Evolution and Natural Selection - Darwin's Theory of Evolution by Natural Selection (worksheet)

Question 1

Darwin’s theory was based on what 4 observations?

Answer 1

1. Individuals within species differ from eachother - variation.
2. Offspring resemble their parents - inherited characteristics.
3. Far more offspring produced than survive to maturity - die young from diseases, predation, competition.
4. Populations usually fairly constant in size.

Question 2

Overall, what did Darwin conclude?

Answer 2

That individuals better adapted to their environment compete better than others, survive longer and reproduce more, passing on their successful genes to the next generation.

Question 3

Summarise how Darwin explained the giraffe’s long neck?

Answer 3

1. Population of horse-like animals random genetic variation in neck length.
2. Longer necked animals better adapted to reach more leaves, competed better than short-necked relatives. Longer necked animals lived longer, more breeding seasons, more offspring.
3. Shorter necked animals lose competion, poorly nourished and die from predation/disease. Few offspring.
4. Next generation more long-necked alleles in population.

Question 4

What was Darwin the first to accomplish?

Answer 4

The first plausible mechanism for evolution - natural selection providing wealth.

Question 5

What did Darwin used to explain natural selection?

Answer 5

The analogy of selective breeding.

Question 6

What is selective breeding?

Answer 6

When desirable characteristics are chosen by human and those only individual with the best characteristics are used for breeding - species change over a period of time.

Question 7

What is one difference between selective breeding and natural selection?

Answer 7

Humans have a goal in mind nature does not.