Category Archives: Darwin

Overbite: The European-Asian tooth connection

Sorry for the sensationalist title to the blog, but I couldn’t resist, honestly. Apparently, a study by  Spain’s National Centre for Research on Human Evolution http://www.cenieh.es/en_index.php has proposed that modern Europeans are descended more from Asians than Africans. The study, as covered by AFP newswire, http://news.yahoo.com/s/afp/20070807/sc_afp/usscienceorigins was probably conducted by the Centre’s Group of Dental Anthropology http://www.cenieh.es/en_investigacion/g1inicio.php. The group studied the characteristics of the teeth of more than 5,000 teeth from humans from Africa, Asia and Europe dating back millions of years, and saw greater similarities between European and Asian teeth than between European and African teeth.
So does this negate the Out of Africa theory? Unlikely, in my opinion. The Out of Africa theory is so well supported by the common mitochondrial DNA (about 150,000 years ago) and Y chromosome marker (about 60,000 years ago) that all humans carry, that it will take more than the shape of teeth to overturn it. What the study does, in my opinion, is underline the complexity of human evolution; there may have been more movements between European and Asian populations than earlier believed. 
So what’s the debate all about?  About 100,000 years ago, Earth had several species of hominids: Homo sapiens in Africa and the Middle East; Homo erectus in Southeast Asia and China; and Neanderthals in Europe. But by about 25,000 years ago, only Homo sapiens remained. What happened to the earlier hominids? Were they replaced by modern humans, or did they interbreed with them? The Out of Africa theory supports the former hypothesis, and the Multiregional Evolution theory the latter. The main proponent of the Out of Africa Theory is British paleoanthropologist Chris Stringer. The theory got a major boost in the 1990s from mitochondrial DNA studies by Allan Wilson and Rebecca Cann which suggested that all humans ultimately descended from one female: the Mitochondrial Eve. The main proponent of the Multiregional Evolution theory is University of Michigan professor Milford H. Wolpoff. http://www.mnh.si.edu/anthro/humanorigins/faq/Encarta/diversity.htm#ooa 
The debate has been going on for a very long time now, and it’s likely to go on for some more time. I personally feel the Out of Africa theory is stronger, but I’m no scientist. 

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Darwin on the Web

All of Darwin’s writings, from his seminal Origin of Species and Descent of Man to the jottings in the notebook he carried around with him on The Beagle, have been published on the World Wide Web. http://darwin-online.org.uk/
It’s an extremely functional site, where you can select your favourite mode of reading, with or without images. Slight minuses are that the site has a slightly dated look, and it doesn’t offer easier-to-read .pdf or .lit versions of the books for download. But these are minor in comparison with the wealth of information available on the site, and the 15 million hits the website has received since it came into being prove it.