The History of Human Evolution

Important Terms Primate Hominid The order of mammals to which human beings belong Hominid A bi-pedal (up-right walking) primate All humans are primates, but humans are the only hominid

Primates First appeared ~ 65 million years ago (YA) 8-20 million years ago the ancestral lines of hominids and apes split 4 million YA the first bi-pedal hominid appears

Australopithecus Afarensis “Lucy” First skeletal evidence of bi-pedalism found fossilized remains in the Great Rift Valley of Africa “Lucy” (named after the Beatles song that was playing when she was discovered) was a fully bi-pedal hominid 106 cm (3.5 feet) tall Adult female Pelvic structure of modern woman, but ape like skull (small brain) Challenged previous idea that a large brain was the key to human evolution

Great Rift Valley

“Lucy”

What Lucy might have looked like:

“Lucy” & Us Other than being bipedal, Lucy was certainly more ape like in her behaviour But, being the earliest bipedal hominid she must be part of our family tree

Hominid Diversity As early as 3.5 million years ago there are 3 distinct species of australopithicines: A. Afarensis (Lucy) A. Africanus A. Robustus 2.5 MYA Australopithicus has disappeared from the fossil record

A. Africanus

A. Robustus

Homo habilis (the handyman) Larger brained hominid Omnivorous diet Evidence of tool use and tool making!

Homo habilis

Habilis Tools

Homo Erectus Appeared 1.7 MYA Fully upright walker Increased brain & body Proficient tool maker & user First to control fire! Migrates out of Africa to Asia, Java, Middle East By 1.2 MYA all hominids but homo erectus are extinct 400,000 years ago, other hominids appear

Erectus Tools

Erectus Range

Homo sapiens neanderthalenis Named for the Neander valley in Germany where first fossils were found First appear about 300,000 YA, but by 130,000YA complete Neanderthal characteristics in place Very successful ice-age survivors

Neanderthals

What Happened to Neanderthals? Nenaderthals disappear about 30,000 YA Some evidence they did interbreed with modern humans Still others believe they survived and emerged as leaders of the Soviet Union - but that also became extinct in the 1990s