t appear. Grrrr… well I’m not writing all that over again. Anyway, just wanted to say fantastic blog!...

If it's still a clitoris, then it doesn't have an opening in it. If the urethra's moved up and merged into it, then it is a penis.