Evolution occurs when advantageous traits help individuals survive and reproduce successfully, with those traits being passed along through generations and gradually becoming more widespread among a population over time.
Human fossil records demonstrate our ancestry’s transition from apes. This timeline below highlights key stages in their journey towards becoming humans as we know them today.
Stage 1: Paranthropus
Early humans first appeared in Africa but eventually spread across the globe. As they experienced different climate conditions, their physical adaptations changed to meet them – such as bipedalism, larger brain size, reduced sexual dimorphism and group selection theory that suggests altruist groups may outshout others more readily and survive and reproduce more successfully.
Human evolution began about seven million years ago. Since then, over 20 early hominin species have existed – some more famous than others and some even going extinct; those that survived have gone through four distinct stages of development.
Early hominins evolved as fully upright bipeds using their arms for support on the ground rather than gripping branches, like most primates do today. Furthermore, they lost features seen in extant apes that make them adept tree climbers, such as grasping feet. These early hominins are known as Australopithecus and lived 2.9 to 1.2 million years ago during Pliocene and Middle Pleistocene periods of earth’s history.
Mary Leakey made headlines for discovering Paranthropus robustus at Olduvai Gorge in Tanzania in 1959: the “Nutcracker Man.” OH 80 is unique among Paranthropus fossils as its postcranial remains are connected with taxonomically identifiable craniodental remains that are taxonomically distinct.
OH 80’s skull and teeth suggest it regularly consumed hard foods such as nuts, roots and tough leaves and stems; however, P. boisei teeth show more wear patterns similar to fruit-eaters than hard-food eaters; therefore it is unlikely they regularly consumed these kinds of items.
Stage 2: Homo habilis
Louis Leakey and Mary made one of the earliest discoveries of hominid fossils at Olduvai Gorge in Tanzania, when they recovered stone tools predating themselves at that site and Mary exclaimed “man is the toolmaker!” Zinjanthropus boisei (“Dear Boy” or “Nutcracker Man”) made these tools, while earlier herbivorous versions would not have had the ability to do so. Leakey recognized the cranial capacity of these hominins who created these tools as being more evolved, leading him to name them Homo habilis, or “Handy Man.” Fossils of this early human stage can be found at sites including Hadar and Omo in Ethiopia (along with possible Koobi Fora remains) as well as Swartkrans and Sterkfontein in South Africa.
Homo habilis was, like many early hominids, an omnivorous scavenger who relied on collecting wild plant foods and hunting small animals opportunistically to supplement his or her diets. There is evidence of butchering and meat consumption; cutting marks on bones suggest this began 2.6 million years ago.
Homo habilis is our oldest human ancestor; however, some specimens initially classified as Homo habilis have recently been assigned to other species (Homo rudolfensis and Kenyanthropus gautengensis) due to similarities with more primitive australopithecines. Thus a clear link between these two will likely only become evident once additional fossil discoveries have been unearthed.
As Homo sapiens became increasingly dominant, group-mindedness seems to have increased significantly, evident by sharing of food caches and tools buried and used. This may reflect an evolving form of “cultural transmission”, similar to what occurs among great apes – where adult chimpanzees or orangutans pass along behaviors they learned as children to their offspring.
Stage 3: Homo erectus
Homo erectus (or upright australopithecus), commonly referred to as upright man or “upright australopithecus,” was an extinct human ancestor that used tools and other forms of technology in order to obtain food. Homo erectus marked an evolutionary step away from great apes by full-time bipedalism with increased brain size, advanced bone development for tool making capabilities, and dexterous tool use and hunting abilities.
Homo erectus fossil remains have been discovered across Africa and Asia, where these early humans lived for at least 2 million years. Their skulls feature prominent bony brow ridges known as supraorbital tori which gave these early humans their distinctive heads shape.
Homo erectus fossils differ significantly from Australopithecus remains in that they do not display features related to climbing. Instead, their long limbs and narrower pelvis allowed them to walk more quickly over ground instead of swinging from tree branch to tree branch.
Fossils of Homo erectus indicate that these early humans were capable of hunting meat and other animals for sustenance, gathering fruit, honey and underground tubers from trees for food, as well as hunting other humans to keep themselves warm during colder climates. Homo erectus proved an extremely successful and adaptable species; many members may have become our species over time.
Homo erectus fossils dating to 2.0 to 1.7 million years ago have been found at Olduvai Gorge and Koobi Fora in Kenya, though other fossils from these sites may belong to H. erectus or another species; for instance a jaw fragment found near Mauer in Germany could belong to either species but some scholars consider it part of an entirely separate one called Homo heidelbergensis.
Stage 4: Homo heidelbergensis
Homo heidelbergensis lived between 300,000 and 800,000 years ago in Africa and Europe and left fossils that have been identified as this species. Their fossils have been discovered both areas. As one of the earliest hominin species that evidence of fire can be found, they may have developed symbolic cultures or an ability to anticipate changes in their environments – these likely evolved alongside larger brains as coordination of fine hand movements required to use stone tools required a great deal of brain power; once achieved this allowed intellects to anticipate changing environments to protect organisms against their effects while protecting organisms against effects like abiotic pressures and protect organisms against their effects on organisms from potential impacts that would cause harm from changing environments or pressures on organisms.
Heidelbergensis had an elongated body shape characteristic of humans living in cold climates to reduce loss of heat through their head. Their skulls were more robust than those found among Homo erectus but less slender than modern humans, according to fossil evidence. Their tools included thin yet heavily flaked flint bifaces used for tool making; additionally they hunted large animals such as rhinoceroses and bears with cut marks found at sites such as Boxgrove in England.
Heidelbergensis is commonly accepted to be the last common ancestor between Neanderthals and modern humans, with evidence of fire control and construction of freestanding structures such as huts in some locations. Their diet likely included fruit, vegetables, meat and fish; they hunted and butchered large animals such as rhinoceroses, hippotamuses, deer and horses for which fossil evidence of Heidelbergensis attest to their ability.
Stage 5: Homo sapiens
Homo sapiens (the “wise man”) is the species to which all modern humans belong. We belong to the order Primates alongside other hominids like chimpanzees and bonobos; their evolution over time involves gradual changes. Evolution can also be known as biological variation or natural selection. Through this process, different kinds of animals and plants come into existence before eventually dying off again – those that survive will eventually become dominant species within their ecosystems. People that fail to survive and reproduce will eventually leave a population and form new species; those that remain are then classified as new species; further natural variations may lead to even more distinct forms of the same animal or plant species. Human evolution began millions of years ago and has taken many stages before reaching our present form.
Homo habilis is the fourth stage in human evolution and lived between 1.8 to 2.5 million years ago, using stone tools for food gathering and hunting small game. Due to coordinating fine hand movements for tool use, their brain size increased. Homo heidelbergensis then developed symbolic culture as well as more complex stone tools than Homo erectus did.
Homo sapiens is the final step on humanity’s evolutionary timeline and evolved in Africa before migrating across the world. Their name, which translates to Latin for “wise man,” refers to their ability to think critically and innovate using technologies like fire and stone tools to online casinos where you can play online poker on any of the websites reviewed on the https://centiment.io; additionally, during this period they began living in purpose-built shelters.