Flashcards
What are the five characteristics of a reliable secondary source?
1.) Author is an expert on the topic
2.) The information the author shares is likely to have happened.
3.) The information the author shares is supported by reliable sources
4.) The information the author shares has no bias
5.) The information the author shares is corroborated.
What trait did all of the earliest hominins probably have that made them distinct from “CHLCA”?
Partial bipedalism
True or False - Other than being partially bipedal, all of the earliest hominins had almost all of same characteristics as modern-day chimpanzees.
True
Around 10 MYA, what began to change to forested regions of Central and Eastern Africa?
Some of the forested regions began to be replaced by grasslands and a savanna environment emerged.
What are the key features of savanna grasslands?
- Warm temperatures
- Tall coarse grasses (up to 3-6ft. tall)
- Moderate rainfall
- Seasonal droughts
- Open plains with few trees
- Lots of mammals (especially predators)
Why did “CHLCA” (Chimpanzee-Human Last Common Ancestor) struggle to avoid predators when crossing the grasslands?
1.) Tall grasses made it hard to spot predators
2.) Walking on your knuckles is not efficient/fast for traveling long distances
Why did “CHLCA” (Chimpanzee-Human Last Common Ancestor) struggle to bring food back from other forests?
It walked on all fours and therefore couldn’t carry food back
Why did the mutation of partial bipedalism make CHCLA better able to navigate savanna grasslands?
1.) Allowed it to stand up and stop predators over tall grasses.
2.) Allowed it walk on two legs, which helped it travel longer distances quicker
Why did the mutation of partial bipedalism make CHCLA better able to bring food back from other forests?
Partial bipedalism allowed it to use its arms to carry food instead of walk.
Why didn’t the first hominins evolve to be fully bipedal?
The first hominins still lived in a mostly forested environment and much of the available food was located up in trees.
Being bipedal made it harder to easily climb trees and get food.
What three activities did the first hominins probably spend 86% of their day doing?
Eating/foraging, resting, and sleeping
How many other individuals did the earliest hominins live in groups with?
About 50-55 others.
How were Australopiths different from earlier hominins?
They were, on average …
1.) 1 ft. taller
2.) Had bigger brains
3.) More bipedal
Why did the Australopiths evolve to have the new traits they did?
As the savanna increased - being taller, bigger brained, and more bipedal helped our ancestors better hide and avoid predators as they crossed savanna grasslands.
What did Australopiths do to get enough food now that they were more bipedal and less capable of getting food in trees?
They scavenged meat off of the bones of animals killed by savanna predators.
