vocabulary Flashcards
evolution
the way an organism changes, changing trends in a population, how species adapts to the environment
mutations
bad (genetic disorders), neutral or good (random changes that give the organism increased reproductive success
artificial selection
direct breeding where individuals that exhibit a certain trait are chosen as parents of the next generation
adaptations
a structure, behavioural or physiological process that helps an organism survive and reproduce
variations
differences between individuals which may be structural behavioural or physiological
natural selection
change in population over time as advantageous, heritable traits are passed onto next generations
homologous features
structure with common evolutionary origin but has different functions in species
analogous features
structure that performs same function, different origins
vestigial features
non-functioning or marginally functioning that is homologous to a fully functioning structure in closely related species
biogeography
observation of geographical patterns of the distribution of species, original species evolved into geographically isolated
anatomical
animals with different structures on the surface but bones tell common ancestor
gene flow
migration, alleles go from one population to another, changes the gene pool
gene drift
alteration of allele frequency, change from chance events, decreased genetic variation
allopatric speciation
evolution of population into 2 different species by geographical barrier
sympatric speciation
population within same geographical areas diverge and become geographically isolated
microevolution
changes in allele frequency and phenotype traits within a population of species (over a short time)
macroevolution
large-scale changes include formation of new species (over a long time)
pre-zygotic mechanisms
prevents mating or fertilization between species
post-zygotic mechanisms
if fertilization is successful, prevention of zygotes from developing into fertile individuals
phylogeny
evolutionary relationships of different groups of species of organisms
derived traits
trait that has evolved relatively recentyly with respect to the species or groups discussed
out group
oldest ancestor that doesn’t share traits with other in the group being studied
synapomorphy
derived trait shared by 2 or more species
