What are the 2 pieces of evidence for evolution we have discussed so

far?

Initiation:

The Evidence for Evolution

Nothing in biology makes sense exceptin the light of evolution.

                        -- Theodosius Dobzhansky

Key QuestionWhat evidence supports the theory of

evolution?

Content Objectives

1.Identify evidence Darwin used to present his case for evolution.

Key Points1.Homologous structures are

one type of evidence for the evolution of living things.

2.Early stages, or embryos, of many animals with back bones are very similar.

Major Vocab•Homologous Structures - Structures

that have different forms but develop from the same embryonic tissue.

•Vestigial Organs - Organ that serves no useful function in an organism.

•Embryo - organism in its early stages of development.

Homologous Body Structure1. Scientists have noticed that animals’ body part structure have striking

similarities.

2. Homologous structures provide strong evidence that all 4-limbed vertebrates

have descended, with modifications, from common ancestors.

What are some examples of 4-limbed vertebrates?

What similarities do you see between these 4 animal parts?

Example 1-Animal Limbs

Even though these structures serve very different functions, their origin is from the same

embryonic tissue.

Example 2 -Vestigial Organs

Humans have several vestigial organs!

The Appendix

The Tailbone

Similarities in Embryology

1.Many embryos look especially similar during early stages of development.

2.The same group of embryonic cells develop in similar patterns.

Example Match the embryo with the proper organism!

DogHuman Mouse Turtle

A DCB

The Leopard Frog

FROG DISSECTION!!!

•You do not have to touch, but you do have to participate.

•No unnecessary cuts.

• If you have a question, ask!

•Respect the animal that we are learning from.

•Have fun!!!

Preview of what you will see...

Write a summary of what you just

learned.

Termination: