How Do We Know Living Things Are Related?

Front

What is a clue that all living things are connected?

Back

The similarity in basic structure of body parts like a cat’s paw, a bat’s wing, and a human hand.

Front

What do scientists believe about many animals?

Back

Scientists believe that many animals share a common ancestor from which different animals evolved.

Front

What are the three main types of evidence for common ancestry?

Back

Homology, embryology, and genetics.

Front

What are homologous structures?

Back

Body parts that look similar in different animals because they come from the same ancestor.

Front

Give an example of homologous structures.

Back

The bones in a whale’s flipper, a human arm, and a bird’s wing are arranged in a similar pattern.

Front

What does embryology study?

Back

Embryology is the study of how animals grow before they are born or hatched.

Front

What do scientists notice about embryos of different animals?

Back

Many animals look very similar at early stages of development, such as having tails and tiny gill-like structures.

Front

What does DNA tell us about living things?

Back

The more similar the DNA is between two species, the more closely related they are.

Front

What percentage of DNA do humans and bananas share?

Back

Humans and bananas share about 60% of the same DNA.

Front

What do homologous structures, embryo similarities, and shared DNA suggest?

Back

They suggest that many living things are connected through common ancestry.