Evolution & Natural Selection Flashcards
Evolution Caused by…
Change of allele frequencies of the population
Natural Selection (def)
Organisms born w/ characteristics which help them survive
Geologist; “Earth very old”
George Buffon
Paleontologist; “fossils show waves of extinction”
George Cuvier
Biologist; “species change over time”
Jean Baptiste Lamark
Geologist; “earth changing not static”
Charles Lyell
Earth age pre 19th Century
6000-7000 yrs. old
Darwins Ship
“the Beagle” ; converted warship
x2 Galapagos patterns
- Traits shared within populations/ species
2. Similarity between fossils and living species
Darwin Published;
‘Origin of Species”
Darwin challenged 2 biblical beliefs;
- world is only 6000 yrs. old
2. Species were placed directly by God
x4 Mechanisms of Evolution
- Mutation
- Genetic drift
- Migration
- Natural Selection
Evolution & Natural Selection…
Not the same thing!
Mutations
- Direct change in DNA
- Change in DNA sequence changes Allele
Mutagens
Chemical which induce mutations
Genetic Drift
Change in Allele freq. is NOT related to alleles influence on reproductive success
Migration
Movement of individuals from one population to another
A.K.A. Gene Flow
Natural Selection characteristics/ survival of the fittest
- Trait variation
- Variation must be inheritable
- Differential reproductive success
Fitness
Measure of a relative amount of reproduction of an individual with a specific Phenotype
Molecular Biology
common genetic sequences link all life forms
