Chapter 2 Flashcards
phenotype
the observable characteristics of an organism
genotype
the genetic makeup of an individual
allele
a gene variant; one of two or more alternative forms of a gene
genetic recombination
a recombination of genes during cell division in sexually reproducing organisms that involves sections of one chromosome “crossing over” and swapping positions with sections of the homologous chromosome
phylogenetic tree
the depiction of phylogeny by using branching, treelike diagrams. phylogeny is evolutionary history via common descent
convergent evolution
the process whereby different populations or species converge on the same phenotypic characteristics as a result of similar natural selection pressures.
heritability
the proportion of variance in a trait that is due to genetic variance
fitness
lifetime reproductive success–usually measured in relative terms
adaptations
a trait that results in the highest fitness among a specified set of behaviors in a particular environment. adaptations are typically the result of the process of natural selection.
mutation
any change in a genetic structure
homology
traits that are shared between two or more species as a result of common descent.
homoplasy
a trait that is present in two or more species but that is not due to common descent but rather results from natural selection acting independently on each species
analogies
traits that are similar as a result of similar selection pressures rather than common descent
migration
the movement of organisms over long distances (often in a seasonal manner)
Dr. Alan Grafen interview
Natural selection is not circular. The science community doesn’t want to say that natural selection has shaped human behavior because science overlaps with other fields and you would have to have biolgists also skilled with the social scientists to be able to completely understand. The only known process capable of producing complex adaptations is natural selection.
