Theory Of Natural Selection

Question 1

Four key observations Darwin made

Answer 1

-organisms produce large numbers of offspring
-no two individuals are identical with variation in the characteristics of members of the same species existing
-offspring generally look like their parents-characteristics can be passed from one generation to the next
-individuals best adapted to their environment are more likely to survive

Question 2

Steps of natural selection

Answer 2

-variation exists within a population in their phenotypes from mutation and sexual reproduction
-different environment have different selection pressures which are any environmental factors that determine which individuals of a species survive
-individuals with advantageous alleles most suited to their environment are more likely to survive and reproduce and pass on their advantageous alleles on to their offspring
-over time the proportion of the population with the advantageous alleles will increase leading to evolutions and the formation of a new species

Question 3

What is a selection pressure

Answer 3

Any environmental factor that determines which individuals of a species survive

Question 4

What did Wallace do

Answer 4

Independently came up with the idea of evolution by natural selection and published papers with Darwin on tbis

Question 5

What are extremophiles

Answer 5

Organisms which can survive in extreme conditions (eg temperature, pH, salt level and pressure)

Question 6

What is convergent evolution

Answer 6

The process whereby organisms that are not closely related, independently evolve to have similar features as a result of having to adapt to similar environments with similar selection pressures