![]() ![]() He suggested its nickname, “Alesi,” because “ales” means “ancestor” in the local Turkana language. Kenyan fossil hunter John Ekusi discovered the skull in 2014 in the Napudet area, west of Lake Turkana in northern Kenya. “So, as you can imagine, there are numerous possibilities for how that distribution came to be, and different researchers have suggested different hypotheses for where the common ancestor of the living apes and humans might be found.” Great timing “The living apes are found all across Africa and Asia - chimps and gorillas in Africa, orangutans and gibbons in Asia - and there are many fossil apes found on both continents, and Europe as well,” study co-author Christopher Gilbert, a paleoanthropologist at Hunter College in New York, told Live Science. As such, researchers were not sure what the last common ancestors of living apes and humans might have looked like, and even whether they originated in Africa or Eurasia. Fossil evidence from this part of the primate family tree is scarce, and consists mostly of isolated teeth and broken jaw fragments. Much remains unknown about the common ancestors of living apes and humans from the critical time when these branches diverged. (The last common ancestor that humans had with chimpanzees lived about 6 million to 7 million years ago.) These so-called hominoids - that is, the gibbons, great apes and humans - emerged and diversified during the Miocene epoch, approximately 23 million to 5 million years ago. It likely belonged to a fruit-eating, slow-climbing primate that resembled a baby gibbon, the researchers said.Īmong the living primates, humans are most closely related to the apes, which include the lesser apes (gibbons) and the great apes ( chimpanzees, gorillas and orangutans). The 13-million-year-old infant skull, which its discoverers nicknamed “Alesi,” was unearthed in Kenya in 2014. These baby steps would have been critical for the long childhood that is now often regarded as a keystone of human uniqueness.The most complete extinct-ape skull ever found reveals what the last common ancestor of all living apes and humans might have looked like, according to a new study. Extended brain growth in Lucy’s species may have provided a basis for the subsequent evolution of the brain and social behaviour in our ancestors. Lengthening the period of brain growth also stretches out a species’ highly impressionable learning period. And this can be linked to a long reliance on caregivers. ![]() Slowing brain development is a way to spread the energetic needs of highly dependent offspring over many years. Thus, this species may bridge the gap between the long childhoods humans enjoy today, and the shorter ones of our ape-like ancestors.Īmong primates in general, different rates of growth and maturation are associated with varied strategies of caring for infants. Our estimates suggest that by 2.4 years old, australopithecine children had brains that were only about 70% as big as adults, while average chimpanzees of the same age would have completed more than 85% of their brain growth. Virtual models of australopithecine brain cases reveal members of Lucy’s species had a chimpanzee-like brain organisation, but grew for a longer period of time. Surprisingly, however, its rate of brain development seemed to have shifted from the fast lane to the slow lane. This means the infant grew its molar teeth rapidly – similar to chimpanzees, and faster than humans. Our team’s dental experts calculated an age of 861 days, about 2.4 years. Having access to precise records of the Dikika child’s teeth, we were able to determine how old the child was when it died. The lengthy childhood of endangered orangutans is written in their teeth Similar to the growth rings of a tree, cross sections of teeth also reveal daily growth lines reflecting the body’s internal rhythms during childhood. ![]() The truth is in the toothĪ seldom recognised fact about humans and other primates is that our milk (baby) teeth and first molars are marked with a line formed at birth. Synchrotron imaging can also provide powerful insights into dental development. By forcing electrons to travel in a circular direction with magnetic fields, extremely bright light is produced that can be filtered and adjusted for research purposes.Ī benefit of this approach is that permanent impressions of brain folds on the bone can provide clues about key aspects of the brain’s organisation. This 3D animation shows the skull of the Dikika child.Ī synchrotron is a machine that accelerates electrons close to the speed of light and directs them around a large ring. ![]()
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