Flashcards
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.
What happens to children who are born with mutated DNA?
They develop a random new trait that neither of their parents have.
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
One of the rules of natural selection is that the longer a species lives in an environment the __________
One of the rules of natural selection is that the longer a species lives in an environment the …
more fit for its environment it becomes.
What did Australopiths most likely use to carve the meat off of the bones of the animals they scavenged?
Tools (such as the stone flake).
What is the name for the era of human existence that began when humans began to use stone tools?
The Paleolithic Era / The Old Stone Age.
A species of human is known as a ______.
Hominin
One of the rules of natural selection is that when a species’ environment changes …
One of the rules of natural selection is that when a species’ environment changes …
it causes that species to evolve OR go extinct
What are the six of the key characteristics of a Homo sapiens?
1.) Bipedalism
2.) Our Bodies
3.) Large Brains
4.) Use of Tools
5.) Shelters and Use of Fire
6.) Use of Symbols
What is natural selection?
The process through which species tend to develop traits that make them better fit for the environments they live in.
True or False - Other than being partially bipedal, all of the earliest hominins had almost all of same characteristics as modern-day chimpanzees.
True
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.
What makes a species of human a member of the genus Homo?
Totally Bipedal
Large Brain (relative to their body size)
Use of Tools
Our Bodies (or at least most of its characteristics - especially small teeth & short jaw/face)
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.
A random DNA mutation can give a child a helpful trait that makes them better fit for their environment.
What three things makes a species better for fit for their environment?
Better able to find food, avoid predators, and resist disease.
What trait did all of the earliest hominins probably have that made them distinct from “CHLCA”?
Partial bipedalism
What three activities did the first hominins probably spend 86% of their day doing?
Eating/foraging, resting, and sleeping
What five types of people are experts on Homo sapiens?
Historians
Archaeologists
Biologists
Anthropologists
Paleoanthropologists
How were Australopiths different from earlier hominins?
They were, on average …
1.) 1 ft. taller
2.) Had bigger brains
3.) More bipedal
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)
How many other individuals did the earliest hominins live in groups with?
About 50-55 others.
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.
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 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 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.
