GSC 111 Lecture Notes - Lecture 3: Central America, Darwinism, James Hutton
13 Jan 2017
School
Department
Course
Professor
Darwinian Evolution and the Fossil Record
• Adaptations- characteristics favored by natural selection that allow organisms to function
best in their environment
• Evolution- process by which particular forms of life give rise to other forms
• Natural theology
o Linnaeus was a natural theologian
▪ Philosophy dedicated to discovering the creator’s plan by studying nature
▪ Adaptations were evidence that the creator had designed each and every
species for a particular purpose
▪ Species are individually designed and permanent
▪ Most of the thinking was that Earth was young
• Geological gradualism cleared the path for evolutionary biologists
o James Hutton
▪ 1795- proposed theory of gradualism and rejects catastrophism
• Profound change is the product of slow continuous processes
o Erosion
• Slow processes over long periods of time
▪ got close to describing natural selection but did not describe a process
o Charles Lyell publishes theory of uniformitarianism
▪ Geological processes have not changed throughout Earth’s history
▪ The present is the key to the past
• J.B. Lamarck’s theory of evolution
o Adaptations come from our parents
• Darwin’s evolution by natural selection
o About Darwin
▪ Born in England
▪ In 1825- went to medical school at 16
▪ 1831- B.A. from Cambridge; became naturalist on HMS Beagle
• Went to South America
o Saw animals that were only in the Americas
o Marine organisms on either side of the Central American
Isthmus are drastically different
o Went to Galapagos
▪ Each island has unique species of land tortoises
▪ Studied finches in great detail
• Had unique adaptation
• All were related to mainland finch
• Origin of Species
o Darwin makes four observations to come up with his 3 conclusions
▪ Observation 1: All species have such great potential fertility that their
population size would increase exponentially if all individuals that are
born reproduced successfully
▪ Observation 2: Populations tend to remain stable in size, except for
seasonal fluctuations
find more resources at oneclass.com
find more resources at oneclass.com
