BIO120 Midterm 2 Flashcards
(134 cards)
taxonomic diversification
divergence causing a change in species name
Taxonomy
The scientific study of how living things are classified; like the vocabulary to the grammar of systematics
Carol Linnaeus
Father of Taxonomy; established his classification of living things; famous for animal naming system of binomial nomenclature; came BEFORE Darwin
sympatric
within a region
Allopatric
across regions
taxonomic (morphological) naming of species
naming based mostly on distinct measurable differences
biological naming of species
naming based on inter-fertility
Biological Species Concept (BSC)
Defines species as groups of interbreeding populations that are reproductively isolated from other groups
allopatric speciation
The formation of new species in populations that are geographically isolated from one another.
vitelline envelope receptor (VERL)/Lysin interaction
- an example of a reproductive isolating barrier (prezygotic barrier) in Lecture 9
- VERL (egg of abalone) only takes specific lysin sperm.
- Like a molecular “lock and key”
pre-zygotic barriers
A reproductive barrier that impedes mating between species or hinders fertilization if interspecific mating is attempted@ so NO zygote gets formed (geography@ ecology@ temporal@ behaviour@ mechanical [genital compatibility]@ cellular)
apple maggot flies
have different timing of mating depending on preferred host plant; example of prezygotic barrier because the different mating periods reduces fly gene flow by 94%!!! in sympatry
post zygotic barriers
- caused by?
- favoured by natural selection?
- prevent proper functioning of zygotes once they are formed;
- caused by combinations of genes with low fitness in the hybrid;
- CANNOT be favored by natural selection;
Intrinsic Postzygotic Barriers
hybrid inviability@ hybrid sterility@ or abnormal development of hybrids
Extrinsic Postzygotic Barriers
mismatch of phenotypes in hybrids to environment
sterile
incapable of reproducing
Hinny
cross of a male horse and female donkey; opposed to mules which is vice versa. example of intrinsic postzygotic isolation in lecture 9
Heliconius butterflies
example of extrinsic post-zygotic isolation; CAN form hybrids@ but those hybrids can’t mate and are less viable
ecological speciation
the evolution of reproductive barriers between populations by local adaptation
4 things commonly ID an adaptive radiation:
1) recent common ancestry
2) phenotype-environment correlation
3) trait utility
4) rapid speciation
clade
A group of species that includes an ancestral species and all its descendants.
hybridization
the exchange of genes between species
what causes adaptive radiations?
1) ecological opportunity
2)key innovations
3) high rates of speciation to characterize the clade
ploidy
is the number of complete sets of chromosomes in a cell