3.4.2 Natural Selection

3.4.2 Natural Selection

Poll

Based on the picture, do you think natural selection can affect individuals?

• Yes

• No

Darwin's Postulates

So how do we get new species?

Multiple Choice

Which is the best description of how natural selection changes a species over time?

• Survival of the organisms that occupy the largest area in an environment.

• Survival of the strongest organisms in an environment.

• Survival of the organisms genetically best adapted to the environment.

• Elimination of the smallest organisms by the largest organisms.

Multiple Choice

Why does evolution by means of natural selection act at the population level and not the individual level?

• Individuals cannot change inheritable traits.

• Environmental selective pressures only affect groups of individuals and not the individuals themselves.

• There are usually no significant differences between the individuals of a population.

• Mutations occur so rarely that they are detectable only at the population level.

Multiple Choice

Which correctly identifies how natural selection causes a change in species over time?

• People choose mating pairs based on desirable characteristics.

• The environment favors those individuals with the best phenotypes for survival.

• If an anatomical feature is not used for several generations, offspring will cease to inherit that trait.

• There is a trend toward homozygous dominant genotypes becoming the most common in the population.