A diagram of probable primate evolution. Fig Prosimians non-anthropoid primates For images of lemurs, lorises, etc. Hominoids : hominids plus apes Fig Hominids walked upright for two million years without a substantial increase in brain size. It is a common misconception that all traits evolved at the same time. Mosaic evolution - different features evolved at different rates.
This link will take you to a page that has a paragraph or 2 about each of these species. Sahelanthropus tchadensis - newest discovery - between 6 and 7 myo. Not certain if it is a hominid or more kin to apes. Face much flatter but not certain at this point if it was fully bipedal. Significant also because found much further west in Africa than any other hominid fossil.
See an article and links here and here. See a great website on this new species here. Ardipithecus ramidus Australopithecus ramidus 4. Australopithecines : southern ape The First Humans: 4.
Map of Africa and sites of fossil finds. Map with skulls. Meanwhile, the hominoids refer to a branch of Old World, tailless simians native to Africa and Southeast Asia. Anthropoids are also known as simians while hominoids are also known as apes. Moreover, anthropoids belong to the infraorder Simiiformes while hominoids belong to the superfamily Hominoidea. Anthropoids include the infraorder of catarrhines Old World monkeys and apes and the infraorder of platyrrhines New World Monkeys while hominoids include the family of Hylobatidae the lesser apes , the family of Hominidae the greater apes and the genus Homo humans.
Anthropoids originated forty million years ago, giving rise to New World monkeys through the colonization in South America and twenty-five million years ago, Old World monkeys and apes split. Around known species of monkeys live in the world while around 23 known species of apes live in the world.
While monkeys have a small body with a quadrupedal position, apes have a comparatively large body with upright posture. Monkeys have a narrow chest, while apes have a broader chest. The limbs of monkeys have an equal length while the upper limbs are longer in apes and lower limbs are longer in humans. Furthermore, monkeys have narrow shoulders, while the apes have stronger and flexible shoulders. The arms of the monkey cannot be straightened at the elbow while the wrist and the forearm can achieve a limited range of movements.
In comparison to this, the arms of the ape fully straightened at the elbow, while the wrist and the forearm can achieve a wide range of movements. New World monkeys have a long and flexible tail, Old World monkeys have short tails, while the apes do not have a tail.
Monkeys run along the tops of the trees by jumping with the use of tail for the balance, while the apes swing from branch to branch.
Whereas monkeys have a small brain, apes and humans have comparatively a large and complex brain. Monkeys rely on the smell, while apes rely on vision. Moreover, monkeys have lower intellectual capabilities, while the apes have a complex social-behavioural system and higher cognitive skills.
New World monkeys evolved forty million years ago in South America. They have a smaller body size with the quadrupedal position, narrow chest and shoulders, and a long, flexible tail. On the other hand, Old World monkeys and apes evolved twenty-five million years ago. Basically, hominoids are apes and humans. However, they have a large body with an upright position and a significantly large and complex brain. They do not have a tail.
Meanwhile, humans show the highest evolutionary level with the highest intellectual capabilities. Hominid — the group consisting of all modern and extinct Great Apes that is, modern humans , chimpanzees, gorillas and orang-utans plus all their immediate ancestors.
Hominin — the group consisting of modern humans , extinct human species and all our immediate ancestors including members of the genera Homo , Australopithecus , Paranthropus and Ardipithecus.
It was therefore a very useful term to designate the line leading to modern humans and was used when referring to various members of our human evolutionary tree. This new terminology is being used in many scientific journals already, and it is only a matter of time but possibly many years before everyone catches up to using the new term.
The problem for students and teachers is that a lot of texts still use the old system and many internet sites also haven't caught up, even those of many reputable scientific establishments. By international convention, certain word endings are used for specific taxons or levels within this classification.
These formal names are then abbreviated to give the common names hominid, hominine and hominin respectively. The name changes that have occurred have arisen due to changes in the way humans, chimpanzees, gorillas and orang-utans are classified. For example, it was once thought that apes should be divided into three different groups families.
In this old scheme, humans were seen to be so different to other apes that we should be placed into our own distinct family, the Hominidae or hominids. Over time, biological classifications change due to improved techniques and better knowledge about the biology and the evolutionary relationships of different living things.
Now, with their better knowledge, scientists have revised their classifications to develop more up-to-date evolutionary trees. In this scheme, only two families are recognised with all the Great Apes including humans placed into the same family, the Hominidae or hominids.
The next branching of this evolutionary tree divides the orang-utans into one subfamily and all the remaining Great Apes into another subfamily. Then at the tribe level, gorillas, chimpanzees and humans separate onto different branches of the evolutionary tree with humans in the Hominini or hominin branch.
0コメント