speciation LRQ
there are no rules for how many genetic differences are needed to distinguish different species.
A disadvantage of using DNA or RNA sequences to identify species is that
habitat isolation
American sycamore (Platanus occidentalis) and European sycamore (Platanus orientalis) are tree species that will interbreed if planted nearby but will not normally interbreed because they occur on different continents. This is an example of
sympatric speciation
At some time within the last 10,000 years, a population of the white trout lily, Erythronium albidum, gave rise to a new species, Erythronium propullans. Both species are still living and the geographic range of E. propullans is, and always was, entirely within the geographic range of the widespread E. albidum. This appears to be an example of
sympatric speciation and diversifying selection
In a hypothetical situation, a certain species of flea feeds primarily on pronghorn antelopes. In the western United States, pronghorns and cattle often associate with one another in the same open rangeland. Some of these fleas develop a strong preference for cattle blood and tend to mate with other fleas that prefer cattle blood. If this situation persists, and new species evolve, differentiated by food preference, this would be an example of _____.
calls would be more different in areas of sympatry
Male frogs give calls that attract female frogs to approach and mate. Researchers examined mating calls of closely related tree frogs in South America. If behavioral isolation is occurring where the two species overlap geographically, what would you expect if you compare the calls of the two species in zones of sympatry versus zones of allopatry?
poses a greater fitness cost to the parent
Prezygotic isolation mechanisms are more comment than postzygotic isolation mechanisms because postzygotic isolation...
the tetraploids would be reproductively isolated from both parent species
Researchers experimentally formed tetraploid frogs by fertilizing diploid eggs from Rana porosa brevipoda with diploid sperm from Rana nigromaculata. When they mated these tetraploid frogs with each other, most of the offspring that survived to maturity were tetraploid, with chromosome sets of both diploid parent species. Based on these results, if this type of tetraploid formed in the wild, what would be the result?
evolutionary independence
The general lineage species concept emphasizes
Hybrid offspring have higher mortality rates than non-hybrid offspring.
Two similar species that were geographically isolated have now come into contact. Given that hybridization can occur, which one of the following would be most likely to lead to the evolution of reproductive isolation in these two populations?
reproductive isolation
What does the biological species concept use as the primary criterion for determining species boundaries?
horizontal gene transfer
What mechanism makes it difficult to classify bacteria into distinct species groups based on a biological or genetic species concept?
punctuated equilibrium
When a species arrives in a new location it may undergo relatively rapid adaptive radiation, diversifying and filling a new set of available ecological niches. Such an event may help to explain the phenomenon of:
prezygotic isolating mechanism
When cross-pollination is attempted between two closely related species of violets, it is found that the pollen of species A cannot reach the egg of species B because it lacks the proper enzyme to travel down to the location of the egg. Likewise, the pollen of species B cannot reach the egg of species A. This phenomenon is an example of
Which of the following does NOT tend to promote speciation?
gene flow
involves an increase in the number of chromosomes.
polyploidy