Around 3.6 million years ago, a pair of Australopithecus afarensis — a species of ancient ancestor made famous by the fossil Lucy — were walking through wet mud in Laetoli, Tanzania. This was likely just an ordinary day, but then something extraordinary happened: A nearby volcano erupted, covering their freshly made footprints in ash, preserving their shape, and locking this moment in time. Show
We know very little about the Australopithecus, a long-extinct hominid species that may be our ancestral link to the apes. Basic facts, like whether they could climb trees, are subjects of scientific debate. The footprints, recently discovered by archaeologists, not only give us a glimpse into how these creatures walked but also, amazingly, give us some clues about how they behaved. “When we reached the footprint layer and started to clean it with a soft brush and saw the footprints for the first time, it was really one of the most exciting times of my life,” Marco Cherin, a paleontologist at the University of Perugia in Italy, recently told the Guardian. Yes, footprints are really that exciting. Here’s why.Publishing in the journal e-life, Cherin and his colleagues in Italy say the footprints at the Laetoli site represent a significant breakthrough for a few reasons. One is that the Laetoli site is already home to footprints of three Australopithecus individuals that were discovered in 1976, which are the oldest-known footprints of an upright-walking human ancestor. These two new sets of footprints are thought to have been formed at the same time. And therefore, it’s possible these two new individuals were walking with the other three, separated by about 150 meters. While skeletal remains give anthropologists clues to an ancestor’s biology, they hold few clues to that ancestor’s actions. Skeletons, Cherin tells me in an email, “often give only indications on the skeletal anatomy.” Footprints, however simple they may appear, provide rich data. They “give us information not only on the ‘shape’ of their makers, but also on their behavior,” Cherin says. More so than a skeleton, footprints represent a snapshot in time. “They are a real ‘photograph’ on a precise moment of the deep past,” he says. “Like a spotlight on a prehistoric scene, fossil tracks provide data about the locomotion, biomechanics, and body size of the extinct creatures and reveal the diversity among individuals, explaining even their reproductive strategies,” Giorgio Manzi, another author on the study, tells me in an email. And already this snapshot is firing up the imaginations of researchers, who have put forth a flurry of new hypotheses about the Australopithecus. Such as:
As a story in National Geographic makes clear: All of these hypotheses are in dispute. It’s really difficult to say if the footprints belong to females or juveniles (we don’t have many examples of Australopithecus feet to know for sure how their size correspond to height). From there, it may be a stretch to assume that if a male was with more than two females, they were all his mates. And finally, there isn’t conclusive evidence that these individuals were, indeed, all with one another. But this is what the footprints do: activate imagination. Anthropologists are in the business of finding out and writing the long-forgotten history of life on Earth. Just a footprint alone is enough to tantalize them. “Footprints in general take on an even greater value in the case of hominins [human ancestors],” Cherin says. They “are creatures of which we know very little, even though they are so closely related to us.” Watch: How scientists discovered a new human ancestor
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Is the study of anatomical and behavior human evolution as evidenced by the fossil record?Paleoanthropology studies the evolution of primates and hominids from the fossil record and from what can be determined through comparative anatomy and studies of social structure and behavior from our closest living relatives.
Is the branch of osteology that studies the evidence of disease and injury in human skeletal remains from archaeological sites?Paleopathology, also spelled palaeopathology, is the study of ancient diseases and injuries in organisms through the examination of fossils, mummified tissue, skeletal remains, and analysis of coprolites.
Is the subdiscipline of osteology?Osteology is the scientific study of bones, and is a subdiscipline of anthropology and archeology.
What unique strategy allows humans to adapt to the natural environment?What strategy is unique to humans develop that allows them to adapt to the natural environment? changes in the genetic make-up of a population from one generation to the next.
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