Early human ancestors’ ‘brain food’ - crocs, fish and hippos!

WASHINGTON - Our early ancestors, living in what is now northern Kenya, feasted on fish and other aquatic animals such as turtles and crocodiles - foods which probably played a major role in the development of a larger, more human-like brain, new research reveals.

The study, which offers first-ever evidence of dietary variety among early pre-humans, appears in Proceedings of the National Academy of Sciences.

A team of researchers that included Johns Hopkins University geologist has found that early hominids living in what is now northern Kenya ate a wider variety of foods than previously thought, including fish and aquatic animals such as turtles and crocodiles. Rich in protein and nutrients, these foods may have played a key role in the development of a larger, more human-like brain in our early forebears, which some anthropologists believe happened around 2 million years ago, according to the researchers’ study.

Naomi Levin, an assistant professor in the Morton K. Blaustein Department of Earth and Planetary Sciences at Johns Hopkins’ Krieger School of Arts and Sciences, said: “Considering that growing a bigger brain requires many nutrients and calories, anthropologists have posited that adding meat to their diet was key to the development of a larger brain.

“Before now, we have never had such a wealth of data that actually demonstrates the wide variety of animal resources that early humans accessed.”

Levin served as the main geologist on the team, which included scientists from the United States, South Africa, Kenya, Australia and the United Kingdom.

In 2004, the team discovered a 1.95 million-year-old site in northern Kenya and spent four years excavating it, yielding thousands of fossilized tools and bones.

According to paper’s lead author David Braun of the University of Cape Town (South Africa), the site provided the right conditions to preserve those valuable artefacts.

Braun said: “At sites of this age, we often consider ourselves lucky if we find any bone associated with stone tools. But here, we found everything from small bird bones to hippopotamus leg bones.”The preservation of the artefacts was so remarkable, in fact, that it allowed the team to meticulously and accurately reconstruct the environment, identifying numerous fossilized plant remains and extinct species that seem to be a sign that these early humans lived in a wet - and possibly even a marshy - environment.

Levin said: “Results from stable isotopic analysis of the fossil teeth helped refine our picture of the paleoenvironment of the site, telling us that the majority of mammals at the site subsisted on grassy, well-watered resources.

“Today, the Turkana region in northern Kenya is an extremely dry and harsh environment. So, clearly, the environment of this butchery site was very different 1.95 million years ago - this spot was much wetter and lush.”

Using a variety of techniques, the team was able to conclude that the hominids butchered at least 10 individual animals - including turtles, fish, crocodiles and antelopes - on the site for use as meals.

Cut marks found on the bones indicate that the hominids use simple, sharp-edged stone tools to butcher their prey.

Levin said: “It’s not clear to us how early humans acquired or processed the butchered meat, but it’s likely that it was eaten raw.”

The team theorizes that the wet and marshy environment gave early pre-humans a way to increase the protein in their diets (and grow larger brains) while possibly avoiding contact with larger carnivores, such as hyenas and lions. (ANI)