Isolation Flashcards
Species
Group of organism that can breed in nature and produce fertile offspring
Reproductive barriers
Keep species separate so they can’t mate
Zygote
A fertilized egg
Prezygotic barrier
Prevents mating or fertilization
Postzygotic barrier
Prevents growing, fertile offspring
habitat isolation
Prezygotic barrier: populations live in different habitats so don’t meet
Behavioral isolation
Prezygotic barrier: mating or courtship behavior is different, different sexual attractions
Temporal isolation
Prezygotic barrier: breeding seasons or time of day different
Mechanical isolation
Prezygotic barrier: different body parts preventing mating
Gametic isolation
Prezygotic barrier: gametes don’t join, sperm is not attracted
Hybrid
Offspring from 2 different species
Hybrid zone
Geographic area where interbreeding occurs and hybrids are created
Reduced hybrid viability
Postzygotic barrier: zygote fails to mature
Reduced Hybrid fertility
Postzygotic barrier: hybrids survive but can’t reproduce ex:mule
Hybrid breakdown
Postzygotic barrier: offsprings are fertile but don’t grow as well as pure breeds
Microevolutiom
Small changes within a population ex: color change
Macroevolution
Big changes ex: new species or species wiped out
Speciation
Formation of a new species. Occurs when 2 populations no longer mate with each other
Allopathic speciation
Geographic separation leads to 2 physically separate gene pools
Sympatric speciation
No geographic separation, but have different preferences in where they hang out or who they want to mate with
Gradualism
Speciation that occurs slowly tiny change after tiny change
Punctuated equilibrium
Long periods with no real changes and then a sudden big change
Adaptive radiation
One species quickly
Evolved into many species due to abundant recources
Antibiotic resistance
Some bacteria naturally have mutations to survive an antibiotic. All non resistant bacteria die
Only resistant bacteria survive and reproduce
