Neanderthal brain size at birth provides insights into the evolution of human life history
Ponce de León et al in today's P.N.A.S. discuss how the "Neanderthal brain size at birth provides insights into the evolution of human life history":
From birth to adulthood, the human brain expands by a factor of 3.3, compared with 2.5 in chimpanzees [DeSilva J and Lesnik J (2006) Chimpanzee neonatal brain size: Implications for brain growth in Homo erectus. J Hum Evol 51: 207–212]. How the required extra amount of human brain growth is achieved and what its implications are for human life history and cognitive development are still a matter of debate.
Likewise, because comparative fossil evidence is scarce, when and how the modern human pattern of brain growth arose during evolution is largely unknown. Virtual reconstructions of a Neanderthal neonate from Mezmaiskaya Cave (Russia) and of two Neanderthal infant skeletons from Dederiyeh Cave (Syria) now provide new comparative insights: Neanderthal brain size at birth was similar to that in recent Homo sapiens and most likely subject to similar obstetric constraints. Neanderthal brain growth rates during early infancy were higher, however.
This pattern of growth resulted in larger adult brain sizes but not in earlier completion of brain growth. Because large brains growing at high rates require large, late-maturing, mothers [Leigh SR and Blomquist GE (2007) in Campbell CJ et al. Primates in perspective; pp 396–407], it is likely that Neanderthal life history was similarly slow, or even slower-paced, than in recent H. sapiens.
Neanderthal mitochondrial genome sequenced
Green et al in today's edition of Cell publish a complete mitochondrial genome from a Neandertal:
A complete mitochondrial (mt) genome sequence was reconstructed from a 38,000 year-old Neandertal individual with 8341 mtDNA sequences identified among 4.8 Gb of DNA generated from ∼0.3 g of bone. Analysis of the assembled sequence unequivocally establishes that the Neandertal mtDNA falls outside the variation of extant human mtDNAs, and allows an estimate of the divergence date between the two mtDNA lineages of 660,000 ± 140,000 years. Of the 13 proteins encoded in the mtDNA, subunit 2 of cytochrome c oxidase of the mitochondrial electron transport chain has experienced the largest number of amino acid substitutions in human ancestors since the separation from Neandertals. There is evidence that purifying selection in the Neandertal mtDNA was reduced compared with other primate lineages, suggesting that the effective population size of Neandertals was small.
It’s a good thing they died out then, eh?
Ahh stupid and parochial science reporting:
Neanderthals have spoken out for the first time in 30,000 years, with the help of scientists who have simulated their voices using fossil evidence and a computer synthesiser.
For something less stink, see Kambiz's piece at Anthropology.net
Neanderthals wore makeup?
"Francesco d'Errico, an archaeologist from the University of Bordeaux, France, has found crafted lumps of pigment – essentially crayons – left behind by Neanderthals across Europe.
He says that Neanderthals, who most likely had pale skin, used these dark pigments to mark their own as well as animal skins. And, since body art is a form of communication, this implies that the Neanderthals could speak, d'Errico says."
Links: Hawks on Hominids, Personal DNA is a scam, genetics and voodoo linguistics
A few good links have come my way in the last few days, so here they are:
- John Hawks has more information on new Middle Pleistocene hominid from Turkey, that I mentioned a few days ago, and also has a fun piece describing his recent paper about genetic introgression in humans.
- The folks over at Anthropology.net tear apart an article by Meredith Small calling personal DNA testing a scam 'cos "if you want to know who you are, look in a mirror"
- Greater Blogazonia reviews the paper on genetic variation in Native American populations that we encountered two weeks ago in "Genetics meets voodoo linguistics".
Feminism wiped out Neanderthals?
This just in - feminism wiped out Neanderthals!
Among Neanderthals, hunting big beasts was women's work as well as men's, so it's a safe bet that female hunters got stomped, gored, and worse with appalling frequency. And a high casualty rate among fertile women - the vital "reproductive core" of a tiny population - could well have meant demographic disaster for a species already struggling to survive among monster bears, yellow-fanged hyenas, and cunning Homo sapien newcomers
Apparently, this is a result of a recent study, but wait, no, it's been kicking around for over a year. What is it about the work of pseudo-scientists that refuses to die?
Now if only stupid reporting wiped out bad science journalism...