A new study has shed light on how apes evolved into two-legged species, as these creatures used to eat leaves from trees rather than fruits around 21 million years ago. According to the study, this evolution was largely the result of the transformation of a dense forest in Africa that slowly became dry, thus paving the way for the formation of open grasslands. '
Previously, researchers believed equatorial Africa during the Early Miocene was thickly covered in forest, and that woodlands and grasslands emerged 7 to 10 million years ago, but this study suggests it was more like 21 million years ago.
The study evoked a suggestion; the anatomy of modern apes evolved among leaf-eating apes in open woodlands.
Across nine fossil site complexes, the researchers conducted palaeontological and geological fieldwork, during the 10 long years of study. In order to reconstruct ancient habitats thousands of fossil plants and animal remains were collected.
The C4 plants found in tropical savannahs were also a part of the research. The study revealed that these grasses were already a part of the ecosystem about 21 million years ago. This indicates open grasslands and scrubs existed much earlier than previously thought.
According to a report published in The Times, a very early ape named Morotopithecus, was not an inhabitant of a dense jungle, but it lived in an open grassy landscape in woodland areas.
Morotopithecus scampered on the floor like a monkey where it had an upright stance and did not walk on two legs as humans do.
Stony Brook University, Associate Professor in Department of Anthropology, James Rossie explained that an assessment of Morotopithecus' molars exhibits an elongation with well-developed crests, ideal for shearing leaves. Molars designed to crush fruits are more rounded. Carbon isotope signatures of the enamel of these apes indicated they fed on water-stressed plants, meaning that they were subjected to seasonal periods of dryness.
"Morotopithecus is regarded as one of the best representatives of the ancestors to all of the living apes and humans," said Kieran McNulty, one of the co-authors of the study in Science.
The upright postures of the apes evolved in "closed-canopy forests," where the branches of the trees touch the branches of other trees, added McNulty.
Morotopithecus and other species of apes lived in much more open spaces where there were trees around but they would have to get down from one tree to get to another.
Experts believe that the findings of this study can be further used to create a new framework for studying how environmental changes in Africa played a pivotal role in determining the evolution of apes, and sometimes human beings.
