Bio Assumption 1- Evolutionary Influences

Question 1

Describe Darwin’s theory of natural selection

Answer 1

Darwin assumes that only a small proportion of each generation survives to reproduce and that offspring are not identical. This means that at least some of the variation is heritable. Darwin also believed that some of these characteristics give animals an advantage over others in the ability to survive and reproduce. These are known as adaptive characteristics.

Question 2

How does Darwin’s theory of natural selection explain a phobia of snakes and spiders?

Answer 2

A feat of snakes and spiders is adaptive because the are highly poisonous and can kill with one bite. People with a predisposed fear of spiders are more likely to avoid them; therefore they are less likely to get bitten and die. This means that the individual is more likely to live longer and reproduce. This can cause the gene to get passed onto the next generation.

Question 3

Describe the EEA

Answer 3

Environment of evolutionary adaptiveness (EEA) is the environment that humans are adapted to, therefore any adaptive behaviours we have are due to the pressures that our ancestors faced. However, not all behaviours are adapted, only those that will ensure the survival of individuals in a particular environment.

Question 4

How does the EEA explain why humans have big brains?

Answer 4

Brains have evolved in response to the complex social organisation of our species. Those ancestors with more evolved brains would be more likely to be able to form alliances; therefore increase their chances of survival and passing their genes on.