Section 7.1 – Adaptation and Variation

In order to be _______________________________________, an organism must _______________ its

environment and ___________________________________________________________.

____________________ in the environment limit the ability of organisms to survive. Those who are

able to survive and be successful, pass on genes that are useful in living in their environment.

Useful genes stay in the population.

Those who are unsuited to their environments often do not survive, and therefore, their genes do not

remain long in the population.

_________________________within a population explains why populations (species) change over time

in a changing environment.

______________________________ is the _______________________between individuals in a species.

Not all variations become adaptations, but all adaptations are the result of variation.

Individuals with _____________________ variations (make them biologically successful) will pass their

DNA on to future generations, and that variation (allele) becomes more _____________________ in the

population.

E.g. peppered moths in England

Adaptations

This is a ________________, ______________________ or _________________________________ that

helps an organism to be biologically successful

e.g.

How do adaptations develop?

They are the result of __________________, ______________________ ____________ that help an

organism survive and reproduce.

They are the result of random, heritable __________________ in the DNA that accumulate over

generations.

When a mutation (variation) is favorable to individuals in a changing environment, the mutation

provides a ______________________________ – it gives an individual an edge over its competitors.

This selective advantage may make an individual more biologically successful.

Complete the following questions:

p. 299 Q 1, 3, 5, 6

p. 304 Q 4, 6, 7, 8, 10, 11, 12