Chapter 25 Flashcards
evolution that produces species
macroevolution
biological species concept:
- based on ___
- populations of a species can ___ or are ___
- members of a species are ___ from other species
- this species concept hold up well for animals, not so well for many plants or bacteria
- reproductive isolation
- interbreed, interbreeding
- reproductively isolated
- based on anatomical differences between species
- similar to phylogenetic species concept
- similar to paleontological species concept utilized to identify fossil species
morphological species concept
distinct mating adaptations by species - molecular, form, behavior
-example: peacocks tail
recognition species concept
emphasizes factors that maintain the distinct form and behavior of a species. factors include such things as reproductive barriers
cohesion (pluralistic) species concept
species are identified by where they live and how they behave, not what they look like
ecological species concept
emphasizes the evolutionary history of a species and the species’ unique role in the environment
-similar to the evolutionary lineage concept
evolutionary species concept
2 types of reproductive barriers aka reproductive isolation mechanisms
- prezygotic barriers
- postzygotic barriers
impede reproduction and fertilization of the ova between species
prezygotic barriers
these prevent the development of a viable, fertile offspring
postzygotic barriers
prezygotic barriers (5)
- habitat isolation
- behavioral isolation
- temporal isolation
- mechanical isolation
- gametic isolation
postzygotic barriers (3)
- reduced hybrid viability (inviability)
- reduced hybrid fertility (sterility)
- hybrid breakdown
the origin of species
speciation
two types of speciation
- allopatric speciation
- sympatric speciation
involves geographical isolation
-the geographical barriers required for this can be almost anything, lakes, oceans, rivers, mountain ranges, deserts, etc.
allopatric speciation
in this form of speciation the populations are not geographically divergent but become genetically divergent
sympatric speciation
species arranged in a ring around a geographical barrier - allopatric speciation in process
ring species
allopatric speciation is more likely if:
- the environment is ___ for the isolated populations
- if an isolated population comes from a ___
- if the isolated population is ___
- different
- peripheral area
- small
new plant species can arise through ___
polyploidy
extra sets of chromosomes
polyploidy
polyploidy in an individual
autopolyploidy
formation of a polyploidy offspring from two different species
allopolyploidy
