Human evolution Flashcards
When were humans first grouped with primates?
By Linnaeus when he classified organisms based on their shared morphological traits.
What are some examples of traits that primates share?
A gripping thumb and forward facing eyes (important for climbing trees).
What is evidence for humans as primates?
Molecular evidence from mitochondrial DNA.
How many hominin species are there?
Around 20.
What is the problem with the fossil record for hominins?
It is very sparse and is based on small bones rather than whole skeletons.
What was the earliest adaptation that split humans from other ape ancestors?
The ability to walk on two legs.
What did enlargement of the jaw and molars suggest?
That we were eating a more grain based diet compared to a fruit based diet as we moved to grassland.
What was the evidence for early hominins and upright walking?
There was a shift in position of where the spinal cord meets the skull in comparison to non-upright walking species and adaptations to the femur - it is slanted.
What does the reduction in canine length suggest?
The increase in biparental care and increased monogamy as these are features associated with sexual selection.
Why in more recent times has the jaw sized of hominins decreased?
A more processed diet - such as processed grains, cooking food and relying on meat and hunting rather than gathering grains.
What was the first evidence of tool making?
3.4 million years ago - chimpanzees.
What are some of the traits that characterise the homo species?
Larger brains, increased adaptations to bipedalism, smaller molar teeth and jaws.
How could social evolution have driven increased brain size?
Toddlers are seen to have communicate a lot more than apes of the same relative age and it is thought that human brains have adapted to cope with more complex social interactions.
When was the first migration out of Africa by Homo erectus?
1.8 million years ago.
When did the H. Heidelbergensis spread to Europe and Asia?
Around 800,000 years ago. They were seen to use more sophisticated tools than previously that were used to cut food and plant material, they were seen to have larger brains as well.
