You’re a big, fine theory, but you need to back that thang up

Write in complete sentences!Don’t talk during the Catalyst!

What is a common ancestor? What is a homologous structure?

Which two parts of all animal embryos are homologous?

What does this tell us about animal evolution?

Objectives

By the end of today, all SWBAT…

Analyze DNA evidence of evolution

Analyze fossil evidence of evolution

Agenda Catalyst Review Homework review DNA evidence for evolution HUMAN evolution (OMG!!!) Fossil evidence for evolution TRANSITIONAL FORM STATIONS! AWESOME!

Exit Question

Evidence: an object or connection that tends to prove or disprove something.

In science, all theories must be supported with evidence.

DNA Key Point #1:

DNA supports evolution because the more DNA two organisms have in common, the more closely related they are.

All organisms use the same four bases (A, T, G, C) because all organisms evolved from the same original organism!

Original species

New species shares 98% of DNA with original species

New species #2 shares 96% of DNA

with original species

Original species

CRAZY!Humans share:30% of their DNA sequence with Daffodils

65% of their DNA sequence with Frogs

90% of their DNA sequence with Lemurs

99% of their DNA sequence with Chimpanzees

99.9% of their DNA sequence with other Humans

Fossils! Fossils are the remains or imprints of an organism that lived long ago. Preserved tissue, shell or skeleton turned into stone, imprints left in the Earth.

Comparative Anatomy

Scientists can compare the anatomy of different organisms to figure out how closely they are related. Anatomy = body structure

Fossils

Key Point #2: Fossils support evolution in 2 different ways.General TrendsTransitional Fossils

On the right side of your notes, you should have how all of these provide evidence.

General Trends The further you dig, the further back in time you are traveling.

IMPORTANT: As you dig further, fossils tend to be of more primitive and simple creatures!

PRACTICE! Which one of these fossils would be older?

Which fossil is more complex?

If B is an ancient ancestor of A, what do you think fossil C would look like?

A

B

C

A transitional fossil is the fossil of an organism that has traits in between its ancient ancestors and species that came after it.

Transitional Fossils

Human Evolution Homo habilis H. ergaster H. erectus H. heidelbergensis

H. sapiens and H. neanderthalensis

Side-by-Side

Transitional Fossil StationsYou have 5 minutes at each station.

Take a piece of paper and answer each question in complete sentences.

LEARN LEARN LEARN!

Key Point Wrap-Up

Key Point #1: DNA supports evolution because the more DNA two organisms have in common, the more closely related they are.

Key Point #2: Fossils support evolution in 2 different ways. General Trends Transitional Fossils

Exit QuestionsHow do transitional fossils provide evidence for evolution?

Species A has 50% of its DNA in common with Species B, and 95% of its DNA in common with Species C. Which species is A more closely related to?

How do you know? Write in complete sentences!Don’t talk during the Exit Question!