speciation Flashcards
organism of the day:
read oak
quercus rubra
what is species?
Species is group of ________ whose members have the potential to ______ in natural and produce ________ offspring but do not produce viable, fertile offspring with members of _______.
Species is group of populations whose members have the potential to interbreed in natural and produce viable offspring but do not produce viable, fertile offspring with members of other such groups.
Becuase species are defined in terms of reproductive compatibility formation of new species hinges on ________, that include prezygotic and postzygotic
a combination of the barrier may not prevent gene flow
formation of new species hinges on reproductive isolation, that includes prezygotic and postzygotic
postzygotic —
barriers that produce hybrid not viable cause the hybrid to be ____ or _____
barriers that produce hybrid not viable cause the hybrid to decrease the chance of survival of the hybrid or hybrid embryo
prezygotic:
habitat isolation, _______,behavioral isolation, mechanical isolation
habitat isolation, temporal isolation(different mating time), behavioral isolation, mechanical isolation (attemped but pathological difference prevent)
Since chromosomes of the two parent species differ in ______ or ______, meiosis in the hybrids may fail to produce normal gamete
Since chromosomes of the two parent species differ in number or structure, meiosis in the hybrids may fail to produce normal gamete
Allopatric speciation(different descents live in different habitat) : occurs when populations are ________ Reproductive isolation may then arise as a by-product of selection or drift
Allopatric speciation(different descents live in different habitat) : occurs when populations are geographically isolated
Sympatric speciation(different descents live in the same habitat): occurs when populations are in ___________
Sympatric speciation(different descents live in the same habitat): occurs when populations are in same geographic area`
polyploidy is the duplication of _____ of chromosomes resulting from _________ and is common in plants that ______. Organisms with __ numbers of chromosome copies are often not viable because errors result during meiosis
polyploidy is the duplication of complete sets of chromosomes resulting from nondisjunction and is common in plants that self-fertilize. Organisms with odd numbers of chromosome copies are often not viable because errors result during meiosis
______ is an individual that has more than two chromosome sets that are all derived from a single species
autopolyoid is an individual that has more than two chromosome sets that are all derived from a single species
geographic isolation severely______. As a result, other reproductive barriers from the ancestral species may arise as a by-product of genetic changes
geographic isolation severely restricts gene flow. As a result, other reproductive barriers from the ancestral species may arise as a by-product of genetic changes
Sympatric speciation:
a new species originates while remaining in the same ______ as the parent species.
a new species originates while remaining in the same geographic area as the parent species.
odd number chromosomes not stable, can’t pair in meiosis, often sterile:
_______ and watermelon
triploid
odd number chromosomes not stable, can’t pair in meiosis, often sterile:
seedless banana and watermelon
triploid
even number chromosomes are stable, _____, may have hybrid vigor
_____, wheat, salmonids
tetraploid, hexaploid
even number chromosomes are stable, fertile, may have hybrid vigor
cotton, wheat, salmonids
tetraploid, hexaploid
Ecological speciation occurs as a result of _______ divergent natural selection and is maintained because ______ between satellite and core population have lower fitness
Ecological speciation occurs as a result of ecologically-based divergent natural selection and is maintained because hybrids between satellite and core population have lower fitness
