The Pros And Cons Of Artificial Selection

1668 Words7 Pages
1 )artificial selection in current world?
Answer : Artificial selection is the process of changing the characteristics of animals by artificial means. It was originally defined by Charles Darwin in contrast to the process of natural selection, in which the differential reproduction of organisms with certain traits is attributed to improved survival and reproductive ability in the natural habitat of the organism. For example, animal breeders are often able to change the characteristics of domestic animals by selecting for reproduction those individuals with the most desirable qualities such as speed in racehorses, milk production in cows, trail scenting in dogs. Another example is the crossing of white corn, or field corn, with yellow corn,
…show more content…
In his essay for that series, Jeff Schloss addressed the question of whether animal death is a natural evil, but also noted that such theological considerations aside, death does not actually “drive evolution” in the way most people imagine—especially when they think of violence in the natural world. This more complicated sense of death’s role is partially the result of modern evolutionary science recognizing the importance of cooperation and inter-relation among species, rather than just direct competition. But just as important is the knowledge that evolution is significantly shaped not by the deaths of individual creatures, but by extinction, the loss of species over time. In this post, we explore some aspects of how extinction acts as both a destructive and creative force in evolutionary history, including the evolutionary history of mammals.
4)all living organism still share the same genetic code ..?
Answer : Comparing genetic duplications in genes, the number lowers to 96%.
What's a duplication? As Even Eichler of University of Washington says, if we consider the genetic code as a book, entire pages will be repeated in one species but not the other. So conservatively, we are 96% alike with out closest
…show more content…
Darwin brilliantly addressed this argument by surveying existing species to see if one could find functional but less complex eyes that not only were useful, but also could be strung together into a hypothetical sequence showing how a camera eye might evolve. If this could be done—and it can—then the argument for irreducible complexity vanishes, for the eyes of existing species are obviously useful, and each step in the hypothetical sequence could thus evolve by natural selection.’6
The dominant theory was outlined by Dennett, who concluded that all eye evolution requires is a
‘ … rare accident giving one lucky animal a mutation that improves its vision over that of its siblings; if this improvement helps it to have more offspring than its rivals, this gives evolution an opportunity to raise the bar and ratchet up the design of the eye by one mindless step. And since these lucky improvements accumulate—this was
Darwin’s insight—eyes can automatically get better and better and better, without any intelligent designer.’7
Others are not so confident. Melnick concluded that the eye is
Open Document