Chapter 6 Exam Evolution

Evolution

Theory that species change over time.

What is a species?

Groups of organisms whose members successfully reproduce among themselves.

What causes evolution to occur?

Factors like mutation, migration, geographic isolation, and climate changes.

Lamarckism

Theory of Acquired Traits, suggesting species evolve by keeping traits their parents developed during their lives.

Theory of Use and Disuse

As needs change, organisms develop new traits in their lifetime to meet those needs.

Charles Darwin

Naturalist who proposed the Theory of Natural Selection.

Natural Selection

Organisms with traits best suited to their environment are more likely to survive and reproduce.

Survival of the Fittest

Goal to possess traits that allow survival long enough to reproduce.

Darwin's Four Observations

1. More offspring than can survive (Competition); 2. Differences among individuals (Variations); 3. Some variations give advantages (Adaptations); 4. Future generations show more members with advantageous variations.

Adaptation

A variation that gives an organism an advantage over other members of the same species.

Mimicry

A harmless species resembling a dangerous one for survival.

Fossils

Remains of life from an earlier time.

Relative Dating

Dating fossils by their position in rock layers; deeper layers are older.

Radioactive Dating

Measuring the decay of radioactive elements to determine the age of fossils.

Homologous Structures

Body structures in different species that are similar in structure but used for different purposes.

Vestigial Structures

Reduced body parts that are no longer useful, indicating relationship with other species.

Primate

Apelike, monkeys, apes, and humans.

Characteristics of Primates

1. Opposable thumbs; 2. Binocular vision; 3. Flexible shoulders; 4. Rotating forelimbs.