Primates and the Origins of Homo sapiens
Prologue: what happened to the Ice Age Megafauna?
Ice Age Extinctions: 66 million years after the extinction of the dinosaurs, mammals thrived. Giant elephants existed in
Europe, Asia and North America.
Wooly rhinos and the Irish Elk: rhinos and giant deer roamed the plains of Europe and Asia.
Giant Ground Sloths and Armadillos – South America’s xenarthrans diversify to produce large herbivores, and invade North
America.
Australian Megafauna – giant wombats, giant kangaroos, wolf-like marsupials, giant predatory lizards, giant flightless
ducks.
Island Megafauna – islands evolved distinctive faunas – flightless birds, flightless geese…
Today these things are only known by fossils.
What happened to them?
Climate Change – these are in part driven by regular changes in the earth’s orbit. The shape of the orbit changes on
400,000 and 100,000 year cycles. The orientation of the axis changes in a 23,000 year cycle. The tilt changes on a 41,000-
year cycle.
The megafauna – mammoths, rhinos, giant ground sloths, giant armadillos, sabertooths – they had taken millions of years
to evolve, which means that they had gone through countless climactic shifts. Why was this one different? Something else
must be going on…
Timing of Extinction – ice ages start and end at the same time everywhere in the world. Megafaunal extinctions are
staggered in time. What connects all these things?
An Invasive species – a new species suddenly becomes widespread around 50,000 years ago. 45,000 years ago, it reaches
Australia, 35,000 years ago it reaches Europe and Asia, and 15,000 years ago it reaches the Americas. It then begins to
disperse to islands.
Mass Extinction – in every habitat that this species colonises, the large mammals and other large species such as birds,
lizards and snakes, soon disappear.
What species could do this? A highly specialised species of bipedal primate. Homo sapiens!
Primates and Humans
Primates: moderately diverse (around 350 species). Small and medium sized. Variety of diets – insectivorous, omnivorous,
frugivorous, herbivorous. Primarily arboreal, but some species are terrestrial.
, Prosimians: mostly nocturnal, have wet noses like other mammals. Loris in Asia, bushbaby and galagos in Africa, Lemurs –
major radiation in Madagascar.
Tarsier: looks lemur-like, but DNA shows they re close to humans – have a dry nose like a human. Asian – along with lorises,
colugo, and tree shrews – suggesting that primates originally evolved in Asia. Like monkeys and apes, large-brained and have
a highly mobile upper lip.
New World Monkeys: somehow got from Africa to South America in the Eocene (35 mya). South America has been isolated
since the end of the Cretaceous. Thought to have rafted out of Africa on floating vegetation.
Old World Monkeys: Africa, Asia & Europe. More closely related to apes and humans.
Apes: gibbons, orangs, gorillas, apes & humans. Found in Asia and Africa.
Humans are Apes: within the apes, humans are most closely related to chimps. Large bodied compared to other primates,
lack tail & large brains.
Prologue: what happened to the Ice Age Megafauna?
Ice Age Extinctions: 66 million years after the extinction of the dinosaurs, mammals thrived. Giant elephants existed in
Europe, Asia and North America.
Wooly rhinos and the Irish Elk: rhinos and giant deer roamed the plains of Europe and Asia.
Giant Ground Sloths and Armadillos – South America’s xenarthrans diversify to produce large herbivores, and invade North
America.
Australian Megafauna – giant wombats, giant kangaroos, wolf-like marsupials, giant predatory lizards, giant flightless
ducks.
Island Megafauna – islands evolved distinctive faunas – flightless birds, flightless geese…
Today these things are only known by fossils.
What happened to them?
Climate Change – these are in part driven by regular changes in the earth’s orbit. The shape of the orbit changes on
400,000 and 100,000 year cycles. The orientation of the axis changes in a 23,000 year cycle. The tilt changes on a 41,000-
year cycle.
The megafauna – mammoths, rhinos, giant ground sloths, giant armadillos, sabertooths – they had taken millions of years
to evolve, which means that they had gone through countless climactic shifts. Why was this one different? Something else
must be going on…
Timing of Extinction – ice ages start and end at the same time everywhere in the world. Megafaunal extinctions are
staggered in time. What connects all these things?
An Invasive species – a new species suddenly becomes widespread around 50,000 years ago. 45,000 years ago, it reaches
Australia, 35,000 years ago it reaches Europe and Asia, and 15,000 years ago it reaches the Americas. It then begins to
disperse to islands.
Mass Extinction – in every habitat that this species colonises, the large mammals and other large species such as birds,
lizards and snakes, soon disappear.
What species could do this? A highly specialised species of bipedal primate. Homo sapiens!
Primates and Humans
Primates: moderately diverse (around 350 species). Small and medium sized. Variety of diets – insectivorous, omnivorous,
frugivorous, herbivorous. Primarily arboreal, but some species are terrestrial.
, Prosimians: mostly nocturnal, have wet noses like other mammals. Loris in Asia, bushbaby and galagos in Africa, Lemurs –
major radiation in Madagascar.
Tarsier: looks lemur-like, but DNA shows they re close to humans – have a dry nose like a human. Asian – along with lorises,
colugo, and tree shrews – suggesting that primates originally evolved in Asia. Like monkeys and apes, large-brained and have
a highly mobile upper lip.
New World Monkeys: somehow got from Africa to South America in the Eocene (35 mya). South America has been isolated
since the end of the Cretaceous. Thought to have rafted out of Africa on floating vegetation.
Old World Monkeys: Africa, Asia & Europe. More closely related to apes and humans.
Apes: gibbons, orangs, gorillas, apes & humans. Found in Asia and Africa.
Humans are Apes: within the apes, humans are most closely related to chimps. Large bodied compared to other primates,
lack tail & large brains.
