Change Over Time

Front

What does the presence of a pelvis and femurs in whales indicate?

Back

Whales are descended from an ancestor that was able to walk.

Front

What are vestigial structures?

Back

Remnants of once-important structures that have slowly lost all or most of their function.

Front

What does the similarity of bones in different organisms suggest?

Back

The organisms shown may have developed from a common ancestor.

Front

What can scientists infer if a fish fossil is found in a desert?

Back

Water once covered the area where this fossil was found.

Front

Why are advantageous traits more likely to be passed onto offspring?

Back

Because they are more likely to survive and reproduce.

Front

What is natural selection?

Back

The process by which organisms better adapted to their environment tend to survive and produce more offspring.

Front

Define evolution.

Back

The change in the heritable characteristics of biological populations over successive generations.

Front

What is a common ancestor?

Back

An ancestral species from which two or more species have evolved.

Front

What are homologous structures?

Back

Structures in different species that are similar due to shared ancestry.

Front

What is the significance of fossils in understanding evolution?

Back

Fossils provide evidence of past life forms and their changes over time.