Hominin Evolution - Hominids and Hominins Aims: Must be able to outline the characteristics of Hominids, Apes and Hominins. Should be able to state the main Australopithecines and their main features. Could be able to compare and contrast the main forms of Australopithecines.

The Hominids Includes: Great Apes and hominins Anatomical features common to all hominoids: No tail Semi-erect or fully erect posture Broad chest, pelvis, and shoulders Relatively long arms and mobile shoulder joints Large brain Australopithecus afarensis Chimpanzee

The Apes Anatomical features and habits: Brachiating (swing underneath from branch to branch) Some mainly ground dwelling and quadrupedal (e.g. gorilla) Arms longer than legs Flattened nose Bony eye ridges No tail Gibbon Chimpanzee Gorilla Orangutan

Hominins Anatomical features and habits: Bipedal with modified feet, thigh bone, pelvis, and spine Large cerebral cortex (forebrain) Reduced canines (and teeth in general) Prominent nose and chin, reduced eye ridges Body hair short or very reduced to assist cooling Highly sensitive skin Complex social behavior Examples: Australopithecus Paranthropus Homo Ardipithecus? Paranthropus boiseiHomo neanderthalensisHomo sapiens Includes modern humans, extinct human species and immediate ancestors.

Early Hominids Since the mid 1990s a considerable number of new, early hominid species have been discovered: Symbol Hominid Age (mya) Sahelanthropus tchadensis Orrorin tugenensis6.0 Ardipithecus ramidus Australopithecus anamensis Kenyanthropus platyops3.5 Australopithecus bahrelghazali Australopithecus garhi2.5 Sahelanthropus tchadensis Kenyanthropus platyops Photos courtesy of: SkullsUnlimited.com

Some Famous Hominin Fossils..

The Australopithecines The main forms are: Australopithecus afarensis Australopithecus africanus Kenyanthropus platyops

There is good fossil evidence that four kinds of hominid lived about 1.8 mya in what is now part of northern Kenya. They foraged in the same area around Lake Turkana. We have no idea how, or if, these different species interacted. Once We Were Not Alone P. boiseiH. habilisH. rudolphensisH. ergaster

Genus Homo Homo sapiens 130,000 yrs ago - Present Africa and western Asia, then global Homo neanderthalensis 150, ,000 yrs ago Europe and western Asia Archaic Homo sapiens 400, ,000 yrs ago Africa, Asia and Europe Homo erectus 1.8 M - 300,000 yrs ago Africa, Asia, Indonesia and possibly Europe Homo habilis 2.4 M M yrs ago Eastern, and possibly Southern Africa Homo ergaster 1.8 M M yrs ago Africa, possibly Western Asia

Genus Homo The main forms are: Homo habilis Homo erectus Homo heidelbergensis Homo neanderthalensis Homo floresiensis Homo sapiens

The Effect of Continental Drift Early primates emerged in a world that was undergoing great change due to continental drift. During the Paleocene and Eocene, the continents were breaking up and taking on their present shapes and positions. Shifting continents affected climates, vegetation, and habitats for the evolving primates. Late Paleozoic 250 million years ago The ancestors of the mammals were still in the early stages of evolving

The Effect of Continental Drift Paleocene-Mid Eocene million years ago Early primates were distributed throughout North America and Europe (because the continents were joined) Primates were absent from Asia until the late Eocene (separated from Europe by Turgai Strait) Turgai Strait Madagascar

The Effect of Continental Drift Later Eocene million years ago North America separated from Europe Europe joined onto Asia and Africa Primates in North America were isolated and evolved without competition New primates emerged in Africa, Asia, Europe: the Old World monkeys, apes and hominids Madagascar

When did they live?

Activity Complete the ‘SKULLS’ activity on the laptops: