Evolution

Question 1

Why do we study non-human animals?

Answer 1

Because there are cross-species similarities in brain structure and function, allowing us to use animals as models to understand brain-behaviour relations, mechanisma and neurological disorders.

Question 2

What did Maren et al (1997) find?

Answer 2

Which neuronal systems are key - hippocampal lesions in rats impaired conditioning to contextual cues. Cause amnesia in humans.

Question 3

What are comparative studies?

Answer 3

The study animals’ brains and behaviour, especially that which relates to phylogeny of the brain. Particular species have advantages.

Question 4

What did Clayton (1998) do?

Answer 4

A comparative study - found that the hippocampus is key for learning and memory - it is enlarged in food-storing species and can change size in response to experience = plasticity (e.g. cab drivers study).

Question 5

What is Darwinian theory?

Answer 5

That organisms’ characteristics have precise functions which are selected for, becoming more prevalent, if they increase chances of survival and reproduction.

Question 6

Which animals are part of the hominid family?

Answer 6

Human, gibbon, chimpanzee, gorilla, and orangutan.

Question 7

What is functionalism?

Answer 7

The belief that characteristics of organisms perform useful functions and that the best way to understand a biological phenomenon (behaviour/physiological structure) is to try to understand what its function is.

Question 8

Define natural selection.

Answer 8

The process by which inherited traits that confer a selective advantage become more prevalent in a population.

Question 9

What is a mutation?

Answer 9

A change in genetic information in gametes that can be passed on to offspring, providing genetic variability.

Question 10

Define: selective advantage

Answer 10

A characteristic that permits an organism to produce relatively more offspring.

Question 11

Define: evolution

Answer 11

Gradual change in the structure and physiology of species, generally producing more complex organisms as a result of natural selection.

Question 12

What is significant about the Galapagos islands?

Answer 12

They are geologically young and have a lot of endemic species. Darwin’s finches.

Question 13

Define: genetic drift

Answer 13

The change in frequency of an allele in a population due to random sampling.

Question 14

Define: speciation

Answer 14

The formation of new and distinct species in the course of evolution.

Question 15

What did Huxley (1968) propose?

Answer 15

That birds were descendants of dinosaurs - many species have since been found to be feathered!

Question 16

What were the earliest mammals like?

Answer 16

They were small nocturnal predators that fed on insects from around the Triassic period. They were only a modest success for millions of years, until the extinction of the non-avian dinosaurs 250mya, at which point they diversified - they had the selective advantage of being endothermic.

Question 17

Where did the first hominids appear and what were they like?

Answer 17

Africa, about 5 million years ago, living in dry woodlands, grasslands and the savanna.

Question 18

When did the first hominids leave Africa?

Answer 18

Homo erectus, about 1.7mya, scattering across Asia and Europe.

Question 19

Where and when did Homo sapiens evolve?

Answer 19

East Africa around 100,000 years ago, with some migration to other continents.

Question 20

How much DNA do humans and chimpanzees share?

Answer 20

Almost 99%.

Question 21

How is the human brain different to other hominids’?

Answer 21

It’s larger (over double the volume, with overall body weight about the same) - encephalisation quotient. However this isn’t everything (shrews have a large brain:body ratio but aren’t very clever)
We have a larger neocortex.
Slow maturational processes - neoteny (brains not mature until late adolescence, 4x infant size)

Question 22

Give an example of natural selection.

Answer 22

Grey squirrels can digest acorns (red squirrels can’t), and they carry a virus that is more deadly to red squirrels. Red squirrels also breed less under pressure, meaning that the Eurasian red squirrel has become much rarer since the introduction of grey squirrels.

Question 23

In what ways did the earliest mammals develop before humans appeared?

Answer 23

• Bipedalism
• Opposable thumbs
• Colour vision
• Linguistic abilities.

Question 24

What are the main theories of what makes us human?

Answer 24

• TOM
• Linguistic abilities (although chimps understand word order when using sign language)
• Culture
• Something else?