Chapter 9.3 A Mechanism For Evolution: Natural Selection

Question 1

What does the term ‘descent with modification’ highlight?

Answer 1

It highlights the important idea that all life that exists today have descended from shared ancestors.
-The shared characteristics observed in organisms led them to conclude that all organisms descended from an ancestor that lived in the past

Question 2

What is accumulation?

Answer 2

The process of alleles or traits gradually becoming more common over generations

Question 3

How does natural selection occur and what does this result in?

Answer 3

It occurs when selection pressures in the environment give an advantage on a specific phenotype and enhance its survival and reproduction.
-This results in changes in allele frequencies in the gene pool of a population

Question 4

How are alleles expressed through an organisms?

Answer 4

Through phenotypes, also known as traits

Question 5

What is an adaptation?

Answer 5

An inherited trait that allows an individual to survive and reproduce

Question 6

If a phenotype is an advantage towards the environment what will happen to that trait?

Answer 6

It will be more likely to survive and have offspring

Question 7

If a phenotype is an disadvantage towards the environment what will happen to that trait?

Answer 7

It will be less likely to survive and have fewer offspring