Inquiry 10.21 and 22

No Warm-Up Today!Take out your quiz review assignment for check-off.

Learning Targets

Quiz Review Self-Check

•Check your work with my answer key•Make changes•Ask questions

Evidence for Evolution

Body Structures, Embryos, DNA/RNA Comparisons

Last Time….

•Evidence for Evolution▫Body structures (homologous, vestigial)▫Fossil record▫Relative and radiometric dating▫Comparative embryology▫DNA comparisons

DNA/RNA Comparisons•Genetic similarities between organisms

help scientists determine correct evolutionary trees▫How closely related organisms are▫Who evolved from who, even when physical

similarities aren’t obvious

Am. Vulture

Afr. Vulture

Stork

Types of Evidence from DNA/RNA

•Highly related organisms share a high percentage of DNA in common▫Humans and chimps share

96% of DNA in common▫About 40 million differences

in 3 billion letters▫Only 2,000 of these

differences code for something

(Emory University, 2005)

Types of Evidence from DNA/RNA

•Seemingly unrelated organisms share genes that code for the same proteins▫Humans and yeast both have the gene that

produces the protein myosin▫Myosin is used in human muscle tissue▫Myosin in yeast helps organelles move

“Molecular Clocks”

•The number of mutations found in DNA can help us estimate the length of time between the evolution of two organisms▫Mutations accumulate at a constant rate▫The more differences between two

organisms, the longer apart they evolved from each other

Human/Chimp Chromosome Activity•Read Background and Answer a, b, c (p.

1)•Do Chromosome Analysis #1-9 (p. 1, 2)•Comparison of Human/Chimp

Chromosomes: Do 1, 2 and Answer 3 a-g•3 a-g should be done on the back!

Next Time…

•HOW does evolution happen?•HW: Finish human/chimp chromosome

activity