Summary

In this lesson you explored the following essential questions:

• How do mutations create species variability?
• Why is sexual reproduction important to the process of evolution?

Soccer takes balance, timing, speed, and agility. Some of these characteristics are passed on from one generation to the next, and some are not. Some people will be good soccer players, some people will get better with practice, and other people will just never be fast enough to keep up with the others.

In this lesson, you have learned that variations are created by mutations and sexual reproduction.

Variations that allow organisms to survive in their environment are called adaptations.

These adaptations will then be passed on to the next generation. Over time, these variations will change characteristics in a population and lead to the evolution of populations.

Lesson Glossary

adaptation: a beneficial variation that helps an organism survive

mutagen: something that causes an increased rate of mutation

mutation: a change in the genetic material of an organism (DNA)

natural selection: the process that results when the characteristics of a population of organisms change because individuals with certain inherited traits survive specific local environmental conditions and, through reproduction, pass on their traits to their offspring

selective advantage: an organism's variations increase its chances of surviving

selective disadvantage: an organism's variations reduce its chances of surviving

selective pressure: environmental conditions that select for certain characteristics of individuals and select against other characteristics

sexual selection: a type of natural selection where characteristics are selected based on mate preferences

variation: visible or invisible differences between individuals