Tag Archives: Evolutionary Biology

The Falsehoods

Biology is harder to learn than quantum physics. Why? Because most people think they totally get biology, but everyone knows nobody gets quantum physics. Therefore, any effort to explore quantum physics will result in new learning, but people rarely learn new biology. The bottom line is that our brains are full of biology, which would be good if most of it did not consist of falsehoods.
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The Natural Basis for Inequality of the Sexes

Is the Natural World a valid source of guidance for our behavior, morals, ethics, and other more mundane areas of thought such as how to build an airplane and what to eat for breakfast?1 When it comes to airplanes, you’d better be a servant to the rules of nature (such as gravity) or the airplane will go splat. When it comes to breakfast, it has been shown that knowing about our evolutionary history can be a more efficacious guide to good nutrition than the research employed by the FDA, but you can live without this approach and following FDA guidelines will not do you in. A naturalistic approach can work when it comes to behavior too, but there are consequences. You or someone you love would probably not like the consequences.
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The Science of Lion Prides


Although the paper addresses Tanzanian lions, this is a photograph of a Namibian lion
Starting some years ago, we began to hear about revisions of the standard models of lion behavioral biology coming out of Craig Packer’s research in the Serengeti. One of the most startling findings, first shown (if memory serves) as part of a dynamic optimization model and subsequently backed up with a lot of additional information, is the idea that lions do not benefit by living in a group with respect to hunting. They live in groups despite the fact that this sociality decreases hunting effectiveness. This is a classic case of “but wait, I can see it with my own eyes!” vs. data.

ResearchBlogging.orgSome of the most recent work done by Packer’s team has just been highlighted in a pretty nice write up by Mattt Walker in the BBC, representing a paper just coming out. The most interesting finding: Male lions kill (or attempt to kill) females from neighboring prides in order that their own pride obtains numerical superiority in pursuit of territorial competition.
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BBC: DNA mutations followed by selection does not lead to new species!?!?

In an BBC article describing a Royal Society paper on the rate of mutation in warm vs. cooler climates, the BBC made this statement:

DNA can mutate and change imperceptibly every time a cell divides and makes a copy of itself.

But when one of these mutations causes a change that is advantageous for the animal – for example, rendering it resistant to a particular disease – it is often “selected for”, or passed down to the next few generations of that same species.

Such changes, which create differences within a population but do not give rise to new species, are known as “microevolution”.

I suppose the BBC is into the Hopeful Monster theory or something.

Read it here, come back, and fight it out.

Ultimate Causes, Proximate Mechanisms

Why does a soldier throw himself on a hand grenade to save the lives of a half-dozen unrelated fellow soldiers? Why does someone run into a burning building they happen to be passing to save a child they don’t know? From a Darwinian perspective these seem to be enigmatic behaviors that would “select against” such individuals (or more properly, select against the heritable component of this behavior).

There are several possible explanations for this….
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More emotional intelligence = more orgasms

ResearchBlogging.orgAccording to a study just coming out in the Journal of Sexual Medicine, “variations in emotional intelligence–the ability to identify and manage emotions of one’s self and others–are associated with orgasmic frequency during intercourse and masturbation.”

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Grasping the function of the human penis

Gallup has taken on the task of explaining, in ultimate terms, the evolutionarily designed features of the human penis. He works this as an engineering problem from the perspective of evolutionary psychology, which is always a little bit dangerious, but gallup isn’t quite the arm waiver that a lot of other EP’s are, so he may be doing it right.

Gallup’s work is written up an an all-too-sophomoric Scientific American article by Jesse Bering which just barely falls short of explaining this important biological phenomenon in terms of a pair of headlights, a flashlight, and a little red waagon.

Here’s the money quote:

Magnetic imaging studies of heterosexual couples having sex reveal that, during coitus, the typical penis completely expands and occupies the vaginal tract, and with full penetration can even reach the woman’s cervix and lift her uterus. This combined with the fact that human ejaculate is expelled with great force and considerable distance (up to two feet if not contained), suggests that men are designed to release sperm into the uppermost portion of the vagina possible. Thus… “A longer penis would not only have been an advantage for leaving semen in a less accessible part of the vagina, but by filling and expanding the vagina it also would aid and abet the displacement of semen left by other males as a means of maximizing the likelihood of paternity.”

The other component of the work is the intriguing possibility that penises have evolved to carry semen previously left in one female’s vagina from another male to be deposited hours later in the vagina of a second female. Which I suppose could be called facilitated cuckoldry.

I’ve not read the original paper yet. I’m not quite up to it. But if I do, I’ll let you know if it is truly a seminal work, or if Gallup is just jerking us around.

The writeup is here.

Where have all the ducklings gone??

Or, more exactly, where are they all going to go during the next two or three months?

I’m sitting here between a large frozen lake and a small “pond” (connected to the lake with a channel) that has patches of open water on it. (The melting on the pond is probably because the bioactivity at the bottom of the pond increases water temperature.) There is a pair of mallards on the pond, and I expect that in a few weeks there will be two or three mallards and three or for mergansers, all females, and each with between six and 12 or so ducklings. These 60 ducklings will initially hang out only with their mothers, but as time goes by the mothers will overlap their feeding territories and night time roosts, and the ducklings will start to form a creche. It is even possible for a multispecies creche to form.
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Finches Determine Sex of Offspring

As you know if you read my blog, Trivers Willard is an important theoretical construct which has been tested numerous times. TW works in some species, not in others, and overall, that should be predictable (accroding to TW).

It turns out that finches control the sex of their offspring, and do so in a way that TW would predict, apparently. There is a paper in Science that I’ll probably eventually get to writing up for you, and in the mean time, here’s a quick news report from Scientific American.

See if you can figure out how Trivers Willard is working here, and why the important theoretical aspect of this research is glossed in this news report.

A dead gene comes back to life in humans

ResearchBlogging.orgWhy is there “junk DNA”? What is Junk DNA? What is a Pseudogene? What is Gene Duplication?

Goodness, you certainly do have a lot of questions. And some of them can be answered, or at least addressed, on examination of a very interesting new paper recently published about a gene that became a useless “pseudogene” a very long time ago and has recently been revived by evolution to serve once again as an active member of the community we know of as the genome. In humans.
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