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What makes all the genitic coding in nature?

During evolution what is the factor that makes new codes or modifies the existing one?

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  • 7 years ago
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    Biologists know of several natural processes that can add new genetic information to genomes, some of which are (1) gene duplication followed by divergence, (2) exon/domain shuffling, (3) lateral gene transfer, (4) endosymbiogenesis, and (5) de novo gene formation.

    Here are some English-language analogies for 2 of those.

    1. Gene duplication followed by divergence can add genetic information to genomes.

    Here’s an English-language analogy.

    Gene A

    TOWER

    Gene A gets duplicated

    TOWER TOWER

    One copy is mutated to a new, functional sequence

    TOWER POWER

    Of course a new, functional sequence is not always the result of mutations accumulating in a copy. The other possibility is that the mutations produce a non-functional copy: a pseudogene.

    Gene A

    TOWER

    Gene A gets duplicated

    TOWER TOWER

    One copy is mutated to a new, non-functional sequence, becoming a pseudogene

    TOWER TZWER

    In 2008, counts showed that the human genome has nearly as many pseudogenes as it does protein-coding genes, and the prediction is that it will end up with more of the first than the second.

    Gene families arise by multiple rounds of duplication and divergence.

    Gene A

    TOWER

    Gene A gets duplicated

    TOWER TOWER

    One copy is mutated to a new, functional sequence

    TOWER POWER

    Gene B gets duplicated

    TOWER POWER POWER

    One copy of Gene B is mutated to a new, functional sequence

    TOWER POWER POKER

    Gene A gets duplicated

    TOWER TOWER POWER POKER

    One copy of Gene A is mutated to a new, functional sequence

    TOWER TOWED POWER POKER

    Gene D gets duplicated

    TOWER TOWED POWER POKER POKER

    One copy of Gene D is mutated to a new, functional sequence

    TOWER TOWED POWER POKER JOKER

    Many such gene families are known.

    2. Exon shuffling can also add genetic information to genomes.

    Here’s an English-language analogy.

    Starting genome, with exons separated by ---.

    ADORN---MENT

    IM---POSSIBLE

    PROVE

    The IM exon is shuffled in front of the PROVE exon.

    ADORN---MENT

    IM---POSSIBLE

    IM---PROVE

    The MENT exon is shuffled to the back of the PROVE exon.

    ADORN---MENT

    IM---POSSIBLE

    IM---PROVE---MENT

    So "PROVE" has changed to "IMPROVEMENT": an increase in information. Further, because of alternative splicing, all three forms could be expressed: PROVE, IMPROVE, and IMPROVEMENT.

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  • 7 years ago

    There are a few mechanisms which account for genetic coding and variation. For example, in humans, during Meiosis, we can find CROSSING OVER in Prophase I (where homologous chromosomes exchange genetic information by "rubbing against each other") and INDEPENDENT ASSORTMENT in Anaphase I (where the homologous chromosomes assort independently into each sex cell).

    Also, there are natural mutations that can occur that can change the genetic code.

    Source(s): B.S. in Biology
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  • 7 years ago

    Mutation!

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