Cambrian Explosion Flashcards
What was the Cambrian explosion?
A diversification of life that occurred in a (relatively) short period of time
How long was the Cambrian period?
55 million years
What appeared during the Cambrian period?
The early forms of most animal groups appeared in this time
What is the evolution of the horse?
Hyracotherium Mesohippus Merychippus Pliohippus Equus
What is the genus of a human?
Homo
When do scientists estimate the first homo to have appeared?
2,2 mya
Where did the first homo appear?
In Africa
What was the first homo species?
Homo habilis
What other similar species did homo habilis live with?
Australopithecus
What is Australopithecus?
A bidpedal primate with both ape-like and human-like characteristics
Why did homo habilis have more skill in making tools than Australopithecus?
They had a larger brain capacity
What homo species came after homo habilis?
Homo erectus
What were homo erectus like?
They had large upright bodies
They resembled modern humans more an Australopithecus
What did homo erectus do?
They were probably the first hominins to migrate from Africa via Europe and Asia
What species are considered to be the direct ancestors of modern humans?
Homo sapiens
What is the brain capacity of Homo sapiens?
1400 cm^3
Why have modern humans not become extinct like other hominins?
Their large brain capacity has allowed them to change their environment to suit their needs
What are living fossils?
Life forms that have changed very little over millions of years
What are three examples of living fossils?
Coelacanth
Cycads
Turtles
What is the coelacanth?
A species of fish
Why is the coelacanth thought to be a living fossil?
It was thought to have become extinct 70 mya
Many have since been found off the South African coast
What is special about the coelacanth?
It thought it be one of the transitional forms between fish and terrestrial animals
Why is the coelacanth thought it be one of the transitional forms between fish and terrestrial life forms?
Its internal organs resemble those of the first land animals
Its fins are also thought to be in the first stage of developing into legs
