Lecture 11 Flashcards
biological species concept def of species
reproductively isolated community in which all individuals potentially r actually interbreed amongst themselves, but are genetically isolated from other groups
2 advantage of biological species concept
reproductive isolation
self define the boundary of their of their species
4 disadvantage of biological species concept
exception, hybrid
too much time to test
asexual reproduction
cannot be used to dead species
1 advantave of morphospecies concept
applied easily
3 disadvantage of morphospecies concept
arbitrary decision
parallel evolution
not give mechanism information
def of phylogenetic species
monophyleti group composed of the smallest diagnosable cluster of individual organisms within which there is parental pattern of ancestry and descend
1 advantage of phylogenetic species
focus operationally defining species
4 disadvantage of phylogenetic species
depend on genetic material used
cannot be used to dead species
expensive
not give mechanism information
2 types of species formation
allopatric
sympatric
allopatric 3 steps
geographical isolation, local adaptation, reproductive isolation
2 types reproductive isolation mechanism
pre-zygotic, post-zygotic
6 types pre-zygotic
geographic isolation
ecological isolation
behavioral isolation
temporal isolation
mechanical isolation
prevention of gamete fusion
3 types post-zygotic
hybrid embryo do not develop properly
hybrid adult do not survive in nature
hybrid adult are sterile or have reduced fertility
2 eg. of living fossils
brachiopod(Silurian志留纪)
horseshoe crab(Ordovician奥陶纪)
def of living fossils
morphologically unchanged since very long ago