Primate Evolution

Today’s Objectives:

investigate and understand how primates have changed through time, including:– Examining fossil records – Recognizing how adaptations lead to

natural selection

Primates are mammals that have:

Opposable thumbs Large brain Good, stereoscopic vision Ability to brachiate Flexible elbows for hand rotation Grasping feet

Early Primates

Appeared 60-65 million years ago Prosimian

– Small bodies– Lemurs, Tarsiers

Anthropoids– Human-like primates– Evolved in Africa

 Small Insectivore from the end of the Mesozoic Era

Proto-primates

Early Prosimians

  

Smilodectes   (lemur-like family Adapidae   

from the Eocene Epoch)  

Early Monkeys and Apes

  Great Rift Valley system   

(shown in green)  

 India Forcing up the Himalayas

 and the Tibetan Plateau

Hominid Evolution

Hominids developed

5-8 million yrs ago Hominids are bipedal First hominids were in

genus Australopithecus– “Lucy” most famous fossil hominid

More modern hominids were in genus Homo

More recent humans

Homo sapiens (developed 400,000 years ago)

– Neanderthals• Europe arrival (100,000 years ago)

– Cro-Magnon • Europe arrival (40,000 years ago)• Americas arrival (12,000 years ago)

 A schematic showing the spreading of humans in history

The Spreading of early modern man (red) from Africa, based on genetic studies. 

Up to 37 500 YBP

Up to 35 000 YBP

Up to 32 500 YBP

Up to 30 000 YBP

To put Human History into prospective

4.6 billion The Earth forms and is bombarded by meteorites and comets.3.8 billion Years agoReplicating molecules (the precursors of DNA) form.

3.5 billion Years agoUnicellular life evolves. Photosynthetic bacteria begin to release oxygen into the atmosphere.

555 million Years agoMulti-cellular marine organisms are common. The diverse assortment of life includes bizarre-looking animals like Wiwaxia.

500 million Years agoFish-like vertebrates evolve. Invertebrates, such as trilobites, crinoids, brachiopids, and cephalopods, are common in the oceans.

450 million Years agoArthropods move onto the land. Their descendants evolve into scorpions, spiders, mites, and millipedes.

420 million Years agoLand plants evolve, drastically changing Earth's landscape and creating new habitats.

360 million Years agoFour-limbed vertebrates move onto the land as seed plants and large forests appear. The Earth's oceans support vast reef systems.

250 million Years agoThe supercontinent called Pangea forms. Conifer-like forests, reptiles, and synapsids (the ancestors of mammals) are common.

248 million Years agoOver 90% of marine life and 70% of terrestrial life go extinct during the Earth's largest mass extinction. Ammonites are among the survivors.

225 million Years agoDinosaurs and mammals evolve. Pangea has begun to break apart.

130 million Years agoAs the continents drift toward their present positions, the earliest flowers evolve, and dinosaurs dominate the landscape. In the sea, bony fish diversify.

65 million Years agoA massive asteroid hits the Yucatan Peninsula, and ammonites and non-avian dinosaurs go extinct. Birds and mammals are among the survivors.

4 million Years agoIn Africa, an early hominid, affectionately named "Lucy" by scientists, lives. The ice ages begin, and many large mammals go extinct.

130,000 Years agoAnatomically modern humans evolve. Seventy thousand years later, their descendents create cave paintings — early expressions of consciousness.