lecture 6 Flashcards
what does speciation means?
biological, morphospecies, and phylogenetic
how does speciation affect biodiversity
increases it
what is the main criteria for identifying species?
reproductive isolation
what is the difference between prezygotic and postzygotic isolation?
pre zygotic- isolation before mating
post zygotic- not able to produce offspring that can survive
biological species
reproductive success
morphospecies
new and different species
phylogenetic species
identifies or separates species based on their evolutionary history
allopatry-
populations geographically separated
How does allopatric speciation differ in Dispersal
versus Vicariance?
the movement of organisms from one location to a new location
How does this differ from sympatric speciation?
separation despite living in same area
external events
disruptive selection
internal events
chromosomal mutations
Autopolyploidy
created when mutation leads to double chromosomes all from same species
polyploidy
have more than one set of chromosomes
Allopolyploidy
two different species mate and an error in mitosis occurs creating a viable, non sterile offspring with twice the usual chromosomes