42L Top Using your notebook for evidence (notes, reflections), construct a claim and develop a model answering “Why does a human arm and a lizards arm share the same structures?”

add final model to your notebook

What is an evolutionary tree? Tetrapod lineage (animals with four legs) In an evolutionary tree, traits are passed from ancestor to descendant 3

add final model to your notebook In your notebook, create a model (has drawings, labels, explanation), explaining why or how homologous structures exist. 4

42L What is an embryo? Embryo: An organism’s early pre-birth stage of development.

card sort You will be given a set of cards. In the set, there will be 3 stages of embryonic development and 8 species. Look for patterns and organize the embryos into their 8 different species.

What are you looking at?

What organisms do you think these are?

How about now?

And now...

And now... Pig Dog Cat Human

What patterns do you notice?

Fully Developed Observations: 42L Embryo Summary Similarities Differences Embryo Observations: Fully Developed Observations:

Embryo observations A B C D

Fully Developed Organism A B C D

Reflection (42R bottom half of page): 1. Did you have more similarities or differences in your embryo observations chart? Use evidence from your observation chart to explain your answer. 2. Did you have more similarities or differences in your fully developed organisms observations chart? Use evidence from your observation chart to explain your answer. 3. How do you think comparative embryology shows support for evolution?

Read comparative embryology for the vertebrate body

Pg 46L “VESTIGIAL STRUCTURES” Copy the following notes on the TOP OF THE 2ND PAGE A Vestigial structure is a part of an animal’s anatomy that has no function. It is believed that it must have served a purpose in the past. In other words, it’s a leftover body part that can be used as evidence for evolution

46L “EXAMPLES OF VESTIGIAL STRUCTURES” (BOTTOM OF SECOND PAGE) Research 10 (2 human and 8 other animals) different examples of vestigial structures and complete the following chart: TYPE OF ANIMAL NAME OF VESTIGIAL STRUCTURE WHAT WAS ITS EVOLUTIONARY PURPOSE

Vestigial Structures Summary 46L/R Write a paragraph summary explaining how vestigial structures relate to evolution.