Science Post Purge

It's time to purge. I've collected a number of science blog posts that I have intended to point out or comment on but have not. So here they are; feel free to comment on them.


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First John Hawks lays out the basics between the Multiregional vs. Out of Africa hypotheses concerning human origins and expansion.

Both hypotheses have to account for the same basic set of facts:

-Humans first left Africa and established populations in other parts of the world (first southern Asia, China, and Java, later Europe) by 1.8 million years ago.

-Humans today are quite different anatomically and behaviorally from archaic people (that is, most humans before 40,000 years ago) anywhere in the world. Recent people are called "modern" humans.

-Human populations today are genetically very similar to each other.

-African populations today are more genetically diverse than populations in other parts of the world.

-Recent humans in Europe and Asia share a few features with the ancient archaic people who lived in those places before 40,000 years ago.

Carl Zimmer reports on a talk by Alan Templeton arguing (if I understand it correcty) that the truth may lie between these two poles. This post is worth checking out for the graphic illustrating human gene flow at the bottom.

While I'm referencing Carl Zimmer, I want to point out a few more of his posts. Here he discusses a recent paper on how the various members of the cat family relate to each other. Then there is a discussion of pandas, thumbs, and the funny paths of evolution. I've been holding onto this one since September, but it may be the most fascinating. In fact, I quote the opening paragraph to give you a taste.

A lot of people think of viruses and bacteria in our bodies as nothing more than pests. It's certainly true that a lot of them do an excellent job of making us ill. But some viruses and bacteria merged with our ancestors over the course of billions of years, and if you were to have them removed from your body today, you'd die faster than if you'd gotten a massive dose of Ebola.

At The Panda's Thumb there is a discussion of "junk DNA."

Pharyngula summarizes a paper about a transitional fossil and its meaning for limb evoution.

Finally, Michael Ruse discusses several approaches to the question, "were humans inevitable?"

(I apologize for using the word "discuss" a lot. Maybe next time I'll consult a thesaurus.)