behavioral biology
gregladen | December 17, 2007
Every few years a paper comes out "explaining" short stature in one or more Pygmy groups. Most of the time the new work ads new information and new ideas but fails to be convincing. This is the case with the recent PNAS paper by Migliano et al.
From the abstract:
Explanations for the evolution of human pygmies continue to be a matter of controversy, recently fueled by the disagreements surrounding the interpretation of the fossil hominin Homo floresiensis. Traditional hypotheses assume that the small body size of human pygmies is an adaptation to special challenges, such as…
gregladen | December 17, 2007Prawns (shrimp) behavior is exploited by sticklebacks in the quest for food.
The fish ...
... use prawns to determine the best place to be. Prawns, it seems however, don't have the same aptitude to use the sticklebacks for their advantage
[According to researcher] Paul Hart, "It is a common experience for most of us to look at what other people are doing when we ourselves are not sure of what to do next. One of the benefits of being a social species is that we can tap into the expertise of our fellow humans to improve our own chances of success when circumstances are uncertain. Many would…
gregladen | December 16, 2007
Every few years a paper comes out "explaining" short stature in one or more Pygmy groups. Most of the time the new work ads new information and new ideas but fails to be convincing. This is the case with the recent PNAS paper by Migliano et al.
From the abstract:
Every few years a paper comes out "explaining" short stature in one or more Pygmy groups. Most of the time the new work ads new information and new ideas but fails to be convincing. This is the case with the recent PNAS paper by Migliano et al.
From the abstract:
Explanations for the evolution of human pygmies continue to be a…
gregladen | December 11, 2007There seems to be some interesting things going on with the recently reported study of rates of evolution in humans. We are getting reports of a wide range of rather startling conclusions being touted by the researchers who wrote this paper. These conclusions typically come from press releases, and then are regurgitated by press outlets, then read and reported by bloggers, and so on. Here is, in toto, the press release from the University of Wisconsin, where John Hawks, one of the authors of the study, works. I reproduce the press release here without further comment.
Genome study places…
gregladen | December 6, 2007Hey, there's a fight over at Sandwalk. PZ and Larry are going at it as to how good, or bad, this video is:
Click To Play
I'm on the fence. I think it is not true that all genes are switches. Some of them code for structural proteins, for instance. Thousands of genes code for neurotransmitters. There are many genes that are producing products on a regular basis in adult cells that you can't live without.
On the other hand, the video does a good job at explaining the evo devo part of the equation.
I do not like the playing dumb bit in the beginning. Hey, if you don't know that "evo…
gregladen | December 4, 2007Go to any bar and you'll see a lot of males standing and sitting around not mating. I'll bet you would have guessed that the reason they are not mating is that no females will mate with them for one reason or another. But there is the distinct possibility that they are very inconspicuously resisting mating opportunities. It turns out that males can do this .... avoid mating without conspicuous resistance ... more easily than females. For obvious reasons.
This could be why what has become (inappropriately) known as "reversed sexual aggression" often goes unnoticed, and a recent study of the…
gregladen | November 27, 2007Genes determine basic behavior, like the behavior associated with being a predator. Or avoiding being eaten by a predator. This we know to be true because millions, zillions, of years of evolution must have shaped genes ... especially in mammals with with their whopping big brains and all ... to have genetically coded behaviors.http://www.bloggingwv.com/love-everybody-even-the-squirrelly-ones/
Or, perhaps not. Perhaps we need a slightly different view of behavioral genetics. (click on the picture to see the whole story..)
gregladen | November 25, 2007According to a story in the last issue of Psychological Science:
... for most women, high sex drive is associated with increased sexual attraction to both men and women. For men, however, high sex drive is associated with increased sexual attraction to only one sex or the other, depending on the individual's sexual orientation. These results suggest that the correlates of sex drive and the organization of sexual orientation are different for women and men.
[This is a repost from Gregladen.com]
This is one of those studies where a perfectly good (i.e., falsifiable) hypothesis was being tested…
gregladen | November 12, 2007I find it absolutely fascinating that scientists often bother to estimate the effects of diet by feeding controlled quantities of food, especially plant food, to rats to see what happens.
For example, there is a common substance in cooked food that, if fed in even modest quantity to rats, causes the rats to get cancer and die in no time. This raises concerns for humans because, well, the rats died. So the substance must be "bad for you."
But this approach to nutritional science, and the reasoning that goes with it, is deeply flawed.
Now, you may wish to jump in and say, "No, wait,…
gregladen | November 7, 2007[Reposted without revision from gregladen.com]
This is obviously true, and i've been saying this for a long time. And I'm not talking about the butt-slaps and sharing chewing tobacco and stuff.
To a certain extent, digit ratios seem to be a reasonable indicator of the kinds of hormonal environment in which a person develops in utero. It turns out that the indicator of homosexuality is the same as the indicator of athleticism, only turned up even more. In other words, a certain kind of hormonal environment in which a male fetuses develops can result in a higher likelihood of that person…
gregladen | November 6, 2007A new species of peccary has been discovered in the Amazon. It's different from other peccaries in that it appears to be a frugivore. It also lives in pairs or very small family groups. This is, of course, exactly what one might expect. Frugovores eat high quality food, while the other peccaries eat lower quality food. Higher quality food is rare and dispersed so it is difficult to get into larger groups.
A huge, undiscovered animal lurking in the Amazon rain forest? When pigs fly, you might say.
But recently, Dutch biologist Marc van Roosmalen spotted a new species of peccary--a type…