Latest news with #KayeReed
Yahoo
2 days ago
- Science
- Yahoo
You've met 'Lucy.' Now ASU scientists unearth another clue to the origin of humans
Though she works thousands of miles from home, Arizona State University research scientist Kaye Reed is used to 110-degree heat. For days at a time, Reed and her colleagues walk through Ethiopia's baking Awash Valley, scanning the ground with their eyes. It's uncomfortable, Reed said, but it's all worth it when they make the kind of discovery revealed in a paper released on Aug. 13. Reed and a team of international scientists believe they have added a new member to humanity's family tree — a yet undocumented species of hominid, or upright ape, that walked the east African grasslands more than 2.6 million years ago. She and the team made the discovery when they found three collections of ancient primate teeth lying on the ground during fossil searches at the Ledi-Geraru Research Project Area led by ASU. Scientists believe the new species could offer clues about the conditions that produced humanity's ancestors, though this species was likely not a direct predecessor to homo sapiens. The species lived in an area and time at which future humans may have first emerged, according to the fossil record. Scientists know very little about the new species so far, Reed said. A collection of teeth is useful for understanding the animal's diet, but arms, legs, and skulls provide a fuller picture of how it moved around its habitat. Those clues help researchers understand the conditions in which the species survived. 'Evolution doesn't work like that' Those insights could shine light on a critical, but poorly understood, chapter in human evolution. The new species may have been one of the last members of a dying family of human ancestors known as the australopithecus genus, which includes the famous 'Lucy,' whose fossil was unearthed in 1974. As its relatives were dying out, this new species would have watched the rise of humanity's genus, homo, which was the first to commonly use stone tools and eat meat. 'If it's a different species of Australopithecus… that means (Lucy) either went extinct or somehow evolved into this new species,' said Reed, part of the Institute of Human Origins at ASU. 'The fact that it also occurs at roughly the same time as the genus Homo suggests to us that there was a change in the climate and the habitats, which you had to change to survive.' With the new species, Reed believes at least four species of upright apes were living in east Africa at the same time, including two australopithecus, one homo, and a species from an offshoot called paranthropus. Scientists don't know much about the transition from Australopithecus to homo because the fossil record during that period is surprisingly slim, Reed said. But this new discovery makes at least one thing clear: As with much of evolution, this transition was not a straightforward line. The process of human evolution is full of dead ends and overlaps, with multiple species of upright apes evolving alongside each other, some successful and some not. 'Everybody always posts that thing where there's a hunched over ape, and then there's a kind of upright ape, and then something with a bigger brain, and it's just from one to one to one," Reed said. "Evolution doesn't work like that.' Even the distinctions between ancestors and descendants is sometimes unclear. Reed had to grapple with this complexity when she and her colleagues attempted to identify the teeth they had found. The team considered multiple alternatives, including the possibility that the teeth belonged to transitional forms of already known species. While some species distinctions are obvious, Reed said, some are almost a matter of opinion, pointing out that some scientists might have classified the new teeth as a variant of the 'Lucy' species. 'Another scientist that I know might put these teeth into (Lucy's species). He doesn't care about what he would consider the minor differences,' Reed said. A famous discovery: On a November day 50 years ago, a scientist found 'Lucy' and rewrote our origin story Still searching for more clues The appearance of the new species could also help scientists better understand why humanity's closest ancestors, the homo group, emerged when they did. Some scientists have argued that homo species evolved partially as a response to a drier habitat with more grasslands, but this new species shows that an Australopithecus species could also survive in that new, dry environment. 'You have longer dry seasons, so animals are stressed. Many that we see in Lucy's time are eating trees, but then they switch to grass, and in that time period we find the Australopithecus is different from what it was,' Reed said. More clues about the new species' diets will help Reed and other researchers understand how it interacted with other walking apes and whether this was a case where humanity's ancestors had to out-compete their relatives to grab hold of the future. 'If they ate the same thing, it's going to be tough for one of them to survive … and so maybe one of them out-competed the other,' Reed said. 'But maybe they weren't eating the same thing, and that's how they split when it got really dry.' Traces of carbon and nitrogen in ancient teeth can indicate what kinds of plants or meat the animal ate. To discover that an australopithecus was scavenging meat would make it a much more direct competitor with human ancestors, Reed said. Otherwise, scientists have many miles to walk before they can fully understand the new creature they might have brought to light. That will mean many more hours searching for the right sediments and pacing, meticulously, in the east African heat. 'To find this stuff is really exciting,' Reed said. 'We just have to find more information to put the puzzle together.' Austin Corona covers environmental issues for The Arizona Republic and azcentral. Send tips or questions to Environmental coverage on and in The Arizona Republic is supported by a grant from the Nina Mason Pulliam Charitable Trust. This article originally appeared on Arizona Republic: ASU scientists may have found a new species related to humans Solve the daily Crossword
The Independent
5 days ago
- Science
- The Independent
Fossil teeth lead to discovery of human species that lived alongside our oldest ancestors
Fossil teeth unearthed in Ethiopia suggest two distinct human ancestor species lived alongside each other between 2.6 and 2.8 million years ago, reshaping what is known about our evolution. The 13 teeth come from a Homo species that lived in Ethiopia's Afar region, overlapping with the hominin ancestor Australopithecus. The teeth, found at the Ledi-Geraru archaeological site, reveal that the oldest members of the Homo genus coexisted with the Australopithecus. 'These specimens suggest that Australopithecus and early Homo coexisted as two non-robust lineages in the Afar region before 2.5 million years ago,' researchers said, 'and that the hominin fossil record is more diverse than previously known.' According to Kaye Reed, a co-author of the study, the discovery shifts our perception of human evolution. "Here we have two hominin species that are together. And human evolution is not linear, it is a bushy tree, there are lifeforms that go extinct,' Dr Reed explained. 'This new research shows the image many of us have in our minds of an ape to a Neanderthal to a modern [human] is not correct. Evolution doesn't work like that.' Analysis of the teeth, published in the journal Nature, shows they belonged to a new Homo species rather than Australopithecus afarensis – represented by the famous ' Lucy' specimen – which last appeared 2.95 million years ago. 'The new finds of Homo teeth from 2.6 to 2.8 million-year-old sediments confirm the antiquity of our lineage,' Brian Villmoare, lead author of the study, said. The newly discovered ancestor species does not have a name yet. More fossils are needed for that to happen. Researchers dated the specimen based on the fossil site's volcanic and tectonic activity. The region is home to many volcanoes that spew ash containing crystals called feldspars. "We can date the eruptions that were happening on the landscape when they are deposited," Christopher Campisano, another author of the study, explained, referring to feldspars. "And we know that these fossils are interbed between those eruptions, so we can date units above and below the fossils. We're dating the volcanic ash of the eruptions that were happening while they were on the landscape.' Examining the fossils and the landscape together allowed researchers to recreate the environment millions of years ago. They found that the landscape traversed by these ancient human ancestors 2.6 to 2.8 million years ago was a stark contrast to modern times. Back then, rivers flowed through a vegetated landscape into shallow lakes that expanded and contracted over time. "The geology gives us the age and characteristics of the sedimentary deposits containing the fossils,' said another study author Ramon Arrowsmith. 'It is essential for age control.' It remains unclear if the Lucy species and the Australopithecus species ate the same things and competed with each other for food. In further studies, researchers hope to examine the tooth enamel of the species to find out what they ate.
