Biological Evidence of Evolution

Vocabulary

Comparative Anatomy

Homologous Structure

Analogous Structure

Vestigial Structure

Embryology

The science of the development of embryos from fertilization to birth.

Body parts that perform a similar function but differ in structure.

The study of similarities and differences among structures of living species.

Body parts of organisms that are similar in structure and position but different in function.

Body part that has lost its original function trough evolution.

Evidence for Evolution

Living species that are closely related share a close common ancestor.

The degree of relation between species depends on how closely in time they diverged.

Comparative Anatomy

In many species common ancestry is not difficult to see.

Homologous structures suggest that species are related.

The more similar structures are, the more likely that the species had evolved from a recent common ancestor.

Analogous structures suggest that species are not closely related.

Vestigial Structure

An organism that have a vestigial structure suggests that the species is related to an ancestor that used this structure.

Developmental Biology

Embryos of different species often resemble each other at different stages of their development.

Pharyngeal pouches is a trait that develops in different stages in all vertebrate organisms.

Molecular Biology

Molecular biology is the study of gene structure and function.

All organisms have genes and all genes are made of DNA, this supports the idea that all organisms are related.

Scientists study organisms relationships by looking at genes and proteins.

In a molecular clock we can see in what time period species diverged from common ancestors.

The Study of Evolution Today

Scientists have different ideas about the rate in which natural selection produces new species.

Evolution have produced Earth's wide diversity of organisms.

Essential Questions

What evidence from living species supports the theory that species descend from other species over time?

The comparative anatomy, vestigial structures, development biology and molecular biology.

How are Earth's organisms related?

They came from the same ancestor and changed trough evolution.