Humans share many traits with primates, such as these Barbary macaques, including excellent vision and great dexterity. Everyone reading this blog is a primate. We hear it all he time: Humans are primates. But what does that really mean?
What do we have in common with a baboon? Or a creepy aye-aye? Or even our closest living relative, the chimpanzee? These are simple questions to answer from a genetic perspective—humans share more DNA with lemurs, monkeys and apes than they do with other mammals. Genetic research of the last few decades suggests that humans and all living primates evolved from a common ancestor that split from the rest of the mammals at least 65 million years ago. But even before DNA analyses, scientists knew humans belong in the primate order.
Compare and contrast the evolution and characteristics associated with the various Homo species: Homo habilis, erectus, and sapiens. The human genus, Homo , first appeared around 2. For many years, fossils of a species called Homo habilis were the oldest examples in the genus Homo , but in , a new species called Homo gautengensis was proposed that may be older, although it is not well accepted.
In comparison to Australopithecus africanus , H. However, H. The name H. It is believed to have originated in East Africa and was the first hominin species to migrate out of Africa.
Fossils of H. Its degree of sexual dimorphism was less than earlier species, with males being 20 to 30 percent larger than females, which is close to the size difference seen in our species. Longer, downward-facing nostrils allow for the warming of cold air before it enters the lungs and may have been an adaptation to colder climates. Artifacts found with fossils of H. A number of species, sometimes called archaic Homo sapiens , apparently evolved from H.
These archaic H. They differed from modern humans by having a thick skull, a prominent brow ridge, and a receding chin. Some of these populations survived until 30,—10, years ago, overlapping with anatomically-modern humans. Homo sapiens neanderthalensis Tools : The Homo sapiens neanderthalensis used tools and may have worn clothing. There is considerable debate about the origins of anatomically-modern humans or Homo sapiens sapiens.
As discussed earlier, H. The multiregional hypothesis holds that humans first arose near the beginning of the Pleistocene two million years ago and subsequent human evolution has been within a single, continuous human species. This species encompasses archaic human forms such as Homo erectus and Neanderthals as well as modern forms, which evolved worldwide to the diverse populations of modern Homo sapiens sapiens.
The hypothesis contends that humans evolve through a combination of adaptation within various regions of the world and gene flow between those regions. Proponents of multiregional origin point to fossil and genomic data and continuity of archaeological cultures as support for their hypothesis.
The primary alternative hypothesis is the recent African origin of modern humans, which holds that modern humans arose in Africa around ,—, years ago, moving out of Africa around 50,—60, years ago to replace archaic human forms with limited interbreeding: at least once with Neanderthals and once with Denisovans. Privacy Policy. Skip to main content.
Search for:. The Evolution of Primates. Characteristics and Evolution of Primates All primates exhibit adaptations for climbing trees and have evolved into two main groups: Prosimians and Anthropoids. Learning Objectives Identify key characteristics of primates. Key Takeaways Key Points All primates are descended from tree-dwellers, exhibiting adaptations which allow for tree climbing that include: a rotating shoulder joint, separated big toes and thumb for grasping, and stereoscopic vision.
True primates, ancestral to prosimians, first appear in the fossil record in the Eocene epoch around 55 million years ago; they were similar in form to lemurs. Anthropoids ancestral to both Old World and New World monkeys appear in the fossil record in the Oligocene epoch around 35 million years ago.
Anthropoids ancestral to apes appear in the Miocene epoch around 25 million years ago. Apes are divided into two main groups of hominoids: lesser apes or hylobatids gibbons and siamangs and great apes Pongo : orangutans, Gorilla : gorillas, Pan :chimpanzees, and Homo : humans.
Key Terms dimorphism : the occurrence in an animal species of two distinct types of individual adaptive radiation : the diversification of species into separate forms that each adapt to occupy a specific environmental niche. Early Human Evolution Modern humans and chimpanzees evolved from a common hominoid ancestor that diverged approximately 6 million years ago.
Learning Objectives List the evolved physical traits used to differentiate hominins from other hominoids. Key Takeaways Key Points Modern humans are classified as hominins, which also includes extinct bipedal human relatives, such as Australopithecus africanus , Homo habilis , and Homo erectus.
Few very early prior to 4 million years ago hominin fossils have been found so determining the lines of hominin descent is extremely difficult. Within the last 20 years, three new genera of hominoids were discovered: Sahelanthropus tchadensis , Orrorin tugenensis, and Ardipithecus ramidus and kadabba , but their status in regards to human ancestry is somewhat uncertain.
Key Terms hominin : the evolutionary group that includes modern humans and now-extinct bipedal relatives hominoid : any great ape such as humans belonging to the superfamily Hominoidea. Early Hominins The hominin Australopithecus evolved 4 million years ago and is believed to be in the ancestral line of the genus Homo.
Learning Objectives Describe the physical characteristics of the Australopiths and compare them to those of modern humans. Key Takeaways Key Points The early hominin Australopithecus displayed various characteristics which show more similarity to the great apes than to modern humans: great sexual dimorphism, small brain size in comparison to body mass, larger canines and molars, and a prognathic jaw.
Australopithecus africanus lived between 2 and 3 million years ago and had a larger brain than A. The gracile australopiths had a relatively slender build and teeth that were suited for soft food and may have had a partially carnivorous diet, while the robust australopiths probably ate tough vegetation.
Key Terms dentition : the type, number and arrangement of the normal teeth of an organism or of the actual teeth of an individual sexual dimorphism : a physical difference between male and female individuals of the same species bipedalism : the habit of standing and walking on two feet. Genus Homo The human genus Homo , which includes modern humans as well as extinct human relatives, appeared around 2. Learning Objectives Compare and contrast the evolution and characteristics associated with the various Homo species: Homo habilis, erectus, and sapiens.
Key Takeaways Key Points Homo erectus , appearing 1. Humans, however, also possess many unique characteristics and are therefore classified within a unique subgroup of the Great Apes called the hominins.
The Australian Museum respects and acknowledges the Gadigal people as the First Peoples and Traditional Custodians of the land and waterways on which the Museum stands. Image credit: gadigal yilimung shield made by Uncle Charles Chicka Madden. This website uses cookies to ensure you get the best experience on our website. Learn more. Mammal diversity The first mammals evolved about million years ago. Mammal features All mammals including humans have the same distinctive features. These include: fur or hair growing from the skin mammary glands that, in females, produce milk for feeding the young three bones the malleus, incus and stapes in the middle ear for transmitting sound to the inner ear a single bone the dentary on each side of the lower jaw.
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