Life Sciences
clock | June 11, 2006After three lectures on the basics, a long lecture on diversity, and a hard first exam, it is time to turn our attention to anatomy and physiology for the rest of the course:
Anatomy is the subdiscipline of biology that studies the structure of the body. It describes (and labels in Latin) the morphology of the body: shape, size, color and position of various body parts, with particular attention to the internal organs, as visible by the naked eye. Histology is a subset of anatomy that describes what can be seen only under the misroscope: how cells are organized into tissues and tissues into…
grrlscientist | June 10, 2006This week's question from the mothership is a fantasy-type of question.
Question: Assuming that time and money were not obstacles, what area of scientific research, outside of your own discipline, would you most like to explore? Why?
There are several avenues of research that appeal to me, all of which are "cutting edge" fields that of course, are quite exciting.
First, I would love to study avian influenza viruses, which I think are utterly fascinating. I would be especially interested to research the evolution of lethality in these viruses and identifying which molecular changes are…
pharyngula | June 10, 2006
To continue a bit of theme, I mentioned that there were some different ways to approach biology, and that old-school systematists with their breadth of knowledge about the diversity of life are getting harder and harder to find. This is something I also bring up in my introductory biology course, where we discuss how biologists do their work, and I mention that one distinction you can find (which is really a continuum and frequently breached) is that there are bench scientists and field scientists, and they differ in multiple ways. Bench scientists tend to be strongly reductionist, tend to…
evolvingthoughts | June 9, 2006
Suppose you come from Mars, freshly minted with your PhD degree in the ethology of terrestrial mammals, and you decide to study this ape species that uses language and technology. Suppose further it's about 10,000 years before now. What would you describe? That is the topic of this post.
It's not the first time the "anthropologist from Mars" gambit has been used. Alfred Russel Wallace, who I suspect had some form of Asperberger's, described himself that way, and of course Oliver Sachs, who obviously does, did so too. I have spent my life thinking that somehow I was inserted by accident…
tsmith | June 9, 2006Over at Doc Around the Clock, Dr. IBear has a nice post on Lyme disease: what it is, what it's not, and how to deal with ticks (appropriately, not as his mom removed them). He mentions this:
Most of the time people who get Lyme disease don't even know or remember being bitten by a tick. Thus, it stands to reason that if you do remember being bitten by a tick you probably don't have Lyme disease.
I want to elaborate on this just a bit, below.
A reason many people don't realize they've been bitten is because when the tick bites the human to transmit the Borrelia spirochete, it's not always a…
pharyngula | June 8, 2006
Creationists are fond of the "it can't happen" argument: they like to point to things like the complexity of the eye or intricate cell lineages and invent bogus rules like "irreducible complexity" so they can claim evolution is impossible. In particular, it's easy for them to take any single organism in isolation and go oooh, aaah over its elaborate detail, and then segue into the argument from personal incredulity.
Two things, one natural and one artificial, help them do this. Organisms are incredibly complicated, there is no denying it. This should be no solace to the anti-evolutionists,…
tsmith | June 5, 2006Liam Scheff has now turned his attention from HIV to avian influenza, with predictable results. Analysis below...
Scheff's self-stated goal is to "...review some of the bright and shiny inconsistencies that have come into view on the bird flu." However, he's not exactly consistent himself, ranging from minor errors to total contradictions of his own words. He starts off discussing "stray cats and Chinamen:"
In March, 2006, The Associated Press reported: "In Austria, state authorities said Monday that three cats have tested positive for the deadly strain of bird flu in the country's…
tsmith | May 31, 2006 It can't be said often enough that "nothing in biology makes sense except in the light of evolution." Moving from physical characteristics--color, bone shape, the form of bacterial cells--to genetic characteristics in order to classify organisms--and infer phylogenies--was a giant advance. That the molecular characteristics confirmed what was known using physical characteristics was a breakthrough, and allowed for more sophisticated analyses of organisms that don't have bones or other easily-observable physical features that allow for simple classification into groups: microbes. I've…
grrlscientist | May 30, 2006
Black-throated green warbler, Dendroica virens.
Image appears here with the kind permission of the photographer, Pamela Wells.
Click image for larger view in its own window.
Birds in Science
Wendy Reed and her research team's study found that male dark-eyed juncos, Junco hyemalis, with extra testosterone were more attractive to females and produced more -- but smaller -- offspring. Smaller offspring had lower survival rates than larger offspring. The extra testosterone also made the male birds sing more sweetly and fly farther. The testosterone-laden birds proved irresistible to older,…
loom | May 29, 2006Usually when you hear about the rapid evolution of bacteria, the story is typically some grim tale of antibiotic resistance or the emergence of some pathogen once restricted to animals. Here's a nicer narrative, but no less instructive. In tomorrow's New York Times I have an article about yogurt, and how the bacteria in its culture have been undergoing drastic genomic change since the stuff was invented some 5000 years ago.
I report on a new study on Lactobacillus bulgaricus, found in many yogurt cultures. (The paper comes out some time this week in PNAS.) The analysis, based on the microbe's…
pharyngula | May 28, 2006On a warm and lazy holiday afternoon, determined to avoid any exertion and relax in my easy chair, I was contemplating something easy on the brain: beauty. I have no idea what makes something beautiful, but I could at least approach the subject empirically and catalog those things and experiences the I have found beautiful…so I put together a list. It's nothing definitive, it's merely personal, a set of memories of moments where I have been awestruck with beauty.
The zebrafish embryo. These tiny little embryos encapsulate everything that's lovely about development and biology. They are…
jlynch | May 26, 2006About twenty-five years ago, I read Gerald Durrell's book My Family and Other Animals (1957), an account of his early life in Corfu. One part made a distinct impression on me - his account of watching geckos on the walls of his house. To me, as a teenager in Ireland, this was the height of the exotic, after all Ireland has only one type of native reptile, the Common Lizard, Lacerta vivipara, and I had only seen one on a single occasion (slow worms, Anguis fragilis, are a recent localized introduction). To the twelve-year old me (in wet, cloudy, overcast Ireland), Durrell's experience of sun…
tsmith | May 22, 2006 Razib mentioned here an article in the Boston Globe "which profiles researchers who suggest that variation in gut flora (the mix of bacteria) might be the cause of differences in body weight." The comments are somewhat skeptical, and I started to write a comment on the topic but it became a bit unweildly--so I've added it below instead.
As I've discussed previously, figuring out the relative contributions of environment versus genetics in obesity isn't an easy feat. As with so many human diseases/conditions, the "cause" is certainly multi-factorial. It's pretty clear that the genetics…
grrlscientist | May 22, 2006
Nesting Pacific loon, Gavia pacifica.
Photograph by PicsMan.
Birds in Science
Two carefully planned sets of experiments to be published on Friday in the top-tier peer-reviewed journal, Science, show intelligent birds and great apes can plan into the future in a way that transcends simple food caching, as squirrels, foxes and other animals do. "Together with recent evidence from scrub jays, our results suggest that future planning is not a uniquely human ability, thus contradicting the notion that it emerged in hominids only within the past 2.5 to 1.6 million years," wrote Nicholas Mulcahy…
tlambert | May 21, 2006The Washington Post reveals that Roy Spencer is the man behind environmentalist parody site ecoEnquirer.com:
Somewhere in an office about 600 miles southwest of here, former NASA scientist Roy W. Spencer is laughing. The 50-year-old, white-haired PhD dreamed up the spoof site -- sort of the Onion meets the Weather Channel -- because he thinks people are overreacting to the threat of climate change.
Now a principal research scientist at the University of Alabama at Huntsville, Spencer says human activities have "likely" contributed to climate change, but he argues that "since we do not…
pharyngula | May 21, 2006There is no more reverent way to wake to a fine Sunday morning than to discover another religious zealot punching himself in the face. Repeatedly. The Rabbi Avi Shafran is waxing indignant in a syndicated article that is popping up all over the place, in which he tries to denounce Zizek's most excellent article on the virtues of atheism. The best he can do, though, is whimper at length that atheists are just plain bad people—it's an argument to appeal to bigots who already have a prejudiced view of those who don't share their religion, but it's not very persuasive to people who can think.
It…
tsmith | May 17, 2006When I was in school, I was taught about the 5 kingdoms of life: Monera (all bacteria), and the eukaryotes: Protista, Fungi, Plantae, and Animalia. Since that time, there's been a bit of a change in the organization. This is largely due to investigation of the Archaea (sometimes still referred to as "archaebacteria"). It was recognized that these organisms were so unlike bacteria (and of course, unlike the eukaryotes) that they deserved their own grouping. Therefore, the most common strategy currently employs 3 domains of cellular life at a level above the kingdom: Bacteria,…
loom | May 17, 2006Nothing gets the blood boiling like a manimal. For many people, the idea of breaching the human species barrier--to mingle our biology with that of an animal--seems like a supreme affront to the moral order. In his January state of the union address, President Bush called for a ban on "creating human-animal hybrids."
These so-called chimeras, according to their opponents, devalue humanity by breaching our species barrier. "Human life is a gift from our creator, and that gift should never be discarded, devalued or put up for sale," Bush declared. Senator Sam Brownback of Kansas expanded on…
grrlscientist | May 15, 2006
Orange-bellied parrot, Neophema chrysogaster,
now numbering only approximately 200 individuals, is one of the world's rarest birds.
Photographer: Dave Watts.
Birds in Science
Scientists have discovered that migrating dragonflies and songbirds exhibit many of the same behaviors, suggesting the rules that govern such long-distance travel may be simpler and more ancient than was once thought. This research is based on data generated by tracking 14 green darner dragonflies with radio transmitters weighing only 300 milligrams -- about a third as much as a paper clip. Green darners, Anax…
razib | May 14, 2006Seeing as this is Mother's Day, I want to point to this working paper, Menopause and post-generative longevity: Testing the 'stopping-early' and 'grandmother' hypotheses. It is a 44 page review of a lot of literature that is out there. The short of it is that menopause is something of a mystery, our nearest relatives, the chimps, seem to be rather normal animals in that the female reproductive lifespan is coterminus with the whole of her life after sexual maturation. In contrast, human females engage in a proactive "shut down" of reproductive capacity. Not only that, after menopause they…