Based on their evidence, the team suggest that Lucy died falling out of a tree. The researchers believe the injuries observed were severe enough that internal organs could also have been damaged. They also indicated that many of the breaks occurred perimortem, around the time of death, rather than over time as the bones became fossilised. Researchers studied injuries to Lucy's bones to see whether they offered insights into how she died, publishing their findings in 2016.ĬT scans revealed fractures in her shoulder joint and arms similar to those observed in people who fall from a great height, as if she reached out to break her fall. afarensis was the oldest hominin species known, although far older species have since been found. Only after analysing other fossils subsequently uncovered nearby and at Laetoli in Kenya did scientists establish a new species, Australopithecus afarensis, four years after Lucy's discovery.Īt the time, Au. Philosophical Transactions of the Royal Society B, 2013 DOI:10.1098/ thought Lucy was either a small member of the genus Homo or a small australopithecine. "Hand Before Foot? cortical somatotopy suggests manual dexterity is primitive and evolved independently of bipedalism" Iriki, “but our new method of using comparative brain physiology to decipher ancestral traces of adaptation may allow us to re-examine Darwin’s theories”. “Evolution is not usually thought of as being accessible to study in the laboratory”, stated Dr. The findings suggest that the parallel evolution of two-legged locomotion and manual dexterity in hands and fingers in the human lineage were a consequence of adaptive pressures on ancestral quadrupeds for balance control by foot digits while retaining the critical capability for fine finger specialization. The brain study was supported by analysis of the well-preserved hand and feet bones of a 4.4 million year-old skeleton of the transitional bipedal hominin Ardipithecus ramidus, a species that retained hand dexterity that preceded the human-monkey lineage split. “In early quadruped hominids, finger control and tool use were feasible, while an independent adaptation involving the use of the big toe for functions like balance and walking occurred with bipedality,” the authors explained. Manual dexterity was not further expanded in monkeys, but humans gained fine finger control and a big toe to aid bipedal locomotion. These findings suggest that early hominids evolved dexterous fingers when they were still quadrupeds. However, the researchers found new evidence that monkey toes are combined into a single map, while human toes are also fused into a single map, but with the prominent exception of the big toe, which has its own map not seen in monkeys. With these maps, the researchers confirmed previous studies showing that single digits in the hand and foot have discrete neural locations in both humans and monkeys. In a study published today in Philosophical Transactions of the Royal Society B, the researchers employed functional magnetic resonance imaging in humans and electrical recording from monkeys to locate the brain areas responsible for touch awareness in individual fingers and toes, called somatotopic maps. Gen Suwa, an anthropologist from the University of Tokyo Museum, have overturned the common assumption that manual dexterity evolved after the development of bipedal locomotion freed hominid hands to use fingers for tool manipulation. Combining monkey and human behavior, brain imaging, and fossil evidence, a research team led by neurobiologist Dr.
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