Evidence for Evolution

Houseflies have very tiny hind wings that are too small to lift them off the ground. Scientists have observed fossils of an ancient insect they believe is related to houseflies. However, these insects had second pair of wings that were much bigger. How does this show support for the theory of evolution?

A. Houseflies have a vestigial structure.

Which supports the idea that birds and butterflies both have wings but they do not have a common ancestor with wings?

A. The wings are analogous structures that evolved differently and do not have a similar internal structure.

The diagram shows the structures of horse and cat forelimbs. What does the diagram suggest about the evolutionary relationship between these two mammals?

A. They have homologous structures, indicating a common ancestor.

Homologous structures

A. always have the same function. B. are found in organisms of the same species. C. always have a different function. X D. are found in organisms of different species.

Monkeys and bats have similar bone structure in their forelimbs. However, monkeys have longer forelimbs to use for climbing and swinging in trees. Bats have shorter forelimbs to use for flight. Which term best describes how monkey and bat forelimbs are related to each other?

A. homologous

Jonas drew a diagram to compare two kinds of evidence that support the theory of evolution.

C. evidence of adaptations to similar environments

Which traits do human embryos have that link them to a common ancestor with fish and reptiles?

C. tail and gill slits

Embryos of different species look very similar, which shows that the organisms share a BLANK ancestor.

Common

The chart shows information about three different embryos early in their development. Which is best supported by the information in the chart?

D. Species X and Y are related to humans.

A student is writing a paper to explain how scientists interpret this image. What is the student most likely explaining?

D. embryology

Which trait is found in early embryos of both birds and humans, but then disappears from each during development?

D. gill slits

BLANK structures are fully functional, show evidence of a common ancestor, and may or may not have the same function in different species.

Homologous

Bats and moths both have wings, but not a common ancestor.

analogous structure:

Which traits do human embryos have that link them to a common ancestor with fish and reptiles? Check all that apply.

hair X tail scales yolk sac X gill slits

Bats have the same arm bone structure as cats.

homologous structure

Frogs, humans, and whales have a backbone.

homologous structure

Pelvic bones in whales are an example of BLANK structures.

vestigial

Homologous Structures

-A homologous structure is a similar body part found in two different species that provides evidence of a common ancestor -Homologous structures may have a different function

Vestigial Structure

-A vestigial structure is a structure that has evolved to no longer be used by an organism -Vestigial structures were once fully functional in an ancestor

Analogous Structures

-An analogous structure is a structure found in two different species that has the same function but evolved differently -Analogous structures show how organisms adapted to similar environments

Comparative Anatomy

-Comparative anatomy is the branch of science that looks at the structures of different organisms and compares them. -Organisms that are closely related to each other have many structured in common

Embryology

-Embryology is the study of the development of an embryo -Embryos of different organisms look very similar, which shows that the organisms share a common ancestor -Certain traits appear in early embryos but may disappear before the organism is fully developed *Gills *Tails

The diagram shows a chicken embryo and a human embryo. Which is best supported by the diagram?

B. Because their embryos have structures similar to gills, chickens and humans likely share a common ancestor with fish.

Which is an example of using comparative anatomy to study evolutionary relationships?

B. studying the digestive system structure in two organisms

Snakes have remnants of back legs

Vestigial Structure