Question

Question: 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 prezyogotic 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?

Answer 1

Through evolution study we are clear that couplation between similar species is much compatable then other species for this further releveant evidence are identity like mechanisms of selling prezygotic reproductive isolation and their prevalence are key measure in modern biology because of their ability position in speciation. In marine broadcast-spawning species, molecular interactions between gamete surface proteins are extra essential than mating conduct for figuring out reproductive compatibility. Proof for differential fertilization ability between different species has been stated from experiments utilizing sperm from men sampled within populations and among species, however to know-how conspecific populations that would have diverged in allopatry have never been examined on the idea of sperm competition. In the present examine, the gametic compatibility and embryo survivorship from matings among two allopatric populations of crassostrea virginica were done, the jap oyster, on both aspect of a genetic step cline were investigated. Fertilization experiment shows, embryo survival, and paternity statistics all indicated a scarcity of sturdy reproductive limitations between the two oyster populations, implicating other mechanisms for upkeep of the cline step. Sperm from northern male oysters species confirmed a bent to produce much more larvae than anticipated when competing with sperm from southern male oysters. Despite the fact that the northern male gain was no longer sturdy, the trend means that lengthy-distance dispersal throughout the step cline might more correctly bring about north-to-south gene go with the flow than the reverse, offering a mechanistic hypothesis explaining the uneven cline form.This study conclude that genetic variation and species couplation varry with the distance as well as species difference also.