The Caveman’s Corner

So this is probably all you’re going to get of my promised great series on anthropoid origins. Basically, I ran out of confidence that I could handle the material intelligently and am now out of time. So, I only got about two pages in to the Adapoid Theory. Just so that work isn’t a total waste, I’ll share it with you here. It’s unfinished obviously.

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I should really blog on other blogs more, because I read some things that I immediately admire a lot in some of the ones I frequent and that I think would benefit my two or three readers and the random people that find this site through a Google Images search for one of the pictures I’ve poached off somewhere else on the Internet, but get higher ranked on my site for some reason. Maybe because I label them better.

Anyway, I’ll start with this article I read on one of my favorites, John Hawks Anthropology Weblog, back on my birthday, June 18:

Don’t ask the experts if they can’t agree on the question

The post is about a conference convened as part of the World Science Festival to discuss “what it means to be human.” Predictably, most of the discussion centered around this trait or that trait, but as Dr. Hawks points out, no one trait can really include all humanity while excluding all other animals we wouldn’t call ‘human.’ What makes us human?

One thing is shared by all humans, and cannot be taken away: our evolutionary history. Each of us bears some — but none has all — of the marks of this history.

It is our history that connects us to our distant relatives, not our genes. Even with a close relative like a twentieth cousin, there is a decent likelihood that you will share no genes at all because of your shared kinship from your most recent common ancestor. By the fiftieth generation, it is a virtual certainty. You are a genetic stranger to your ancestors.

Within the span of fifty generations, a selected gene may completely transform a species, going from less than one percent to ubiquity. Indeed, a single genetic mutation may make you radically different from the rest of humanity, perhaps by restoring a thick coat of body fur, or making your tissues age at many times the average rate — both characters that some people would make part of the definition of “human.” Indeed, many such changes actually have happened in the past few thousand years.

Only history defines humanity, and will continue to define us no matter what we become in the future. We have not severed the genetic links between maize and teosinte, but they are tenuous enough to make the relationship difficult for the layman to see. We have intertwined several inbred strains, more than doubling grain production in a few decades. We regularly add genes from other organisms to our maize, subtly changing its phenotype. Yes, a good part of our corn now shares a history with Bacillus thuringiensis. But that does not deny its shared history with teosinte, or its unique history as a human domesticate. History is additive, inclusive — not subtractive.

Read the whole essay, it bears it.

The Anthropoid Origins series is taking longer than I anticipated, largely because I’m lazy and rediscovered Civilization IV there briefly (ironically, while taking a break from working on my paper on Adapoid Theory), which destroyed a few days of my life. I’ve also made a few false starts at blog posts that never ended up getting published. But, because I’m feeling guilty about neglecting my poor blog, I bring you a review of the book I just finished, Lucy’s Child: The Discovery a Human Ancestor.

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This is Meet an Ancestor installment three: Leptadapis magnus. The subject here also dovetails nicely with the post I’m writing on the adapoid theory of anthropoid origins, though it was selected a while before the idea for the latter series came into my head.

L. magnus cranium

Why is it relevant? Because L. magnus is an adapoid, specifically a member of the European family of the Adapidae. And that gives me the opportunity to tell an interesting story.

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Anthropoid origins is likely the single subject dearest to my heart in all of science, so I thought I might want to lay out in a series of essays for the reader some of the basic controversies surrounding this fascinating but much under-covered topic. I’d also like the sharpen up my own knowledge a bit as I fear it has been slipping. I’ll begin here by laying some of the basic concepts and terminology of the debate.

Anthropoid diversity

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According to G. Reagan and C. Ross in a study published in Folia Primatologica 71 and reported in the latest issue of Current Anthropology, twins of Wied’s black tufted ear marmosets share a significant amount of genetic information while in the womb. They’re chimeras.

To quote the report:

Starting on the nineteenth day of development and ending by the twenty-ninth, the placentas of twins begin to fuse. During this time, the twins exchange stem cells that carry with them their genetic makeup, with the result that individuals possess both cells inherited at conception that contain the original DNA of their parents and other cells that contain the DNA of their fraternal twins. This pattern, known as chimerism, was found in all bodily tissues sampled, including reproductive gametes. In one instance, a female marmoset passed on her twin brother’s DNA to her offspring, making her children her genetic nieces or nephews.

This has implications for the marmoset pattern of child rearing which involves extensive parental investment, especially by the father.

Because of the stem cell exchange between twins, individuals in a marmoset family group may share more than 50% of their genetic information (the typical degree of relatedness between parents and their offspring or between siblings). This creates a situation in which family members may have more invested in their offspring or siblings than predicted for other species—a possibility that will greatly affect the present understanding of how genetics and behavior interact.

Marmosets aren’t just their brother’s keeper. They’re their brother’s father.

After a long hiatus, I bring you another installment of “Meet a Contemporary.” Yayyyyy. School’s out now, so this blog should pick up a bit.

Meet Callitrhix (sometimes Cebuella) pygmaea, or the pygmy marmoset, a contender with the gray mouse lemur, lesser galago, and pygmy tarsier for smallest living primate. They’re cute little buggers and often kept in private homes as pets in the West (not a practice primatologists are favorable towards). For those two reasons, the pygmy marmoset might well be familiar to the reader.

Awww.

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Yet again, I’m contemplating embarking forth on a research project. Who knows how far this one will go, as my last… several… have died after I got overwhelmed by the preliminary reading. I do think this project has some distinct advantages, however: A) I now have access to the UT database at home on my computer, B) I can do this project without getting approval ahead of time (like with a zoo study), C) I won’t need too much math, I hope, and D) The study might be one that is fully within my resources to carry out.

What I was thinking of is a genealogical study to test the ‘Grandmother Hypothesis.’ For those not familiar, the grandmother hypothesis holds that the long human female post-reproductive lifespan evolved because grandmothers would aid their offspring in raising their children and thus increase their own reproductive success. Was this process active in recent societies? Well, to answer that, my plan is to examine genealogical records from Sevier and surrounding counties where I live. Fortunately, Appalachian people have a taste for this sort of thing, so genealogies aren’t excessively hard to come by. There are a lot of families with very long histories here as well that can be tracked back centuries in a single county. As for the specific methodology of analysis… I’ve found one other study of this type down in a Japanese city, and I’m planning to see how much I can apply from it. Any suggestions would be most welcome.

This is a concept that reading Dennison’s Nash A Little Anthropology, 3rd ed has acquainted me with, and its extremely interesting. I don’t believe I’ve ever specifically considered it before.

Such a stoic.

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I have a question I would like to ask the world:

?

What is this supposed to be? There is no monkey that looks like that. There is no animal on earth that looks like that. Why is this (basically) what everyone thinks of when they hear “monkey”?

As far as I can figure out, it looks sort of like a cartoony chimpanzee (Curious George maybe?) with a tail randomly stuck on. Not that chimpanzees are that color. There are some macaques that have vaguely that color of fur by they all have bright colorations on their exposed skin. There aren’t that many brown monkeys, honestly. Maybe a spider monkey except the proportions are all wrong.

I guess that’s what those are. Fracked up, brown spider monkeys. I want to get an ethnozoologist onto how on earth that’s come to be the number one public image of “primate.” *sigh*