When the ranges of two different species meet, a stable "hybrid zone" occupied by hybrid individuals may form. How is this possible? Two diverged populations are capable of mating and producing viable and fertile offspring. Hybrid individuals may have reduced fitness and thus be strongly selected against. Hybrid individuals are always allopolyploid and are thus unable to mate with either of the original species. One species has a selective advantage, so as hybridization continues, the other species will go extinct. Request Answer Submit

Which of the statements are true regarding hybridization? Select all that apply. Hybridization involves the transfer of genetic material between members of similar species. Natural selection sometimes acts against progeny that result from hybridization. Hybridization occurs in plants more often than in animals. Hybridization can result in fertile offspring. Hybridization cannot result in the formation of new species.

The Forbes sea star and common sea star are broadcast spawners that are known to hybridize, yet they exist as separate, genetically distinct species (unique branches on the tree of life). One mechanism that may contribute to their uniqueness is prezygotic reproductive isolation, which is the incompatibility of gametes (sperm and eggs) from separate species. We know they hybridize, so the eggs and sperm are compatible, but could gametes from the different species be less compatible than the gametes from each individual species? Harper & Hart (2005) addressed this question in a series of cross-fertilization experiments. Did they find evidence that gametes ‘preferred’ to cross with gametes of the same species? Explain your answer.

a) How many of the gene trees do you expect to look like the species tree? b)  You observe three gene trees in which species X and Z are the closest relatives and seven gene trees where X and Y are the closest relatives. What can you conclude from these data? Group of answer choices Historical hybridization between species W and X Historical hybridization between species X and Y Historical hybridization between species X and Z Historical hybridization between species Y and Z

Which of the following forms of reproductive isolation illustrates a prezygotic barrier to gene flow? O Species A forms hybrids with species B and the hybrids are able to breed back with either of the two parent species to produce healthy fertile offspring. O Two closely related birds, the lazuli bunting and indigo bunting, sing similar songs to attract mates and even though human ears can not distinguish them the females never make wrong choices in choosing who to mate with. O Two species of turtles living in a large lake have different ecological requirements and never interact. O Several species of corrals in a Honduras corral reef release gametes about the same time but inter- specific attraction of gametes does not occur. O All but one of these illustrates a type of prezygotic barrier to gene flow.

Two species of plants grow along a mountain slope. One species grows mainly at low altitudes, and the other grows mainly at higher altitudes. Occasionally, the two species hybridize producing hybrids that are better suited than the parental species to grow at intermediate altitudes. This scenario would lead to   Question 7 options:   reinforcement   autopolyploidy   a stable hybrid zone   hybrid breakdown   the fusion of the two species

Within a population of sunflowers, a new individual has a novel dominant mutation that causes it to flower 4 months earlier than the rest of the population. That sunflower survives and successfully self-fertilizes, leading over time to a novel population that evolves larger leaves and smaller flowers. This new population does not interbreed with the original population, although they are found in the same areas. This is an example of Allopolyploid speciation O Behavioral isolation O Allopatric speciation O Sympatric speciation O Adaptive radiation

cross between two fish species occurs but the developing embryo does not develop. O Hybrid inviability O Developmental isolation O Hybrid sterility O None of the above

Hello! I need help. Thanks! I'm pretty sure there's more than 1 correct answer.

A population of interbreeding birds has been split by a geological event after which the isolated part of the population started to evolve into an incipient species with different mating rituals. Due to a recent environmental change the two populations are now able to potentially mate again in what is called a hybrid zone. Mating does take place every now and then but the hybrid offspring appear less able to survive. As a consequence, mating rituals start to diverge even further. We call this process of continued divergence? O Fusion O Behavioral isolation Reinforcement O Postzygotic isolation O Stability