Evolution and natural selection

Question 1

What is evolution?

Answer 1

The genetic change in the characteristics of a species over many generations, resulting in the formation

Question 2

What is the outcome of natural selection?

Answer 2

A species gradually becomes better adapted to it’s environment.

Question 3

What is Charles Darwin famous for?

Answer 3

Suggesting natural selection was the mechanism of evolution.

Question 4

What is natural selection?

Answer 4

The process which random evolutionary changes are selected for by nature in a consistent, orderly, non-random way.

Question 5

What is artificial selection?

Answer 5

A human selecting the offspring and adding genes to artificially make it better suited to the environment.

Question 6

What is decent with modification?

Answer 6

Decent with modification is only found in offspring.

Question 7

What is common decent?

Answer 7

The theory that we all have a common ancestor.

Question 8

The evidence to support the theory of evolution.

Answer 8

1. The observations on Galapagos islands (plants and animals)
2. Similar anatomy (similar embryos)
3. Homologous structures
4. Fossils (fossil/records)

Question 9

What were the observations on Galapagos islands?

Answer 9

1. Good location to observe evolution
2. Untouched by humans, bio diverse
3. Pinchers with different size beaks
4. Same plant, grew different heights

Question 10

What is similar anatomy?

Answer 10

Embryonic features which disappear as the fetus grows but are found in other species.

Question 11

What is embryo?

Answer 11

The first stage of pregnancy, before the fetus.

Question 12

Two examples of an embryonic feature?

Answer 12

1. Gill slits appear in aquatic vertebrates but also in terrestrial vertebrates (reptiles, birds, mammals)
2. A tail is present in a human embryo, it disappears as the embryo grows.

Question 13

What are homologous structures?

Answer 13

Features that have similar structures but may have different functions (e.g. Bat. whale, cat, horse and human- same structure in forearm but different functions)

Question 14

Describe the horse evolution.

Answer 14

The horse fossils are so similar to present day organisms (horses) that is extremely simple to relate that fossil to the modern animal. Horses have the compete fossil record.

Question 15

What are the steps of natural selection?

Answer 15

• Overproduction
• Variation in the population
• Competition (more suited phenotype survives)
• Selection (advantaged phenotype survives and will reproduce)

Question 16

How does selective pressure influence natural selection?

Answer 16

Some members of the population will not survive and reproduce and thus will not pass on their genes into the next generation.

Question 17

What are the selective agents in natural selection?

Answer 17

Any factor that affects fertility or mortality. Selecting agents include available food sources or local predators.