The Early Hominins Flashcards
(157 cards)
What percentage of humans genes are shared with chimpanzees?
98.7%
What does the small genetic difference between humans and chimps result in?
results in enormous differences between us as species
How many species of Homo do we have on this planet?
We are unique – for all our diversity, there is only one species of Homo on the planet – that is us, Homo sapiens
What makes humans unique?
- Habitual bipedalism
- Large brain size (relative to body size)
- Large capacity for planning and problem solving (thinking in the abstract)
- Tool making
- Great social complexity
- Complex language
When did human lineage split from chimp lineage?
Molecular evidence suggests that the lineage that led to modern humans split from the chimp lineage only about 5-7 Mya.
Whats a chimp?
Chimpanzee
What has happened to humans in the 5-7 million years since we split from the chimps?
the human lineage underwent some profound evolutionary changes to bring us to where we are today
Define hominid.
the group consisting of all modern and extinct Great Apes (i.e. modern humans, chimpanzees, gorillas and orang-utans plus their immediate ancestors)
Define hominin
the group consisting of modern humans and extinct species on the human lineage since our divergence with the apes
Why is the hominin lineage confusing?
- It is more of a ‘bush’ with numerous branches than it is a simple linear progression from earliest hominin to modern human
- The dates of the various important fossil discoveries do not reflect the timeline of hominin evolution
- The paucity of fossil evidence in many cases and over certain time periods
- Species are reclassified and renamed
What was Raymond Dart presented with in South Africa in 1924?
the immature skull of a small-brained creature extracted from a South African mine. This was named the Taung child.
What was the first discovery of an early hominin ?
The Taung child
Whats the Taung child?
The skull found by Raymond Dart in 1924 in south africa in a mine.
Why was the Taung child named the Taung child?
It was named the Taung child, after the site where it was found.
What did Raymond Dart call the Taung child?
Australopithecus africanus (“southern ape from Africa“)
Whats the Taung child also known as?
Australopithecus africanus (“southern ape from Africa“)
What was Australopithecus africanus contested to be?
originally this was hotly contested as being a precursor to humans.
What were researchers convinced of about human evolution?
Researchers were convinced humans evolved in Asia (Eurocentric), not Africa (despite little evidence from either region)
What were there preconceived ideas about?
There were preconceived ideas about what characteristics a human ancestor would have.
What did Australopithecus africanus look like?
Some features quite ape-like -
it had a protruding face and small brain.
Other features were not ape-like (e.g. dentition)
What features of Australopithecus africanus were ape like?
protruding face and small brain.
What features of Australopithecus africanus were not ape like?
dentition
What do the anatomical features of Australopithecus africanus show?
Anatomical features (position of the foramen magnum) indicated it walked upright on two legs (bipedal)
Define bipedal.
Walking upright on two legs.