Transcript Welcome to Class

How do we know Evolution occurs?
Agenda for Friday May 27th
1. Quiz
2. Evidence of Evolution Notes
** Rat Island Evolution Due Monday!
All Late work is due next Friday!!
Fossil Record
• Provides a record or species that lived long ago
• Compare past and present species
• Transitional Fossils – fossils that contain features
of several species
– Derived trait – newly evolved traits not in ancestral
species
– Ancestral traits – primitive features in ancestral
species
Homologous Structures
• Similar features that originated in a common
ancestor
• Develop from same embryonic structure
• Have similar structure but different functions
Analogous Structures
• Serve identical functions and look somewhat
alike
• BUT, very different in embryologic development
Moth
Bat
Pterodactyl
Bird
Vestigial Structures
• Features that were once used but no longer
serve a function
• Organism with vestigial feature probably share
common ancestry with an organism that has a
functional version of the same feature
Whale
Snake
Similarities in Embryology
• Early embryos of many different vertebrate
species look similar
• Similarities in early development are a indication
of common ancestry
Similarities in Macromolecules
• Similar species share similar amino acid
sequences
• The more similar the proteins are in different
species the more closely related the species are
List the evidence we have for
evolution.
Agenda for Wednesday June 1st
1. Review Evidence of Evolution
2. Evidence of Evolution Lab – Analyzing Amino
Acid Sequences
3. Phylogenetic Trees
Phylogenetic Tree
What is a Phylogenetic Tree?
• A branching diagram showing evolutionary
relationships among species based on similarities
and differences in physical and/or genetic
characteristics
Uses of Phylogenetic Trees
• Organize knowledge of biological diversity,
• Structure classifications,
• Providing insight into events that occurred
during evolution.
• Trees show descent from a common ancestor
This tree shows that gibbons diverged before other primate
groups.
Chimps and humans diverged last.
Number of differences from
human cytochrome c
Species
Monkey
1
Rabbit
4
Horse
6
Chicken
7
Frog
8
Turtle
8
Tuna
13
Shark
14
If 2 organisms have similar amino acid
sequences, what can we infer about the 2
organisms?
Agenda for Thursday June 2nd
1. Cladograms/phylogenetic trees
2. Mechanisms of Evolution notes