Evolution Day-4 Flashcards
Rate of speciation: What is gradualism or gradual speciation?
Gradual speciation is when species diverge at a slow, steady pace as traits change incrementally
What are prezygotic barriers?
Pre-zygotic barrier is a mechanism that blocks reproduction from taking place. This includes barriers that prevent fertilization when species attempt reproduction.
What is behavioral isolation?
Behavioral isolation is a prezygotic barrier when two populations of the same species develop some difference in behavior, typically in mating rituals. They do not recognize mating cues.
What are the types of pre-zygotic barriers?
Habitat Isolation
Temporal Isolation
Behavioral Isolation
Gametic Barrier
Mechanical Isolation
What is a post-zygotic barrier?
A post-sygotic barrier occurs after zygote formation. This includes organisms that don’t survive the embryonic stage and those that are born sterile.
What is a mechanical isolation?
Prezygotic; It is when the species are physically unable to reproduce due to reproductive organ incompatibility, their parts don’t fit!
What is gametic isolation?
Gametic isolation is a prezygotic barrier when two species might produce egg and sperm cells that can’t combine in fertilization, even if they meet up through mating.
What are the types of post-zygotic barriers?
Hybrid Inviability
Hybrid Sterility
What is Hybrid Inviability?
Post-zygotic; Hybrid inviability is the inability to produce a live birth.
What is hybrid sterility?
Post-zygotic; Hybrid sterility is when a live birth is produced, but it is sterile.
What are hybrid zones?
Hybrid zones are regions in which members of different species meet and mate, producing at least some hybrid offspring.
What is habitat islation?
It is a prezygotic barrier; the species remain isolated because they breed in different habitats.
What is temporal isolation?
Temporal Isolation is when two different population breed at different times of the year or day and does not allow them to interbreed.
