Darwin and natural selection Flashcards
What does natural selection act on?
Phenotype
Natural selection works on the expression or appearance of an inherited trait, not the genotype.
What is the result of natural selection occurring over many generations?
Evolution
Evolution is the change in populations over time as a result of natural selection.
Who coined the term ‘survival of the fittest’?
Herbert Spencer
He referred to reproductive success as ‘fitness’.
What is an example of evolution mentioned in the text?
Evolution of Large Billed Finches on Galapagos Island
Individuals with a selective advantage are more likely to survive and reproduce.
What does natural selection favor?
Reproductive success
It favors some individuals over others within a population.
What is the difference between adaptation and evolution?
Individuals ADAPT, Populations EVOLVE
A single change does not represent evolution until it causes a population change.
In what year did Darwin complete his theory of natural selection?
1844
What significant event happened in 1858 related to natural selection?
Alfred Wallace sent Darwin a manuscript containing a theory of natural selection identical to Darwin’s.
What was the title of Darwin’s book published in 1859?
On the Origin of Species by Means of Natural Selection
This book provided evidence for evolution and how it occurs.
What did Darwin recognize about the Galapagos environment?
It was a harsh environment with a constant ‘struggle for existence’.
What are adaptations?
Traits that help an organism be more suited to its environment.
What are key points of natural selection?
- Individuals within a species vary in many ways
- Some variability is inheritable
- Members of the same species compete
- Organisms produce more offspring than the environment can support
- Individuals with favorable variations are more likely to survive
As favorable individuals contribute more to succeeding generations, those variations become more common.
Summarize Darwin’s theory in one sentence.
Natural selection preserves favorable variations within a population while eliminating injurious ones.
What was the outcome of the Scopes Monkey Trial?
John Scopes was found guilty and fined $100 for teaching evolution.
What did Darwin identify while in the Galapagos?
13 previously unknown species of finches.
What did Darwin observe about isolated species?
They often resemble species on the nearest continental land mass.
What was Darwin’s role on the HMS Beagle?
Naturalist
He studied geology, plants, and animals during the voyage.
What did Darwin collect during his voyage?
Thousands of specimens and over 4000 pages of notes.
What significant fossil did Darwin find in Patagonia?
Fossils of giant Glytodon resembling smaller modern armadillos.
What discovery did Darwin make regarding marine organisms?
Fossils of marine organisms found high in the Andes mountains.
What did Darwin notice about amphibian species in the Galapagos?
He found NO amphibian species or large land animals.
