Exam 1 Flashcards
taxonomy
the science of classification
taxon
group of organisms in a taxonomy
Natural selection, these three things must be true:
- traits vary within a population
- traits are heritable
- individuals with traits that allow them to survive and reproduce pass those traits on to the next generation
evolution (Darwins defintion)
change in the heritable characteristics of biological populations over successive generations
blending inheritance
after traits have been “blended”, all variation disappears (ex: mixing pink paint with pink paint only makes more pink paint)
genotype
genetic signal
phenotype
the physical expression of a genotype
evolution (modern day definition)
change in allele frequencies (genetic structure) of biological populations over successive generations
four forces of evolution
-mutation
-gene flow
-genetic drift
-natural selection
mutation
appearance of new alleles
gene flow
introduction of new alleles or change in allele frequencies from individuals outside population
genetic drift
-random changes in allele frequencies, usually at small population sizes
-two common types: bottleneck effect, founder effect
natural selection
differential reproductive success of phenotypes, which causes a change in allele frequencies
biological species concept
reproductively isolated breeding populations
morphological species concept
phenotypically distinct populations
ecological species concept
populations occupying distinct ecological niches