Macro/Microevolutionary change

Question 1

What is microevolution?

Answer 1

Changes within a species, which can occur in a short period of time. Produces variants of a population, not new species. (eg. breeds of dogs)

Question 2

What is macroevolution?

Answer 2

Takes place over millions of years, results in new species, or even new families and orders arising.

Question 3

How do changes in environments cause evolution?

Answer 3

As environmental conditions change, resources may become limited and organisms will compete. These selection pressures select for organisms with favourable traits, who will survive in the new environment.

Question 4

How does mutation assist evolution?

Answer 4

Mutations are changes in genetic material that give rise to heritable characteristics. These characteristics create diversity in the population. Selection pressures will select for members of the population with favourable characteristics, and these traits will become more frequent in the population.

Question 5

What are the four types of selection pressures?

Answer 5

Environmental change
Competition
Predation
Disease

Question 6

Describe how changes in physical conditions affected the evolution of the peppered moth

Answer 6

Prior to industrial revolution - pale peppered moth was common - blend in with lichen covered trees
Industrial revolution produced soot - covered trees. Now the minority of black moths blended in and survived. They became the most frequent within the population.

Question 7

Describe how changes in the chemical environment affected mosquito populations.

Answer 7

Poison DDT was effective in killing mosquitos. Some members of populations had a resistance to the poison, survived and passed on the resistance. Now populations of mosquitos are increasingly resistant.