Australopithecus afarensis | Smithsonian Human Origins Program Australopithecus afarensis Nickname: Lucy's species Where Lived: Eastern Africa (Ethiopia, Kenya, Tanzania) When Lived: Between about 3.85 and 2.95 million years ago Australopithecus afarensis is one of the longest-lived and best-known early human species—paleoanthropologists have uncovered remains from more than 300 individuals! Similar to chimpanzees, Au. afarensis children grew rapidly after birth and reached adulthood earlier than modern humans. Au. afarensis had both ape and human characteristics: members of this species had apelike face proportions (a flat nose, a strongly projecting lower jaw) and braincase (with a small brain, usually less than 500 cubic centimeters -- about 1/3 the size of a modern human brain), and long, strong arms with curved fingers adapted for climbing trees. Year of Discovery: 1974 History of Discovery: The species was formally named in 1978 following a wave of fossil discoveries at Hadar, Ethiopia, and Laetoli, Tanzania. First paper: Schmid, P., 2004.
Sciences et Avenir - Actualité des sciences et de la recherche - journal d'information Public Library of Science: Support PLoS "Lucy" Kin Pushes Back Evolution of Upright Walking? Lucy—a 3.2-million-year-old skeleton discovered in 1974—belongs to , a species which scientists think was an early direct ancestor of modern humans. An exceptionally petite female—her estimated height was 3.5 feet (1.1 meters)—Lucy's small frame has been interpreted as not being totally adapted for human-like, upright walking. (See: "6-Million-Year-Old Human Ancestor 1st to Walk Upright?" But the discovery of the 3.6-million-year-old male disproves that idea, said study co-author Yohannes Haile-Selassie , curator of physical anthropology at the Cleveland Museum of Natural History. "As a result of this discovery, we can now confidently say that 'Lucy' and her relatives were almost as proficient as we are walking on two legs, and that the elongation of our legs came earlier in our evolution than previously thought," Haile-Selassie said in a statement. {*style:<b>"Big Man" <i> A. </b>*} {*style:<b>Newfound Skeleton a Better Walker
Introduction Stephen Hawking: "Humans Have Entered a New Stage of Evolution" Although It has taken homo sapiens several million years to evolve from the apes, the useful information in our DNA, has probably changed by only a few million bits. So the rate of biological evolution in humans, Stephen Hawking points out in his Life in the Universe lecture, is about a bit a year. "By contrast," Hawking says, "there are about 50,000 new books published in the English language each year, containing of the order of a hundred billion bits of information. This means Hawking says that we have entered a new phase of evolution. But what distinguishes us from our cave man ancestors is the knowledge that we have accumulated over the last ten thousand years, and particularly, Hawking points out, over the last three hundred. "I think it is legitimate to take a broader view, and include externally transmitted information, as well as DNA, in the evolution of the human race," Hawking said. Casey Kazan Related Galaxy posts: Immense Journey Source:
Evolution in Action: Lizard Moving From Eggs to Live Birth Evolution has been caught in the act, according to scientists who are decoding how a species of Australian lizard is abandoning egg-laying in favor of live birth. Along the warm coastal lowlands of New South Wales (map), the yellow-bellied three-toed skink lays eggs to reproduce. But individuals of the same species living in the state's higher, colder mountains are almost all giving birth to live young. Only two other modern reptiles—another skink species and a European lizard—use both types of reproduction. Evolutionary records shows that nearly a hundred reptile lineages have independently made the transition from egg-laying to live birth in the past, and today about 20 percent of all living snakes and lizards give birth to live young only. But modern reptiles that have live young provide only a single snapshot on a long evolutionary time line, said study co-author James Stewart, a biologist at East Tennessee State University. Eggs-to-Baby Switch Creates Nutrient Problem
How did life originate? How did life originate? Living things (even ancient organisms like bacteria) are enormously complex. However, all this complexity did not leap fully-formed from the primordial soup. Instead life almost certainly originated in a series of small steps, each building upon the complexity that evolved previously: Simple organic molecules were formed. Multicellularity evolved.
How We Are Evolving Thousands of years ago humans moved for the first time into the Tibetan plateau, a vast expanse of steppelands that towers some 14,000 feet above sea level. Although these trailblazers would have had the benefit of entering a new ecosystem free of competition with other people, the low oxygen levels at that altitude would have placed severe stresses on the body, resulting in chronic altitude sickness and high infant mortality. Earlier this year a flurry of genetic studies identified a gene variant that is common in Tibetans but rare in other populations. This variant, which adjusts red blood cell production in Tibetans, helps to explain how Tibetans adapted to those harsh conditions. The Tibet findings seemed to bolster the notion that our species has undergone considerable biological adaptation of this sort since it first left Africa perhaps 60,000 years ago (estimates range from 50,000 to 100,000 years ago). Select an option below: Customer Sign In