Friday, June 4, 2010

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 and nutrition 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.


Marcel F. Williams said...

In other words, early Homo pretty much ate everything it could get its hands on just as Homo sapiens does today!

Does a healthy diet help the brain. Probably yes. However, the morphology of the neocortex clearly indicates that those areas in the human brain that increased the most were related to vocalization and manual dexterity.

Hmmm! I wonder what humans use their hands and their voices for???

Raymond Ho, FCD said...

Maybe to make more efficient tools to cut those seafood with and a coordinated effort to gather fishes! :)

These findings predates Homo erectus so I'd speculate that the seafood probably provided enough energy and nutrition to just make the expansion happen without much concentration on the specific regions.