Introduction to Natural Selection

Question 1

Summary of Darwin’s theory of evolution by natural selection

Answer 1

Many varied individuals are produced
Variation is inherited
Not all survive - useful traits increase

Question 2

Microevolution

Answer 2

Changes in gene frequency

Question 3

Macroevolution

Answer 3

Formation of new species

Question 4

Why are some species are similar?

Answer 4

Due to descent with modification
from common ancestors

Question 5

A Description of Darwin’s Tree of Life

Answer 5

Evolution is not linear
=> all organisms are equally fit/good at the end of branches

Evolution is not random (as well as fitness) - mutation is

Question 6

What is fitness?

Answer 6

Reproductive success (can be increased)

Question 7

How is fitness increased directly?

Answer 7

By genes that increases reproduction

e.g. peacock’s tail is impractical to eat/survive predation but attracts females to mate to pass down genes

Question 8

How is fitness increase indirectly?

Answer 8

By genes that affect survival

Question 9

The Process of Natural Selection

Answer 9

Darwin preferred differential selection as a term
=> organisms that are best adapted to an environment survive and reproduce more than others

Question 10

1st step of Natural Selection

Answer 10

(1) Overproduction - each species produces more offspring that can survive

Question 11

2nd step of Natural Selection

Answer 11

Variation - each individual has a unique combo of traits

Question 12

3rd step of Natural Selection

Answer 12

Competition - not all survive to adulthood

Question 13

4th step of Natural Selection

Answer 13

Selection - those with the best traits survive and pass on traits to offspring