Biology 1B (Evolution)John Huelsenbeck

Alexander Fleming(1881–1955)

Pseudomonas aeruginosa(The greenish tint to the

bacterial lawn is caused by the bacteria itself)

Staphylococcus aureus(Bacterial lawn is yellow tinged. Note zone of inhibition by Oxacillin disk.)

Well-defined margin of inhibition around disk.

The small zone of inhibition around this Ceftriaxone disk is interpreted as resistance.

71 (1880)

65 (1874)45 (1854)31 (1840)7 (1816)

Westminster Abbey

Marine Iguana

Land Iguana

Galapagos Tortoise

A Darwin Finch

Chihuahua Great Dane Sheep Dog

WolfGolden Retriever

Biogeography: The study of the geographicdistribution of organisms.

A. Distribution of species (or kinds) on continents.

NewWorld

OldWorld

Observation: Greater similarity within acontinent than between continents, evenin comparison of similar habitats.

Example: New world and old world monkeys

Platyrrhines (New World Monkeys)

• South America• Flat nosed, with nostrils having a wide septum.• 3 premolars

Catarrhines (Old World Monkeys)

• Europe, Africa, Asia• Hook-nosed, with nostrils closer together and pointing down.• 2 premolars

Cotton Top Tamarin Snow Monkey

B. Island Biogeography, Darwin’s four observations:

1. Oceanic islands have a low diversity of kinds (29 bird species on the Galapagos vs. >100 species on the Berkeley campus)2. There is a bias in the presence of certain kinds (e.g., Darwin’s Finches; 14 of the 21 endemic bird species on Galapagos are finches)3. The most similar kind to oceanic forms are found on the nearest continent.4. There is a bias in the types of species found on oceanic islands found: plants not found: amphibians insects fresh water fish birds mammals reptiles (some) reptiles (most)

(a) (b)

T3 -> T2

X1Hbox mutant