Monthly Archives: February 2009

Male vs. Female Brains

The male and female human brains are different. Some of the better documented differences are similar to differences seen in other mammals. They are hard to find, very small, and may or may not be of great significance. Obviously, some are very important because they probably relate to such things as the ability … or lack thereof … to bear offspring. But this is hardly ever considered in the parodies we see of these differences.

[Repost from Gregladen.com]
Continue reading Male vs. Female Brains

Topi or not Topi …

i-e1003b13638050040bea14fa3d3fabe0-repost.jpgGo 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 African antelope Damaliscus lunatus (a.k.a. “topi”) explores this possibility.

Continue reading Topi or not Topi …

Midori’s Floating World Cafe

Lizzie, got a job. It’s a pretty nice job, with benefits and a salary and everything. Not in her field (biology), but it is a job she likes. So I took her out for a congratulatory dinner, which ultimately gave me a chance to try a new restaurant. Also, we had been in a routine for a few months of meeting almost every week to work on a project, and those meetings had stopped due to scheduling issues (like, that she went and got a job …). It was time for another dose.

… continued …

Coleman Goof

So Ana IM’s me, and I can tell through the text that she was almost out of breath with excitement or fear or something. But then I remembered shes been observing the Minnesota Senate court challenge. Turns out something rather interesting happened. Luckily, TPM has it covered:

Norm Coleman’s lawyers just had a very awkward moment in court, in their attempt to prove that absentee ballots were double-counted — it turns out they’ve failed to share evidence with the Franken camp, involving a key witness.

The Coleman camp called Pamela Howell, a Republican election worker in Minneapolis, who said she heard another election judge exclaim that they had forgotten to properly label duplicates of absentee ballots that had been too damaged for the machines to count. She also said she did not recall whether they had made a note of this in the precinct incident logs.

Franken lawyer David Lillehaug then got up, setting out to impugn Howell as an unreliable, partisan witness. She admitted that she called up Coleman’s legal team during the recount, …

Holy crap, more here. TU Ana.

First it was bear paternity tests, now it is volcano monitoring

When will the madness end? When the Republicans dry up and blow away, of course.

In the Republican response to Obama’s State of the Union 2.0 address, by Bobby Jindal, governer of Louisiana, we heard this:

“Instead of monitoring volcanoes, what Congress should be monitoring is the eruption of spending in Washington, D.C.,”

The reason why volcanoes have been picked out of some speech writer’s anal sphincter zone is because they erupt and they wanted the metaphor. Or because Jindal believes he has no volcanoes in his state (but he would be wrong) or because of some other rhetorical reason. This is the same exact device as the bear paternity test complaint we heard spewing forth from the Hypocrite McCain and the Moron Palin during the campaign.

Maria Brumm is talking about it: “Something Called Volcano Monitoring”: Bobby Jindal Needs a Geology Lesson

Do Republicans (or moderates who don’t have a kneejerk anti-Republican reflex) also feel like he’s talking to the nation as though we were all kindergarteners? I was flabbergasted, but I don’t know how to properly account for my rather strong political biases here.

Scientific American is talking about it: Bobby Jindal and volcano monitoring: What was he talking about?

“Why does Bobby Jindal think monitoring volcanoes is a bad thing for the government to be doing?” Nick Baumann writes in Mother Jones. “There doesn’t seem to be any immediate way for private enterprise to profit from monitoring volcanoes (maybe selling volcano insurance?), but there is obviously a huge public benefit from making sure volcanoes are monitored: warning people if a volcano is going to erupt. Isn’t that obvious?”

OK, so clearly the Republicans are mean spirited knowledge-free hypocrites and Jindal is therefore a great spokesperson (or should I say spokesman) for them. And Maria and Sciam are right. But everyone is missing the true irony here.

The true irony is this: Remember New Orleans? Remember Katrina? Scientific research on disaster prediction predicted Katrina and its effects on New Orleans perfectly. PERFECTLY I SAY!!!! But those predictions were ignored (and continue to be ingnored).

But scientific monitoring does not always get ignored. The roads are laid out in many places with consideration for evacuation in the case of certain events. As Maria pointed out, large numbers of lives and dollars were saved from the effects of the eruption of Mt. Pinatubo … which was a (say it with me now) a volcano … Because. Of. Scientific. Monitoring. And so on. Katrina is seen as an immeasurably large disaster of public policy because the clear warnings from the scientific research were ignored. Had they not been ignored, we would not be talking about this.

Teh Irony, then, is that the biggest disaster happened in the most third world of the states because of the boobs that run that place, and Bobby Jindal is Head Boob. And he is telling us what we need to do regarding scientific monitoring of potential natural disasters.

The metaphors! They are everywhere!

The fox is giving us a lesson on how to close the chicken coop. The farmer who left the barn door open is telling us about how to take care of your horses. The pot is explaining to the kettle how to clean off the soot. Chicken little is giving us a lesson on framing. The little Dutch boy is taking piano lessons. The Republican is telling us how to manage scientific priorities.

Oh, no, wait, that last one is not a metaphor. It is a TRAGEDY!!!!

Chimpanzee Food Sharing

Is chimpanzee food sharing an example of food for sex?

i-3691706735948748b5a89f0a306951ac-chimp_share_tree.jpg
One of the most important transitions in human evolution may have been the incorporation of regular food sharing into the day to day ecology of our species or our ancestors. Although this has been recognized as potentially significant for some time, it was probably the Africanist archaeologist Glynn Isaac who impressed on the academic community the importance of the origins of food sharing as a key evolutionary moment. At that time, food sharing among apes was thought to be very rare, outside of mother-infant dyads. Further research has shown that it is in fact rare … the vast majority of calories consumed by human foragers in certain societies and at certain times of the year comes from a sharing system, while the fast majority of calories consumed by chimpanzees is hand to mouth without sharing.
Continue reading Chimpanzee Food Sharing

Marta’s (good) questions, … fur

Why did humans evolve hairlessness? Hair (fur) protects mammals from heat and cold, what would be the benefit from losing this asset?

I think the most commonly held theory is that fur works on quadrupeds, but once you stand upright, it is less effective, and less fur works better. For later time periods, clothing works better than fur because it is more adaptable. Consider that whatever fur-based system human ancestors had was based on needs in the tropics where it does not get that cold, so it is not hard to imagine that clothing is much more effective.

Recent studies of body parasites suggest that body lice unique to humans differentiated genetically only fairly recently, in the range of several tens of thousands of years. This body lice requires clothing … human clothing on human bodies is the habitat for these lice. This suggests there may have been a reduction from a certain level of furriness only with modern humans living in a wide range of environments and using controlled fire, clothing, and some kind of shelter (hut/house) to deal with the elements. So it is possible that the immediate ancestors to modern humans (perhaps Homo erectus?) were actually fairly furry.

As for details of the body hair, this is also interesting. Why do humans have pubic hair but not a lot of other hair? Why to males have more body hair than females in many cases? Why to human males have facial hair? The African Apes have much less facial hair than most modern human males. It has been suggested that this has to do with sexual selection. It is important to distinguish between the idea that the starting condition is a lot of fur and that females may have lost more than males, vs. the starting condition was very little hair and males have added more. The amount of fur, it’s appearance, etc. may be related to testosterone (this is true in males and females but more obvious in males) so facial hair may be a signal of “quality” in males.

Marta’s (good) questions, … continued


Why did the evolution of a large brain happen only once (among mammals, and in particular, primates?)

Larger brains have evolved a number of times. It seems that there has been a trend over several tens of millions of years of evolution of larger brains in various clades, such as carnivores and primates. There is probably a kind of arms race going on among various species in which a larger brain is an asset.

However, as you imply, a really large brain (like the extraordinarily large human brain) seems to be very rare. One of the reasons for this is that there are at least two major kinds of costs of a large brain that outweigh the benefits. One kind of cost is the energetic expense of having this large brain. Over 10% of the day to day energy demands of an adult human go to the brain. The total energy requirement of an infant can be over 60% while the brain is both a relatively large proportion of the infant’s body, and is undergoing a great deal of growth. The brain tissue is very picky about things like the temperature it requires for normal function and the kind of nutrient it needs.

Continue reading Marta’s (good) questions, … continued

Marta’s (good) questions, Greg’s (oft’ lame) answers: Bonobos?

My student, Marta, exploded the other day.

She was sitting there in class two weeks ago and exploded. She does not know that I know this, but I noticed it happen. Since she was sitting, as usual, in the front row, and it was all in her face, the other students did not see it but I definitely did.

By “exploding” in this case I mean that her brain suddenly filled with unanswered questions, which she then started sending me in frantic emails. Many of these questions are about things we will eventually get to in class, but some are on issues that we won’t touch on at all. I decided, and I received her kind permission to do this, to answer her questions by blogging them. This way I get to kill two birds with one stone, which is usually a good thing (unless of course you are the second bird).

In some cases I’ve re-written the question a little, but in all cases, they are good questions. I cannot guarantee that all of my answers will be good. But I do appreciate Marta’s inspiration, and find it inspiring myself. My only concern is that Marta gets interested enough in this material to become a biological anthropologist and thus wastes an otherwise potentially productive life. I’m hoping she becomes a doctor or a world leader instead, but we’ll see…

OK, on to the first question (I’ll deal with others in later posts):
Continue reading Marta’s (good) questions, Greg’s (oft’ lame) answers: Bonobos?

The Recluse Spider Warnings

It is almost Spring in the Northern Hemisphere. One thing this means that US citizens and I’d bet some Canadians will be receiving the annual Brown Recluse Spider Warnings via Email. In order to reduce the negative effects of this email spamish meme, I hereby inoculate you. If you get the email, which usually comes with dire warnings and lots of photographs of bad things happening to people’s flesh allegedly because of a recluse spider bite, just delete it.

Look at this map and read the caption:
i-ef75aa1524c60120505cfa8198fd8495-colorloxmap.jpg

This map is based on data collected by arachnologists and is provided courtesy of Rick Vetter. Generally, recluses can be expected to be uncommon at the margins of this range. Rarely, they are found outside of this normal distribution in very localized areas. Such rare encounters should not be interpreted as a broadening of the species typical range or as an indication of large populations throughout the area in which the unusual sighting was recorded.

The recluse spider packs a nasty bite, but is not as common or widespread as the email you receive will suggest, and it is not as dangerous either. The Brown Recluse Spider Project has more.