Evolution and Natural Selection (copy)

What was the aim of sections 16.1 and 16.2 regarding Charles Darwin?

To provide a historical context and the evidence he collected to support the existence of evolution.

What theory did Darwin present confidently by section 16.3?

His theory of evolution.

What is the definition of evolution?

Change over a long period.

What is natural selection?

The process by which evolution occurs.

What is the first condition for natural selection as described by Darwin?

Struggle for existence.

Who influenced Darwin's concept of the struggle for existence?

Malthus.

What does variation mean in the context of natural selection?

Necessary differences that allow individuals to compete for survival.

What is adaptation?

Any heritable characteristic that increases an organism's ability to survive.

What is meant by 'survival of the fittest'?

The concept that organisms best suited to their environment are more likely to survive and reproduce.

What are the three conditions under which natural selection occurs?

1. More individuals are born than can survive (struggle). 2. Natural heritable variation within the population. 3. High fitness leads to survival.

What is common descent as proposed by Darwin?

The idea that all living species are descended from ancient common ancestors.

What is artificial selection?

The process whereby humans select desirable traits for breeding in organisms.

Give an example of artificial selection.

Selective breeding of dogs for specific traits.

What analogy does Darwin use to depict the relationship of species?

The tree of life, illustrating common ancestors branching into diverse species.

Why is competition essential in natural selection?

It determines which individuals survive to reproduce based on available resources.