natural selection

Question 1

What are the reasons for natural selection?

Answer 1

• Resources are limited and organisms compete for food, shelter and mates
• Organisms are capable of producing more offspring than the number that survive to be mature individuals
• This causes a struggle for existence - overproduction of offspring but limited resources to help them, which leads to competition for resources

Question 2

Natural selection is…

Answer 2

Natural selection is a process in which organisms with certain inherited characteristics are more likely to survive and reproduce than individuals with other characteristics.

Question 3

Evolution is…

Answer 3

Evolution is the development of new types of living organisms from pre-existing types by the accumulation of genetic differences over long periods of time.

Question 4

Natural selection leads to _____ _____, a population’s increase in the frequency of traits suited to the environment.

Answer 4

Natural selection leads to evolutionary adaptation, a population’s increase in the frequency of traits suited to the environment.

Question 5

How do populations evolve? What do these lead to?

Answer 5

1. Individual variation
2. Overproduction and competition

Which lead to unequal reproductive success

Question 6

How do favourable traits accumulate in a population over time?

Answer 6

Individuals whose inherited traits give them a higher probability of surviving and reproducing in a given environment tend to leave more offspring than other individuals. This unequal production of offspring will lead to the accumulation of favourable traits in the population over time.

Question 7

What must the traits be for them to be passed down?

Answer 7

Traits must be present and heritable. Natural selection can amplify or diminish only heritable traits. These acquired characteristics that enable an organism to survive better in the environment must be coded in the genes and passed on to the offspring.

Question 8

What are factors that drive natural selection?

Answer 8

1. Environmental factors
2. Competition
3. Habitat loss
4. Destruction by humans
5. Predation

Question 9

Artificial selection is caused by ___, a deliberate and planned process of ____ ____.

Answer 9

Artificial selection is caused by humans, a deliberate and planned process of selective breeding.

Question 10

What is artificial selection? What are some examples of artificial selection?

Answer 10

Artificial selection involves identifying the largest, best or most useful of the progeny for the intended purpose and using them as the next generation of parents.
Examples: selective breeding of pigeons, domestication of wild animals, improvement of crops such as wheat, rice and maize