Archive for June 2010
Were The Americas Settled Twice?
A team of paleoanthropologists report in PLoS One analyzed the skulls of several dozen 11,000 year old Paleoamericans and compared them to the skulls of more than 300 1,000 year old Amerindians. They concluded that based on the morphology, there were two distinct waves of colonizers from Asia.
11,000 Year Old Lagoa Santa Brazil Paleoamerican Skull
While we know from a couple genetic studies there are at least two, if not 3 or more waves of colonizers, the morphological evidence is now beginning to make a lot more sense along with the genetic evidence. There’s some concern why the authors didn’t have more North American and Asian samples for comparison, but that’s almost always a critique in any anatomical study.
Two comments in the Science Now news article are particularly entertaining regarding this topic:
“Very interesting–don’t tell some of the tribes in california–they won’t be able to handle real information like this.”
“Exactly. It sounds like the Amerindians stole the land from the Paleoindians? I guess they should pay restitution, right?”
- Hubbe, M., Neves, W., & Harvati, K. (2010). Testing Evolutionary and Dispersion Scenarios for the Settlement of the New World PLoS ONE, 5 (6) DOI: 10.1371/journal.pone.0011105
Early hominin ate “seafood”, possible reason for the expansion of the brain
Recent archaeological find in Koobi Fora, Kenya suggests that our early ancestors might have dined on “seafood” to compensate for the energy needed for the expansion of the brain. The excavated site dates 1.95 million years ago, which predates Homo erectus, reveals distinct faunal remains (some with evidence of butchery) and Oldowan artifacts. Detailed in latest PNAS edition, archaeologist David Braun and his team found an assemblage of bones from terrestrial and aquatic animals such as fishes, turtles and even crocodiles along with stone fragments (Oldowan tools) that are thought to be used to cut these animals with.
Photograph and scanning electron microscope image of a reptile bone scored by cuts. Image from PNAS.
“These aquatic foods are really important sources of the long-chain polyunsaturated fatty acids and docosahexaenoic acid that are so critical to human brain growth,” said co-author and paleoanthropologist Dr. Richmond. “Finding these foods in the diets of our early ancestors suggests they may have helped to lift constraints on brain size and fuel the evolution of a larger brain.”
Braun posits that if these early hominins indeed ate these terrestrial and aquatic animals (fishes, turtles and crocodiles), then they would have ingested enough calories and fatty acids needed for the expansion of the brain without having to scavenge for animal remains. Braun thinks that these small-bodied hominins would have avoided the dangerous risk of confronting with larger scavengers.
Read more:
Crocs and fish key to human evolution on PhysOrg.
Did Dining on Seafood Help Early Humans Grow These Big Brains? on Discover.
Fossils Suggest Menu That Made Humans Possible on Wired.
Early hominin diet included diverse terrestrial and aquatic animals 1.95 Ma in East Turkana, Kenya (Braun et al., 2010) on PNAS.
Originally posted on The Prancing Papio.
