Transcript 15.1 darwin ppt

Evolution
The Puzzle of Life’s Diversity
15-1
Charles Darwin
• Born- England 1809
• At age 22, went on Voyage of the Beagle to
observe evidence for evolution
• Most evidence from GALAPOGOS ISLANDS
• Looked at finches, tortoises, iguanas, armadillos,
and fish
• Came up with “Theory of Natural Selection”
• Wrote the book, “On the Origin of Species”
Voyage of the Beagle
Darwin’s Observations
• Living animals, some captured but most
drawn and numbered in his journal
• Also collected many fossils
• EX: Tortoises on three different islands
• 1. Hood Island: long neck and curved/open
shell
• 2. Isabela Island: short neck and dome shell
• 3. Pinta Island: intermediate neck and shell
• WHY? (see pg 371)
The Journey Home
• Darwin had time to think and analyze the
species he noted and collected
• Why did so many resemble others, but
were not identical?
• Plants and animals alike had minor
variations, could it be because of isolation
or environment, or BOTH???