43 Questions
According to the biological species concept, a species is defined as a group of naturally occurring populations that...
either actually or potentially interbreed and are reproductively isolated from other such groups
The focus of the biological species concept is on...
reproductive isolation
One of the problems with the biological species concept is that it doesn't apply to...
asexual organisms
The biological species concept is not applicable to asexual organisms because...
asexual organisms don't interbreed
In the biological species concept, if two populations are not reproductively isolated from each other, then...
they can potentially interbreed and are members of the same species
One of the problems with the biological species concept in relation to fossils is that...
it's difficult to determine whether the fossils could potentially interbreed
What is the Red Queen hypothesis?
Organisms evolve to keep up with other organisms
What is exaptation?
When a trait evolves for one purpose but is used for another
What is heterochrony?
A change in the developmental timing or sequence of developmental events
Which best describes neoteny?
Adults retaining juvenile traits
What is an example of exaptation?
Feathers evolving for thermal regulation and later used for flight
What best describes the Red Queen hypothesis?
Organisms evolve to keep up with other organisms
What is punctuated speciation?
Rapid bursts of speciation followed by long periods of stasis
What would not lead to punctuated speciation?
Increased rates of neutral mutations
What is the best definition of heterochrony?
A change in the developmental timing or sequence of developmental events
What is the definition of evolution?
Descent with modification
Which mechanism can lead to the reinforcement of prezygotic isolating mechanisms?
Hybrid infertility
What are the 2 theories of the debated tempo of speciation?
Punctuated equilibrium and gradualism
What follows mass extinction events, leading to rapid evolution of diverse phenotypes under new environmental conditions?
Adaptive radiation
What is the rate at which extinction is occurring compared to average historical rates?
1000 times greater
What is the definition of microevolution?
Changes in allele frequencies over time
Which event can drive rapid speciation?
Polyploidy events
Which species concept relies on DNA data to determine species membership?
Lineage species concept
What is a crucial factor in all species concepts and plays a major role in speciation?
Reproductive isolation
Which type of speciation occurs without physical or geographical separation?
Sympatric speciation
Which isolating mechanisms act after zygote formation?
Reduced hybrid viability
What does natural selection favor to ensure viable offspring capable of passing on genes?
Prezygotic barriers
What does the morphological species concept focus on for bird identification?
Physical forms of organisms
Which species concept relies on DNA data to determine species membership?
Lineage species concept
What is a crucial factor in all species concepts and plays a major role in speciation?
Reproductive isolation
Which type of speciation occurs due to physical or geographical separation?
Allopatric speciation
What prevents zygote formation as a prezygotic isolating mechanism?
all of the above
Which isolating mechanism acts after zygote formation?
Reduced hybrid viability
What does natural selection favor to ensure viable offspring capable of passing on genes?
Prezygotic barriers
Which concept is not applicable to organisms producing hybrids in captivity or existing only in the fossil record?
Biological species concept
Organisms have to evolve to get better adapted to their environments according to the Red Queen hypothesis
False
Exaptation occurs when a structure evolved for one purpose is never used for another
False
Heterochrony can give rise to speciation
True
Neoteny is when adults have retained juvenile traits
True
Increased rates of neutral mutations would lead to rapid speciation
False
The swim bladders of fish evolving from the lungs of lungfish is an example of exaptation
True
The Permian mass extinction event is considered the largest extinction event in the history of the world
True
Higher rates of extinction are expected in organisms with longer generation times
False
Study Notes
Species Concepts and Speciation
- The biological species concept is not quantifiable, leading to the exploration of alternative species concepts.
- The morphological species concept defines species based on physical appearance and is considered the simplest definition of a species.
- The lineage species concept relies on DNA data to determine species membership, with 99.9% DNA similarity often indicating the same species.
- Reproductive isolation is a crucial factor in all species concepts and plays a major role in speciation, allowing separate evolution.
- Two major types of speciation are allopatric, occurring due to physical or geographical separation, and sympatric, occurring without such barriers.
- Prezygotic isolating mechanisms prevent zygote formation, including habitat, temporal, behavioral, mechanical, and gametic isolation.
- Postzygotic isolating mechanisms act after zygote formation, such as reduced hybrid viability and fertility.
- Natural selection favors prezygotic barriers over postzygotic barriers to ensure viable offspring capable of passing on genes.
- The biological species concept is not applicable to organisms producing hybrids in captivity or existing only in the fossil record.
- Field guides for bird identification are based on the morphological species concept, focusing on physical forms of organisms.
- The biological species concept cannot group fossils or asexual organisms into species.
- Habitat isolation, as seen in black bears and brown bears, prevents interbreeding by keeping species in different habitats and niches.
Test your knowledge of mechanisms of speciation, tempo of speciation, and extinction events with this quiz. Explore concepts such as hybrid infertility, natural selection, microevolution, macroevolution, mass extinction events, and adaptive radiation. Delve into species concepts and speciation, including the biological species concept, morphological species concept, lineage species concept, reproductive isolation, allopatric and sympatric speciation, prezygotic and postzygotic isolating mechanisms, and the application
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