reproduction
esiegel | January 28, 2008Okay, so I got a question from my friend Tamara, who's a high school teacher in my hometown of New York City. It concerns a recent article she read on the front page of the New York Times about something funny that us scientists are calling Boltzmann Brains.
I've read this article three times since it was featured on the front page of the science section in the NYT and I'm still confused about the Boltzmann brain problem, it's (non?)validity, the reason it made it's way onto the front page and whether Emerson's philosophy about imagined worlds came from this...
There's a lot of interesting…
pharyngula | January 9, 2008This is probably a serious site. Probably. It could be satire, but the line between satire and Christianity is razor thin. Read Christian dating tips, and judge for yourself.
First rule of Christian dating: it's pretty much like going to church. Boring, chaste, and offering nothing but faint hopes. No intimacy is allowed, not even a kiss.
Choose to not kiss - At least until you are engaged to be married. Okay, this can be extremely difficult, but if you can follow this one dating tip then most of the others will happen naturally. Even kissing once you are engaged can be very dangerous. It's…
grrlscientist | December 17, 2007tags: researchblogging.org, blue tits, Cyanistes caeruleus, Parus caeruleus, sexual selection, mate choice, ornithology, female coloration, reproduction, maternal quality, evolution, birds, ornithology
In many bird species, the females are brightly colored, just as the males are, but the evolutionary reasons for brightly colored females is unclear. According to one hypothesis, because males and females share the same genome, their traits are similar. However, according to another hypothesis, there may also be selective pressures on females, just as there are on males, to develop brightly…
pharyngula | December 4, 2007Sex education and humor … how can anyone object to this?
I'm sure someone will.
pharyngula | November 21, 2007
A recent discovery in stem cell research is no minor event: researchers have figured out how to reprogram adult cells into a state that is nearly indistinguishable from that of embryonic, pluripotent stem cells. This is huge news that promises to accelerate the pace of research in the field.
The problem has always been that cells exist in distinct states. A skin cell, for instance, has one set of genes essential for its specific function activated, and other sets of genes turned off; an egg cell has different patterns of gene activation and inactivation. Just taking the DNA from a skin cell…
pharyngula | November 19, 2007A few little videos by way of the marvelous Kevin Hayden:
Ladies, did you know that you are just like a cardboard box? We're supposed to treat you delicately and with respect, just in case you've got something in your uterus. If you've had a hysterectomy or you're menstruating, though, and we know the box is empty, well, we don't have to worry about you so much.
Guys, did you know that you are followed everywhere by a mob of enthusiastic, hyperactive sperm? I love how both sexes can be objectified by the functions of our gonads.
I've shown the video for this one before, but I'm going…
pharyngula | November 9, 2007The New Humanist has an article on genetic modification of human beings, addressing some of the reservations of critics. John Harris is primarily taking on Jurgen Habermas, who seems to think genetic engineering is yucky.
Habermas has two objections to letting prospective parents tinker with their child's genes:
The child doesn't have the opportunity to give consent — "the power of those living today over those coming after them, who will be the defenceless objects of prior choices made by the planners of today". I don't see the objection, myself. Every parent makes lots of choices in which…
pharyngula | November 4, 2007No way — I've seen Gas and Little Monsters, so this review of his sex ed movie, Where did I come from? gets that part wrong. I think the video and the book Where did I come from? aren't actually that bad; it's cutesy, it doesn't take the whole ridiculous business too seriously, and it gets the job of telling the kids the essentials done without too much fuss. If you can find it and have a young kid who needs to have sex explained, it's worth watching together.
If they're much beyond 8, though, don't bother. They always know more than you think.
clock | September 27, 2007
When teaching human or animal physiology, it is very easy to come up with examples of ubiqutous negative feedback loops. On the other hand, there are very few physiological processes that can serve as examples of positive feedback. These include opening of the ion channels during the action potential, the blood clotting cascade, emptying of the urinary bladder, copulation, breastfeeding and childbirth. The last two (and perhaps the last three!) involve the hormone oxytocin. The childbirth, at least in humans, is a canonical example and the standard story goes roughly like this:
When the…
pharyngula | September 18, 2007Now the Catholic schools want to ban the HPV vaccine. I simply do not understand that attitude. I can understand wanting to protect your daughter from the entanglements and risks of too-young sex, but this is a vaccine to protect them 1) from a disease 2) transmitted by sex. My eyes tend to focus more on point 1 than on point 2; 1 has greater penalties and none of the joys of 2, and protecting against 1 does not entail that 2 will occur.
Is there something in those communion crackers that shorts out the logic circuits of the brain?
pharyngula | August 21, 2007Yesterday's discussion of future biological advances that will piss off the religious right had me thinking about other innovations that I expect will happen within a few decades that might just cause wingnuts to freak out. First thing to come to mind is that it will be something to do with reproduction, of course, and it will scramble gender roles and expectations…so, how about modifying men to bear children? It sounds feasible to me. Zygotes are aggressive little parasites that will implant just about anywhere in the coelom — it's why ectopic pregnancies are a serious problem — so all we…
pharyngula | August 10, 2007Here is an excellent article on the biology of sexual orientation. We all know this is a contentious issue — are we born with an orientation, or is it a 'choice' that people make? — and the article just lays the facts out for us and points out some of the lacunae in our knowledge.
First, I'll confess to my own position on that nature-nurture debate: it's both and it's neither, and the argument is misplaced. There is no template on the Y chromosome that triggers a sexual response when Pamela Anderson enters the visual field, but there almost certainly are general predispositions that are a…
pharyngula | July 27, 2007We were just womping on the new president of the Texas State Board of Education for his foolishness about evolution, but it turns out he's got the all the symptoms of full wingnut syndrome: he's also a proponent of ignorance-only sex education.
It is strange that there's this whole suite of positions that would seem to be unrelated, but almost always seem to be adopted wholesale. If you know someone is against evolution, you can pretty much predict their positions on abortion, stem cells, the death penalty, education, GW Bush, and homosexuality. I wonder what common force ties all those…
pharyngula | July 22, 2007It must be funny pages day today—Doonesbury also gives us a good one that raises a good question about blastocysts.
I wish somebody could give a nice, coherent, sensible explanation of the reasoning on this one. We've got swarms of people — including good Christian people who want to be parents — going to fertility clinics and getting gametes extracted and put into a dish; this is considered, presumably a good thing by people who value procreation. These gametes are brought together to produce lots of zygotes, that in a typical fashion, begin their program of development and become…
pharyngula | July 16, 2007Ema finds a typical case of a newspaper article that mangles the whole idea of Plan B contraception. It's really not that hard to understand. Is it just that there are so many lies out there from the anti-family-planning mob that lazy journalists are easily confused?
pharyngula | July 14, 2007Did you know…
…that men never get abortions? If you aren't strong enough to have that baby, you've got no grounds to complain about male privilege.
…some of the instruments used in abortions are just like the ones used in transgender surgery?
…that every woman who gets an abortion would rather be taking a long romantic walk on the beach than be lying there with cold steel probing about in her nethers?
Pandagon has a whole collection of great arguments against abortion. Use them, and contribute your own!
And lest you think those are just too silly, here are some slogans from real…
pharyngula | July 13, 2007
If you've been reading that fascinating graphic novel, Y: The Last Man(amzn/b&n/abe/pwll), you know the premise: a mysterious disease has swept over the planet and bloodily killed every male mammal except two, a human named Yorick and a monkey named Ampersand. Substantial parts of it are biologically nearly impossible: the wide cross-species susceptibility, the near instantaneous lethality, and the simultaneity of its effect everywhere (there are also all kinds of weird correlations with other sort of magical putative causes, which may be red herrings). On the other hand, the…
pharyngula | July 11, 2007Leslee Unruh, witch-queen of the Dakotas, is in Minnesota for the National Abstinence Clearinghouse convention. Fortunately, we've got Jeff Fecke to document the atrocities. The question remains: who will fumigate and sterilize the Crowne Plaza Riverfront hotel afterwards?
grrlscientist | June 20, 2007tags: researchblogging.org, superb starling, Spreo superbus, Lamprotornis superbus, birds, behavior, infidelity
Superb starling, Lamprotornis (Spreo) superbus.
These small birds are commonly found in open woodlands and savannahs throughout Northeast Africa.
Image: Hogle Zoo, Utah.
While it is widely known that males of many species seek out extra-pair copulations in order to produce as many offspring as possible, the reasons for female "infidelity" are much more complex. For example, a study was recently published that showed how a bird species uses sexual politics to ensure maximal…
zooillogix | June 18, 2007Don't look at me, I'm hideously bloated!
Researchers at Ben-Gurion University in Negev, Israel, have identified whiteleg shrimp as the only known species where the male has a reproductive cycle or "period." The male whitelegs--actually a type of prawn--generate two sperm packets per month which they attach to their female mates during reproduction. If, however, these packets are not used, they can solidify and prevent the male from getting rid of them. Thus, these prawns have developed a period or cycle of every two weeks, whereby they lose their sperm packets and develop new ones.
Scientists…