midterm 2 Flashcards
What is the 1st about Darwin’s theory
his theory was the first to be held up by rigorous scientific questioning.
Species are ?
Species are biological units, identified by morphology
Under Biological Species Concept (BSC), a “species” ?
Under Biological Species Concept (BSC), a “species” is a group of organisms that can reproduce with one another but is reproductively isolated from others
According to BSC, species do not ?
According to BSC, species do not breed with each other because they have evolved features that prevent gene exchange
“Isolating mechanisms”
These can be morphological, behavioral, physiological, genetic, or biochemical attributes that prevent interbreeding
Speciation happens when ?
Speciation happens when populations become separated either physically or genetically
When separated, ? can promote phenotypic and genetic divergence
When separated, genetic drift, mutations, selection, and recombination can promote phenotypic and genetic divergence
Once differences accumulate, reproductive isolation can arise via ? or ? but reproductive isolation is NOT the only outcome of secondary contact between diverging populations
Once differences accumulate, reprod. isolation can arise via selection or as incidental by-product but reprod isolation is NOT the only outcome of secondary contact between diverging populations
“reinforcement”
Reproductive isolation can be selected for if hybrids are unfit, this is called “reinforcement”
speciation = evolution of ?
speciation = evolution of isolating barriers
Conflict is _____ and can manifest itself in numerous ways, including among ___ ___ within the ____.
Conflict is widespread and can manifest itself in numerous ways, including among genetic elements within the same genome.
The absence of conflict––____––is difficult to explain evolutionarily.
cooperation
W. D. Hamilton’s theory of ___ ____ (a.k.a. kin selection theory) explains how extreme _____ (altruism) can evolve among ___ ____.
W. D. Hamilton’s theory of inclusive fitness (a.k.a. kin selection theory) explains how extreme cooperation (altruism) can evolve among genetic relatives.
Kin selection is more effective if ?
But
Not all _____ reflects kin selection.
Kin selection is more effective if organisms can identify their kin
But
Not all cooperation reflects kin selection
During the history of life, complexity _____ following a series of “_____” in which “individuals” _____ their ability to _____ independently to form a larger collective that constituted a new type of “_____.”
During the history of life, complexity increased following a series of “transitions” in which “individuals” gave up their ability to reproduce independently to form a larger collective that constituted a new type of “individual.”
4 ways of cooperation
1 kinship
2 reciprocity
3 group selection
4 cooperation
4 total outcomes of secondary contact
1 so different that they remain distinct = reproductive isolation and maybe speciation
2 merge and mate = no speciation and lose characterisitcs
3 competitive exclusion = no speciation because one population is driven extinct
4 reinforcement because hybrid sucks
prezygotic pathway
populations accumulated differences that influence individual’s choice of mates, habitats, and/or resources
postzygotic pathway
1
2
postzygotic pathway
1 intrinsic from incompatible genes brought together in hybrid –> negative interactions –> hybrid inviability
2 extrinsic: intermediate phenotypes poorly adapted to environments
A major goal of evolutionary biology is to clarify _______
A major goal of evolutionary biology is to clarify how trait variation arises.
The environment plays a crucial role in generating___ ____through a process known as plasticity.
The environment plays a crucial role in generating trait variation through a process known as plasticity.
