Answer key posted on the class webpage Office hours: M 10am-1pm T 11:30am-1pm, 3-4pm Exam Error Worksheet Bonus #1 due now

Evolution does not always occur at the same rate. CB 26.8 Evolution does not always occur at the same rate.

CB 25.18 Tree of Life

The Genetic Code is universal in almost every organism on earth CB 17.5

Spontaneous Generation: Life from non-living material

The Miller-Urey experiment CB 26.2 The Miller-Urey experiment

Inorganic compounds (cyanide) frozen at -780C for 25 years Organic compounds (adenine, guanine, glycine, etc) Prebiotic Synthesis of Adenine and Amino Acids Under Europa-like Conditions by Matthew Levy, Stanley L. Miller, Karen Brinton, Jeffrey L. Bada (2000) Icarus vol 145, Issue 2, pg 609-613

CB 25.18 Tree of Life

How are we related, and where did we come from? CB 34.41

The earth is covered in H. sapiens, but it wasn’t always.

When did these migrations take place?

DNA is passed from generation to generation, and therefore can tell us about relationships between individuals. CB 34.38

Human DNA is divided into 46 chromosomes (23 pairs)

Each of us are a combination of DNA from mom and dad. X 23 in humans X 23 in humans X 23 in humans Each of us are a combination of DNA from mom and dad.

… because Mom provides 100% of mitochondrial DNA Mom provides 50.000275% and Dad provides 49.999825% of DNA to offspring. … because Mom provides 100% of mitochondrial DNA CB 13.5

Mitochondrial DNA comparisons can be used to trace ancestry:

Non-Coding DNA is used for comparisons between individuals

As DNA is passed on mutations take place Fig 1 and 4

Fig 4

By determining the average time between mutations, we can estimate the time of the last common ancestor. Fig 4

The mutation rate in human mtDNA is one nucleotide change per 20,000 years. OR A difference of one nucleotide between two people indicates a common relative 10,000 years ago. Fig 4

When did these migrations take place?

Two hypotheses about the origin of H. sapiens Multiregional hypothesis “Out of Africa” hypothesis

Relationships of different populations using mtDNA ~150,000ya 7 Daughters of Eve, fig. 1

Two hypotheses about the origin of H. sapiens Multiregional hypothesis “Out of Africa” hypothesis

Relationships of different people using mtDNA. 7 Daughters of Eve, fig. 2

Relationships of different people using mtDNA. 7 Daughters of Eve, fig. 2

Relationships of different people using mtDNA. 7 Daughters of Eve, fig. 2

Relationships of different people using mtDNA. From Science v298 12/20/02 pg 2381 93-95% of genetic variation within population. 3-5% of genetic variation occurs between populations. 7 Daughters of Eve, fig. 2

“Man’s Most Dangerous Myth: the Fallacy of Race” by Ashley Montagu

“Man’s Most Dangerous Myth: the Fallacy of Race” by Ashley Montagu first published in 1942

There is no genetic definition of race.