Mus musculus

• 85% homology with human DNA

• Genome of appx. 3 million base pairs

Xenoturburelli

• No brain, spine, gut or sex organs

• ~50% homology with humans

Musa acuminata

• 50% Homology With Humans

Drosophila melanogaster

• 44% Homology With Humans

• Shares many similar disorders with humans including insomnia

Saccharomyces cerevisiae

• 26% Homology With Humans

• Share the same genes responsible for breast cancer

Escherichia coli

• 7% Homology With Humans

• Harmful strains have 1300 genes; harmless have only 530 genes

Phylogeny

• Def: The Evolutionary History of A Species

Evidence For Evolution

• Fossil Evidence

• Homologous Structures– Analogous structures show convergence

• Embryological Similarities

• Biochemical Similarities

• DNA Homology

Cytochrome C Homology

cow tuna

Tuna

cow

How Did Modern Humans Evolve?

General Primate Characteristics

• Mammals• Large cerebral volume• Binocular vision• Rotatating forearms & shoulder sockets• Opposable digits

Why have primates diverged over the last 65 million years?

Prosimians

• First group of mammals with primate characteristics

• Adapted for habitat & niche in trees

Tectonic Shifts 65mya to present

New v. Old World Monkeys

• Due to continental drift and competition, primates diverge into two smaller factions– Old World (African)– New World (South

American) – Despite name, old

world monkeys include apes, chimps and orangutans

Miocene Changes & Old World Monkeys

• Cool weather appx 23.7 mya causes drastic reduction in size of rainforest biome

• Increased competition among Old World monkeys

• Those with variations to stand upright are favored for survival on savannah

“Monkeys” v. “Apes”?

• True monkeys diverge from apes 8 million years ago

• Apes diverge into two subgroups– Chimp/Gorilla– Southern Apes

Which Model Is Supported?

• “Lumpers”• The chimps, apes

and hominoids all diverged at the same time

• “Splitters”• Chimps and apes

diverged first• Hominoids diverged

from chimps later

Lab: Proving Primate Phylogeny via DNA Hybridization of the RH1

Using the RH Factor As Evolutionary Evidence

• Among primates, there is variance between the DNA sequences in the introns that are part of the Rh1 blood factor

• By hybridizing DNA from the Rh1 intron with cDNA from a related species, we can determine which species have diverged most recently.

Protocol• 1) On your table, you should have five models

of DNA and cDNA sequences– Human DNA Template of Rh1 Intron

– Human cDNA for Rh1 Intron

– Chimpanzee cDNA for Rh1 Intron

– Gorilla cDNA for Rh1 Intron

– Paranthopus DNA Template for Rh1 Intron

• 2) In each model the following colors represent various nucleotides– Adenine = Black– Cytosine = Red– Guanine = Yellow– Thymine = Blue

Protocol• 3) Make the following comparisons and record

how many nucleotides are incorrectly paired (i.e. A-G, C-T, etc.)

Pairing Sequences # of Differences

Human Template-Chimp cDNA 1 v. 3

Human Template-Gorilla cDNA 1 v. 4

Paranthopus Template-Human cDNA 5 v. 2

Paranthopus Template-Chimp cDNA 5 v. 3

Paranthopus Template-Gorilla cDNA 5 v. 4