Slide Set 10 Flashcards
general principles of natural selection
- individuals vary some inherited
- organisms produce more offspring than needed
- offspring have inherited characteristics to suit environment
three life cycle plans with 1 common thread
- alternation of meiosis
- net effect new characteristics appear
inbreeding in animals leads to ______
problems
domestic crops are dominated by what 4 species?
wheat, maize, rice, potato
can domestic crops survive in the wild?
most would not survive as genetic diversity is very low
smaller islands have a ______ degree of inbreeding
greater
parasite load is ______ with degree of inbreedign
correlated
innate immunity is ____ in more inbred populations
lower
adaptation
a trait that increases the ability of an individual to survive or reproduce compared with individuals without the trait
describe adaptaion in chili pepper plants
- ability to produce spicy chemical
- pack rats eat chilies
- spiciness increases
Acclimation
can refer to the changes in the form or behaviour of an individual during its life as a response to environmental stimuli
speciation
the process in which two or more contemporaneous species evolve from a single ancestor
Adaptive radiation
the evoltuionary divergence of monophyletic taxon into a number of very different forms and lifestyles
both ____ and ____ can lead to reduced fitness
inbreeding and outbreeding
Prezygotic mechanisms in preventing hybridization includes
blockages at different steps that prevent the formation of a zygote in the first
describe prezygotic ecological separation
failure to encounter because mating sites are different
temporal separation
differences in the timing of fertile periods
describe behavioural separation
Darwin’s finches recognize and respond to different songs, by-and-large preventing hybridization
describe prezygotic mechanisms in plants
biochemical barriers to the formation of a pollen tube prevents fertilization
Can two independent populations, which appear to be separate species, hybridize when they meet again?
depends on time, rate of genetic change and degree of speciation
what are the 4 mechanisms of speciation?
- allopatric speciation
- parapatric speciation
- sympatric speciation
- polyploidy
allopatric speciation
- formation of new species that occurs when populations are geographically isolated
- divergence of populations into separate species as a result of geographic isolation from one another
vicariance
splitting
what is an ex of allopatric speciation via vicariance
- isolation of a continental island by rising sea levels