A type of methodological species concept
- a species is a group of organisms conforming to a common morphological plan, emphasizing the species as an essentially static, non variable assemblige
- not effective meahthod, doesnt take variation into account
Typological
A type of methodological species concept
-Wheeler and Platnick version- the smallest aggregation of (sexual) populations or (asexual) lineages diagnosable by a unique combination of character states.
Phylogenic species concept (PSC)
groups of interbreeding natural populations that are reproductively isolated from other such groups (Mayr)
Biological species concept (BSC)
an enitity composed of organisms that maintains its identity from other such entities through time and over space an that has its own independent evolutionary fate and historical tendencies.
Evolutionary species concept (ESC)
interacting populations
Metapopulations
one large population that gets isolated into two or more-some barrier splits the population
- population adapt to local conditions
- become different enough that they dont interbreed
- probably most common
allopatric speciation
ex/snapping shrimp and Isthmus
breaks off from original, special case of allopatry
- adaptive landscapes
- the colony undergoes a shift between peaks
- can climb back up different hill
- uses genetic drift
peripatric
some kind of selecting gradient splits species
-if your only half good at one thing and half good at the other, this could cause you to be disadvantages in both
Parapatric
species separate together
-no geography boundary
Sympatric
ex/chiclids and apple magot flies
- deter mating
- prevent fertilization from occurring
- may look alike but call could be different
prezygotic isolating mechanisms
ex/lacewings, urchin
- decrease survivability
- hybrids happen but have reduced fitness
- female doesnt like call
postzygotic isolating mechanisms
ex/ epichna niponica, grasshoper
breed at different times
temporal isolation
breed on different hosts
habitat isolation
dont recognize other as same species
behavorial isolation
plants with different pollinators and different morphologies because of it
pollinator isolation
genitaia in insects might not match and male gamets not transferred
mechanical isolation
fertilization fails because of behavior during mating or genialia stimulate properly
copulatory behavior isolation
gametes fail to unite
ex/urchin
gametic isolation
hybrid fitness depends on context
extrinsic
hybrids dont have a niche
ecological inviability
hybrids less successful in obtaining mates
behavorial sterality
hybrid fitness always low
intrinsic
hybrids dont survive
hybrid inviability
structual differences in chromosomes can cause incorect number of genes (aneuoliody) in meiosis
hybrid sterality
