'Nutcracker Man' Ate Tiger Nuts

Author: Charles Q. Choi

Date of Publication: January 8, 2014

Link: http://www.livescience.com/42433-nutcracker-man-ate-tiger-nuts.html

Summary:

The "Nutcracker Man" is an extinct relative of humans, earning its nickname from its huge jaw and giant molars.  Officially named the paranthropus boisei, they lived around 1.4 million to 2.4 million years ago alongside humans across East Africa.  It was assumed that the P. boisei ate seeds, nuts, and other tough foods but their teeth did not support that.  After a study of the teeth of the P. boisei had been completed, the results suggested that the P. boisei actually fed on softer foods, and that they largely depended on C4 plants, such as grasses and sedges to sustain life.  A huge question was whether or not such foods could be nutritious enough for a hominin with a large brain and medium sized body.  To solve this question, paleoanthropologist Gabriele Macho studied one year old baboons within similar environments of the P. boisei.  A huge reason on why one year old baboons were chose is because of the fact they required more nutrition than adults and therefore might have had a closer diet requirements of a large brained hominin than an adult baboon.  It turns out that one year old baboons eat large numbers of C4 plants known as tiger nuts, which are grass bulbs that contain sufficiently high amounts of vitamins, minerals, and fatty acids all important to the hominin brain.  Based on the amount of time it took for baboons to gather the tiger nuts, it was estimated that because of their superior manual dexterity, the P. boisei could gather the tiger nuts just as fast as adult baboons and at least twice as fast as young baboons.  Tiger nuts are rich in abrasive starches and so the P. boisei would have to chew on them for a long time in order to fully digest them.  This may be why the anatomy of the organism is unusual because the features of its jaws and teeth are results of not eating hard foods but repetitive chewing.  While 80% of their diet was from the tiger nuts, the P. boisei most likely supplemented the rest of their diets with fruits and invertebrates.

Relevance:

This article relates to the evolution unit and more specifically how natural selection helps organisms adapt to their environments and allows them to survive by choosing certain characteristics and traits.  In this situation, it was a mystery on how the P. boisei were able to survive a million years since the C4 plants they ate most likely did not have enough nutrients to nourish a hominin with a large brain and medium sized body.  After it was known that the tiger nuts held enough nutrients that could sustain such an organism, the only problem would be finding a way to digest it since it contained abrasive starches.  Natural selection must have selected the large jaw trait so that the P. boisei would be able to slowly grind the tiger nuts down into digestible pieces so they could receive the necessary calories they needed to survive.  With, natural selection's help, these organisms were able to survive a million years because of the fact that they were able to evolve their teeth to survive and adapt in their environment.