Topic 6 - Speciation

Question 1

What is a species?

Answer 1

A species is a group of similar organisms that can reproduce to give fertile offspring

Question 2

What is speciation?

Answer 2

Speciation is the development of a new species

Question 3

Why does isolation cause speciation?

Answer 3

1) Conditions on either side of a physical barrier (that caused isolation) are slightly different
2) Each population shows variation due to a wide range of alleles
3) In each population individuals with characteristics making them better adapted to their environment have a better chance of survival and so are more likely to breed successfuly
4) So the alleles controlling the beneficial characteristics are more likely to be passed on
5) Eventually individuals will have changed so much they can’t breed to produce fertile offspring

Question 4

What did Wallace do?

Answer 4

Alfred Russel Wallace independently proposed the theory of evolution by natural selection. He published joint writings with Darwin in 1858 which prompted Darwin to publish On the Origin of Species (1859) the following year.

Question 5

Why is Wallace important?

Answer 5

Wallace worked worldwide gathering evidence for evolutionary theory. He is best known for his work on warning colouration in animals and his theory of speciation.
Alfred Wallace did much pioneering work on speciation but more evidence over time has led to our current understanding of the theory of speciation.