Evolutionary Theories and Speciation 4.6.3.1, 4.6.3.2

Question 1

What are species?

Answer 1

organisms that can reproduce to produce fertile offspring

Question 2

Why was Darwin’s book On the Origin of Species controversial?

Answer 2

• natural selection challenged the idea God made all animals and plants
• wasn’t enough evidence to convince many scientists
• mechanism of inheritance and variation wasn’t known until 50 yrs after published.

Question 3

How does speciation occur?

Answer 3

• geographic isolation(barrier)
• separate gene pools, no interbreeding the 2 new population
• variation due to mutation
• different biotic/abiotic factors/selection factors
• different reproductive success/ organisms survive and reproduce
• alleles passed on
• geographic barrier removes
• new species have been created and cannot breed together-called speciation.