Skeletal structure of humans and other primates. A comparison of the skeletal structures of gibbons, humans, chimpanzees, gorillas and orangutans. The therapsids had temporal fenestrae larger and more mammal-like than pelycosaurs, their teeth showed more serial differentiation, their gait was semi-erect and later forms had evolved a secondary palate. A secondary palate enables the animal to eat and breathe at the same time and is a sign of a more active, perhaps warm-blooded, way of life. [21] They had lost gastralia and, possibly, scales.

Evolutionman

Evolution of the amniotic egg gives rise to the amniotes, tetrapods that can reproduce on land and lay shelled eggs on dry land. They did not need to return to water for reproduction nor breathing. This adaptation and the desiccation-resistant scales gave them the capability to inhabit the uplands for the first time, albeit making them drink water through their mouths. At this stage, adrenal tissue may have concentrated into discrete glands. A digital rendering of a satellite view of the Arabian Peninsula, where humans are believed to have migrated from Africa roughly 55,000 years ago Human evolution is a puzzle with thousands of fossil pieces and billions of DNA fragments. As new fossils continue to be uncovered and added to the human family tree, new dating techniques and climate data are providing a more accurate picture of the conditions in which our ancient relatives evolved. It is thought that A. afarensis was ancestral to both the genus Australopithecus and the genus Homo. Compared to the modern and extinct great apes, A. afarensis had reduced canines and molars, although they were still relatively larger than in modern humans. A. afarensis also has a relatively small brain size (380–430cm³) and a prognathic (anterior-projecting) face. The ‘multi-regional’ model proposes that the evolution of Homo sapiens took place in several places over a long time. The mixing of the various populations eventually led to the single Homo sapiens species we see today. Earliest AncestorSome freshwater lobe-finned fish (sarcopterygii) develop limbs and give rise to the Tetrapodomorpha. These fish evolved in shallow and swampy freshwater habitats, where they evolved large eyes and spiracles. Dawkins, R. (2005), The Ancestor's Tale: A Pilgrimage to the Dawn of Evolution, Houghton Mifflin Harcourt, ISBN 978-0-618-61916-0

Evolution | The Smithsonian Institution Introduction to Human Evolution | The Smithsonian Institution

As with fossils, tool advancements appear in different places and times, suggesting that distinct groups of people evolved, and possibly later shared, these tool technologies. Those groups may include other humans who are not part of our own lineage.Just by looking at DNA from present day individuals we’ve been able to infer a pretty good outline of human history,” Akey says. “A group dispersed out of Africa maybe 50 to 60 thousand years ago, and then that group traveled around the world and eventually made it to all habitable places of the world.” From the time of Homo erectus, Homo species migrated out of Africa. Homo sapiens extended this migration over the whole planet. In the fifteenth and sixteenth centuries, Europeans explored the world. On the various continents, explorers met unknown populations. The Europeans were wondering if those beings were humans or not. But actually, those populations were also descendants of the men and women who colonized the earth at the dawn of mankind. In much earlier times, there was a theory that there were several races of humans, based mostly on skin color, but this theory was not supported by science. Current studies of DNA show that more than seven billion people who live on earth today are not of different races. There is only one human species on earth today, named Homo sapiens. Suggested Reading A separate species, Homo neanderthalensis, had a common ancestor with humans about 660,000 years ago, and engaged in interbreeding with Homo sapiens about 45,000 to 80,000 years ago. Although their brains were larger, Neanderthals had fewer social and technological innovations than humans, and they eventually died out. Theories of Early Human Evolution The theory that the savannah was expanding due to increasingly arid conditions, which then drove hominin adaptation. turnover pulse hypothesis Visitors to the gallery will also be able to see a replica of one of the most famous bipedal hominins, the Australopithecus afarensis known as Lucy, who lived around 3.2 million years ago.

Human evolution | Natural History Museum Human evolution | Natural History Museum

Panderichthys is a 90–130cm (35–50in) long fish from the Late Devonian period (380 Mya). It has a large tetrapod-like head. Panderichthys exhibits features transitional between lobe-finned fishes and early tetrapods.Homo erectus was also an innovator. It produced far more sophisticated tools than had any of its predecessors, and was probably the first to control fire. Some researchers think that it invented cooking, improving the quality of its diet and leading to an energy surplus that allowed bigger brains to evolve. It is certainly true that the brain size of Homo erectus grew dramatically during the species’s 1.5-million-year existence. Some of the very earliest individuals had a brain volume below 600 cubic centimetres, not much larger than an australopith, but some later individuals had brains with a volume of 900 cubic centimetres. Boundless World History. Authored by: Boundless. Located at: https://www.boundless.com/world-history/textbooks/boundless-world-history-textbook/. License: CC BY-SA: Attribution-ShareAlike The road to humanity was a long one, however. Nearly 4 million years later, our ancestors were still very ape-like. Lucy, a famous 3.2-million-year-old human ancestor discovered in Ethiopia, had a small, chimp-sized brain and long arms that suggest her species still spent a lot of time up trees, perhaps retreating to the branches at night as chimps still do. But she did have one defining human trait: she walked on two legs.

Human evolution | History, Stages, Timeline, Tree, Chart

Given Darwin’s reluctance to discuss human evolution in The Origin why did he then decide to publish an account of the topic in 1871? By this time several other scientists, including Thomas Huxley and Ernst Haekel, had expanded Darwin’s theories to the human species. In the meantime Darwin had published on fertilisation of orchids, climbing plants and variation in domestic species. All the while, of course, being limited to a few hours work a day due to ill health; if he had been well The Descent would probably have come out sooner. Virtually every section in the first part of The Descent of Man foreshadows an area of anthropology or biology that has independently flowered since; and in this way, Darwin wrote much of the agenda that was to be followed by paleoanthropology and primatology over the next century and a half’ Debate over the definition of which fossil remains represent modern humans, given these disparities, is common among experts. So much so that some seek to simplify the characterization by considering them part of a single, diverse group.

Darwin was clearly thinking about human evolution before The Origin was published. Famously though, the only mention the topic got in the book was: ‘light will be thrown on the origin of man and his history’. This is perhaps biology’s greatest understatement and most tantalising cliff hanger. Humans took a leap in tool tech with the Middle Stone Age some 300,000 years ago by making those finely crafted tools with flaked points and attaching them to handles and spear shafts to greatly improve hunting prowess. Projectile points like those Potts and colleagues dated to 298,000 to 320,000 years old in southern Kenya were an innovation that suddenly made it possible to kill all manner of elusive or dangerous prey. “It ultimately changed how these earliest sapiens interacted with their ecosystems, and with other people,” says Potts.