B2f-natural Selection

Question 1

What is Darwin’s theory of evolution?

Answer 1

-organisms in a species show wide variation
-compete for limited resources
-best adapted will survive(survival of the fittest)
-inheritance of successful adaptations
(Pass on adaptations to offspring)

Question 2

What are adaptations controlled by?

Answer 2

Genes

Can be passed on to next generation

Question 3

What is speciation?

Answer 3

The development of a new species

Question 4

What is evolution?

Answer 4

When groups of organisms change over time

Question 5

How does reproductive isolation cause speciation?

Answer 5

Same species change

They cant interbreed to produce fertile offspring

Question 6

How is reproductive isolation caused by geographic isolation?

Answer 6

• physical barrier divides population of species
• different mutations creates new features
• natural selection
• conditions on each side different
• individuals will have different features
• wont be able to breed together

Question 7

Why was the theory of natural selection controversial at first?

Answer 7

-went against religious beliefs about how life on earth developed(didn’t need a creator)
-darwin couldn’t explain why new characteristics appeared or how they were inherited
-not enough evidence to convince other scientists
Not many other studies had been done

Question 8

Why is the theory of natural selection now widely accepted?

Answer 8

It explains a wide range of observations

It has been discussed and tested by a wide rang of scientists

Question 9

What was lamarcks theory?

Answer 9

• if a characteristic was used a lot then it would be more developed
• these acquired characteristics could be passed on to offspring

Question 10

Why was lamarcks theory discredited?

Answer 10

It didn’t have a genetic basis

Question 11

How has the theory of natural selection developed?

Answer 11

• DNA discovered
• new adaptations arise because of mutations
• successful adaptations passed on in genes that parents contribute