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Lv 6

Christians, what do you believe about micro evolution?

2 Answers

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  • Tiger
    Lv 7
    7 years ago
    Favorite Answer

    Microevolution is an uncontroversial, well-documented, naturally occurring biological phenomenon. It happens every day. It is the process whereby preexisting genetic information is rearranged, corrupted, and/or lost through sexual reproduction and/or genetic mutation producing relatively small-scale (“micro”) changes within a population. Two long-haired dogs producing a short-haired puppy would be an example of microevolution (we’ll look at why in a moment).

    We will begin with microevolution. Let’s say, for example, that within the dog genome there are both a gene for long hair (H) and a gene for short hair (h). Now imagine that the very first dogs possessed both genes (Hh). If two Hh dogs bred, half of the Hh from one dog would combine with half of the Hh from the other dog through sexual reproduction, and there would be four possible outcomes for offspring: HH, Hh, hH and hh puppies.

    Now let’s suppose that the longhair H gene is the dominant gene and the shorthair h gene is the recessive gene. That means that when a dog possesses both genes, only the longhair H gene will be expressed, i.e., the dog will have long hair. So, if two longhair Hh dogs bred, the odds are that they would have three longhair puppies (HH, Hh and hH) and one shorthair puppy (hh). The two longhair dogs having a shorthair puppy would be an example of change within a population resulting from the rearrangement of preexisting genetic information (i.e., microevolution).

    If a longhair Hh dog bred with a shorthair hh dog, the odds are that they would have two longhair puppies (Hh and hH) and two shorthair puppies (hh and hh). If two shorthair hh dogs bred, they would produce only shorthair hh puppies. And if this group of shorthair hh dogs became isolated from the longhair HH, Hh and hH dogs, they would lose access to the longhair H gene altogether and become an “isolated gene pool.” When it comes to dogs, isolated gene pools are called “purebreds.” Likewise, if a group of longhair HH dogs became isolated from the shorthair h gene, they would be considered purebred. On the other hand, the longhair Hh and hH dogs would be called “mutts.” Human breeders have been exploiting this biological phenomenon for thousands of years, selecting dog couples to mate based on their appearance in order to accentuate and attenuate traits gradually over time and thereby introduce new breeds.

    Genetic Mutation

    Now imagine that, within a longhair Hh population, a genetic mutation disabled the expression of the longhair H gene, and that mutation was reproduced over and over again within the population. The formerly longhair population would become shorthair, not because of the rearrangement of genes through sexual reproduction but because of genetic mutation.

    Another important example of microevolution through genetic mutation is when a population of insects becomes resistant to a certain pesticide, or when bacteria become resistant to antibiotics. What happens in these instances is that through mutation the insects or bacteria lose the ability to produce the enzyme which interacts with the poison. The pesticide or antibiotic, therefore, has no effect. But the insects or bacteria don’t gain any new genetic information; they lose it. It is not, therefore, an example of macroevolution as it is often misinterpreted, but of microevolution. As biophysicist Dr. Lee Spetner explains, “All of the mutations that have been examined on a molecular level show that the organism has lost information and not gained it.” (“From a Frog to a Prince,” documentary by Keziah Films, 1998)

    MIMI

  • 7 years ago

    That was a good answer. Here's the simpler answer. Well duh.

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