4SH 3.2: Neanderthal News

Surely one of the most intensely scrutinized news topics of 2006 has been the Neanderthal, our nearest neighbor on the planet who may or may not have been closely related. Here's what folks are saying about a couple of the stories making the rounds about our Neanderthal (or as John Hawks and all the cool kids say 'Neandertal') neighbor.

Neanderthal Introgression

Two stories were released in the Proceedings of the National Academy of Science in early November that argued that there was evidence that the division between Early Modern Human and Neanderthal is not as clear as generations of scientists have thought, and that some mixing of genes (i.e., sex) may have occurred, meaning that modern humans are the result of an amalgam of early modern humans and Neanderthals, er, Neandertals (if I must be cool).

One of the reasons this is so very interesting, is because one important debate in paleoanthropology has been about evolutionary processes: did modern humans evolve from Homo erectus once in Africa and then migrate out in waves (called the Out of Africa hypothesis), or did humans evolve from Homo erectus several times around the world (called the multi-regional hypothesis)?

First up, the evidence for what scientists are calling 'introgression' between Neandertal and modern humans:

Here are the two papers:

• Andrei Soficaru, Adrian Dobos, and Erik Trinkaus. 2006. Early modern humans from the Pestera Muierii, Baia de Fier, Romania. Proceedings of the National Academy of Science 103:17196-17201
• Patrick D. Evans, Nitzan Mekel-Bobrov, Eric J. Vallender, Richard R. Hudson, and Bruce T. Lahn. 2006. Evidence that the adaptive allele of the brain size gene microcephalin introgressed into Homo sapiens from an archaic Homo lineage. Proceedings of the National Academy of Science Early Edition, Proceedings of the National Academy of Science 10.1073/pnas.0606966103 (open access).

Basically, Trinkaus and colleagues (in much published scholarly research, the lead scholar is listed last in the credits, so I'm referring to the results published in Soficaru et al.), investigated the hominin remains from a cave in Romania called Pester Muierii. They believe, on the basis of the morphology (the shape of the bones, in this case with special emphasis on the skulls), that the people living in the cave some 30,000 years ago were a blend of early modern human and Neanderthal. Lahn and colleagues (that is, Evans et al.) look at DNA evidence and conclude that, contrary to what we've believed in the past, there are significant differences within modern human populations, and that a 'brand' of genes called "Haplotype D" separated from the rest of humans some 1.1 million years ago and then merged back ('introgressed') into the population about 37,000 years ago. Since the entire genome of Neanderthals has not as yet been completed, this is an educated guess on the part of Lahn et al.

The best way to understand this is to read some of the blogs put together by my esteemed colleagues:

• An introduction to and anatomical evidence supporting Neandertal introgression (Part 1) , Kambiz Kamrani on Anthropology.net.
• The genetic evidence supporting Neandertal introgression (Part 2). Kambiz Kamrani on Anthropology.net.
• Neandertal Introgression, genetic style, by John Hawks
• Neandertal introgression, anatomically, by John Hawks
• Your Great * 1800 Grandmother was a Neanderthal, RPM on evolgen
• Gods must be Neanderthal males, Mangaluru Manjunatha on Incoherent Theories
• Round up on Introgression, Chet Snicker on Gene Expressions

More on Neanderthal Genome Sequencing

The second story I covered in detail just last week in Neanderthal DNA Studied, so I'll just post a few of the more recent blogs:

• Neandertal genome FAQ, from John Hawks
• Neanderthals among us?, Dan Collins on Protein Wisdom
• Understanding our neandertal cousins, Sclerotic Rings
• An Awesome Paleo-Microbiology Project, RPM on evolgen
• Neanderthal DNA Studied, which is my take on the genome sequencing thing
• What They Say about Neanderthals, which is a roundup of news and blog commentary from last week

Miscellaneous Tidbits and Background

• Know your primate, a great description of Neandertal by afarensis.
• The multiregional vs out of Africa debate by gringoperdido on Anthropology.net
• Neandertal or Neanderthal? John Hawks.
• NESPOS: 3D GIS Tools for Neaderthal Paleoarchaeology, Matt on GIS for Archaeology and CRM

Neanderthal, Neandertal. Let's call the whole thing off.

And, as a final word: Isn't the internet a wonderful place to learn about science?