Text Chapter 10: Speciation Flashcards
Speciation Depends on
isolation (lack of gene flow), genetic divergence
Adaptive Radiation
one species gives rise to many new species in a short period of time
Extinction
death of all members of a species
Microevolution
change within a population or species
Macroevolution
change to a new population or species
Coevolution
species adjust together to maintain relationship
Convergent Evolution
similar phenotypes arise in unrelated species as a result of environmental similarities
Divergent Evolution
different phenotypes arise as related species encounter environmental similarities
Allopatric Speciation
occurs a result of geographical isolation, one group separates from the population, separate evolutionary pressures cause different genetic changes in both groups, most common mechanism
Sympatric Speciation
occurs in the same location, due to ecological isolation or polyploidy
Speciation by Polyploidy
occurs for plants that have a sudden change in numbers of chromosome sets (chromosomes duplicate but do not separate, continued breeding with the offspring of a plant whose chromosomes duplicated but did not separate)
Premating Isolating Mechanism
prevent mating between individuals of different species
Postmating Isolating Mechanism
interferes with development, viability, or fertility, or offspring from matings between species
Behavioral Isolation (Premating Isolating Mechanism)
species-specific signals and elaborate behaviors to attract mates
Ecological Isolation (Premating Isolating Mechanism)
difference in way of life
Ecological Isolation (Premating Isolating Mechanism)
difference in way of life
Geographical Isolation (Premating Isolating Mechanism)
the separation of two populations of the same species or breeding group by a physical barrier
Mechanical Isolation (Premating Isolating Mechanism)
differences in structure of sexual organs
Temporal Isolation (Premating Isolating Mechanism)
difference in timing
Gametic Incompatibility (Postmating Isolating Mechanism)
the sperm of one species will not fertilize the egg of another species
Hybrid Invariability (Postmating Isolating Mechanism)
hybrids between two species do not survive
Hybrid Infertility (Postmating Isolating Mechanism)
hybrid is sterile
Factors that can Lead to Adaptive Radiation
mass extinction, colonization events, evolutionary innovations
Factors that Lead to Extinction
localized distribution of a species, overspecialization, competition, habitat change and destruction
