Introduction

For the last day and a half I have been attending the Sacker Colloquium entitled In the Light of Evolution IV: The Human Condition. Overall, it has been quite interesting, despite some disappointing talks. I intend with this post to briefly describe some of the more interesting talks that have occurred.

Opening Talk — E. O. Wilson

The opening talk of the colloquium was given by E. O. Wilson, mainly regarding the 4 great books of Darwin. The most distinctive claim he made — in addition to numerous anecdotes and facts about Darwin and other things — was that biological knowledge is now firm enough to be called a body of laws. In particular, he had in mind first that biological processes are all subject to the laws of physics and chemistry, and second that diversity and processes are the result of natural selection. While I do not know nearly enough biology to comment on the correctness of these principles, they do seem to make a lot of sense. Unfortunately (though perhaps by design) the talk did not present detailed evidence for the claims. The more important thing, however, is the directional proposal he presented. That is, he promoted focus on the question of the reason for the rarity of transitions.

An Introduction to Hominin Evolution — Bernard Wood

Bernard Wood gave an interesting talk that highlighted some of the potential pitfalls in hominin(e) taxonomy that I had not previously considered. Specifically, he was concerned about the importance of extinct branches of the tree of life for placing fossils. One such example that was recently discovered was ar. ramidus. This fossil was billed as the most recent discovered common ancestor of chimpanzees and humans, but there are other things to consider. That is, there is definitive reason to place ramidus as a direct ancestor to modern humans as opposed to on a branch that left the directly ancestral track between the chimp/human split. The point of the talk was to support a more detailed study of morphology in taxonomy.

Peopling the Planet Out of Africa — Doug Wallace

In an attempt to provide a comprehensive story of what drives the evolution of biological complexity, Doug Wallace presented a story based on energy. Drawing a parallel with thermodynamics and the natural decay of complexity in the absence of energy flux, he presented a view where biological adaptation was focused on aspects of energy acquisition and use. Biological niches are basically adaptations to caches of energy, regional adaptations are adaptations to energy distribution, and individual adaptations are in response to local energy variations. In order to support this, he focused on the role of mitochondria and mitochondrial DNA. The major tool for differing scales of adaptation, he argued, were the rapid mutation of mitochondrial DNA. I wish I could provide more details of this talk, but it was very technical and very fast.

Modern Human Evolutionary History in Africa — Sarah Tishkoff

Another interesting talk regarded the application of genetic tools to understanding human history. Sarah Tishkoff presented work she was involved in regarding this, especially with regard to identifying genetic differences in groups across Africa. In particular, she focused on the history of lactose tolerance/intolerance in various sub-populations. Through a variety of techniques, she was able to identify three separate developments of mutations promoting lactose tolerance, two of which are distinct from the mutations promoting lactose tolerance in Northern European populations. The ability to identify the coevolution and spread of these genetic features was fascinating.

Population Genetic Inference in the Personal Genome Era — Carlos Bustamante

Though this was yet another very technical talk for which I do not have a proper background to relate in detail, Carlos Bustamante presented some work which was still fascinating even in a broad-strokes picture. His work was an attempt to derive historical details from individual genetics. One particularly interesting (and scary) application was the ability to identify very reliably the country of origin in Europe of someone (even within as little as 200 miles) given their genetic heritage. The basic tool for this was Principle Component analyses, but it did sound like he and his collaborators had developed some even more effective tools for similar analyses. As I said before, this was quite interesting, but also very scary in a Gattaca sort of way.

Uniquely Human Changes in Sialic Acid Biology — Ajit Varki

The second of the talks on the second day of the conference was, in my opinion, quite awesome. Ajit Varki presented work of him and various collaborators regarding an evolutionary picture of human genetics and immunology. Apparently, there are two common markers for cells in various organisms — Neu5Ac and Neu5Gc. Humans, unlike chimpanzees and most other organisms no longer exhibit Neu5Gc. However, it was this that allowed self-cells to be readily identified. Without it, many pathogens became more effective at impersonating self-cells. So the human body developed other means for identifying pathogens through marking Neu5Gc, which many still contain. But human cells are also capable of “eating” Neu5Gc, which is present in many red meat and milk products.

Moreover, the identification and eradication mechanisms based on Neu5Gc also seem to be connected with a wide variety of chronic disorders, including autoimmune diseases, cancers, and many more. This seems to be a very important discovery, and I would love to read more about it.

There are three more talks to come yet this afternoon, so I may be posting an update later today if they seem worth mentioning.

Rousseau’s Social Contract

Over the weekend I began reading Rousseau’s On the Social Contract so as to get a better idea of what it was from the horse’s mouth. Though I have only gotten through Book 1 so far, it is clear not only how important the work must have been at the time and how it influenced American democracy, but also why such interesting connections have been made between it at evolutionary game theory. Skyrms has two books (that are very fun and easy reads) that draw out the beginnings of these quite interesting connections.

In general the connections are thus (as I see it so far). The social contract is a cooperation of people to give up some rights for the greater good. However, this cooperation prima facie seems to be irrational, since any one person could do better by pretending to follow the rules of society, but really pursuing their own ends exclusively. Skyrms does an excellent job of illuminating how this, and other problems may be resolved by understanding the development of necessary features of the social contract such as stable cooperation in game-theoretic terms. The use of evolutionary game theory instead of more economics-y one-shot interaction game theory lends weight to the emergence of a social contract and its stability instead of just its possibility as well.

Philosophy of Biology

For something (almost) completely different, I will now turn to some philosophy of biology and mind stuff. Over the weekend, I had something of a small epiphany about what might get me to a paper for the evolution of cognition seminar I am taking. This started a week ago when, towards the end of a presentation about the last chapter and overall plan of Tomasello’s The Cultural Origins of Human Cognition I got hit with an unexpected¹ “So what?” question that I deflected.

Doing the reading for this week, I realised that the content was interesting, but it didn’t seem to have much obvious philosophical punch. Most of the readings were concerned with evidence for/against or standards for determining whether human cognition evolved. This seemed very strange when I tried to consider the alternatives. It seems that the answer is clearly yes, or alternatively a rejection of evolutionary theory generally². So I started asking myself why exactly we were reading it. The response I came up with — which is actually a bigger, but more correct question — was related to the fall seminar with the same professor and the colloquium talk last Friday: If evolution did evolve, then so what?

I don’t have a good answer to that question yet, but at least focusing on it seems to be a good place to look for paper topics. I only wish something like this had occurred to me in the fall so I could have attempted to write a paper for the evolution of morality class and gotten my ethics requirement out of the way then.

Non-Philosophy

On some things even more completely different, this weekend my bicycle was stolen, and I survived my first sensible earthquake last night. C’est la vie.

¹ The lack of expectation was probably poor planning on my part.

² That statement is probably wrong, but it doesn’t appear to be wrong in an interesting enough way to fix it.

Taking a break from my Carnap streak for at least a day, I intend to give an overview with some comments on Michael Tomasello's The Cultural Origins of Human Cognition in the context of a seminar on the evolution of cognition. First, however, a warning: I am not really an expert on any of this material. I am just writing about what struck me having read the book.

Tomasello's book stands on several pillars:

1. Human cognition is significantly different from NHP cognition.
2. A modular approach to human cognition has several problems, not the least of which is the time-scale on which the modules must have evolved.
3. If humans had evolved an ability to see conspecifics as intentional and mental agents like themselves, then cultural learning/evolution could account for the distinctly human aspects of cognition.
4. Human historical and ontogenetic patterns provide evidence that the suggested ability is a better explanation than modular claims, due to the sequential and cumulative nature of human development.

While Tomasello musters some substantial evidence, especially for claim 1, there are several lacking areas. First, the part of the plausibility argument of 2/4 based on probability of distinct mutations happening seems somewhat strange. The probability of a mutation at any given point is so small, that whether one happened leading to Tomasello's suggested ability, or a small slew happened at once leading to the development of modules doesn't seem to be as big a deal to me as Tomasello would seem to claim.

The story for 3 is somewhat sketchy in terms of evidence, but Tomasello does make it sound plausible besides that. The story goes something like this:

1. Children develop the ability to see other humans as like themselves.
2. Joint attentional scenes allow children to begin seeing other humans as intentional agents.
3. This then allows for the development of basic language. Seeing others as intentional agents allows a child to determine the intent of words used in things such as naming games. Additionally, it allows for general imitation learning as opposed to the emulation learning of NHPs.
4. Children abstract due to social and individual pressures from simple language to verb island constructions, and later to more abstract grammar.
5. Greater social interaction and the development of seeing other humans as mental agents, having beliefs and desires like the self allows children to think discursively, develop simultaneous representability, self-regulation, and meta-cognition.

This is all quite interesting, but from the perspective of the course, it is somewhat disappointing. Tomasello focuses most of his efforts on point 3, whereas the seminar is most interested on what the nature of cognition is and how it might have evolved. Hopefully what we will be reading for the rest of the quarter will have a greater relevance to that topic.