Evolution and Selective Breeding

Question 1

(DON’T NEED)Why was the theory of evolution rejected by most people?

Answer 1

• It went against the religious belief that God created life
• Darwin couldn’t explain how the useful characteristics were passed on from a parent to an offspring because he didn’t know anything about genes or mutation
• There wasn’t enough evidence to convince people

Question 2

(DON’T NEED)What was Jean-Baptiste Lamarck’s theory?

Answer 2

Changes that an organism gets during its lifetime are inherited by its offspring

Question 3

What is selective breeding?

Answer 3

• From your existing stock, pick the ones with the characteristics you want
• Breed them together
• From their offspring choose the ones with the characteristics you want and breed them together
• Continue for several generations and eventually all the offspring will have the characteristics

Question 4

What is selective breeding used for?

Answer 4

• Animals that produce more meat or milk
• Crops with disease resistance
• Dogs with desired characteristics

Question 5

What are the problems with selective breeding?

Answer 5

• It reduces the gene pool (the number of different alleles in a population). This is because the farmer picks from the “best” which have all the same alleles. So if there is a disease that can kill an individual, there’s not much variation in the rest of the population so the rest of the population may die from the disease too.
• Inherited defects
• Inbreeding, some breeds are particularly prone to disease