How do organisms evolve to suit the environment?

  • Thread starter Thread starter Yamna S
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Yamna S

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someone please explain in simple words how this phenomenon takes place. I know that evolution takes place by mutation and mutation takes place by chance. If it so happened that the organism during its development was faced with a mutagen, its genetic makeup would be affected. However this kind of mutation happens by chance (in a natural setting). It happens by chance and is infrequent.

So how does it work when an organism evolves to suit the environment? I mean, theres gotta be a contributing factor, right?
 
random mutations, and genetic recombination causes creatures to be slightly different from their parents, natural selection "filters" those differences so only the beneficial differences stay in the population.

there is a significant amount of mutations simply due to the fact that DNA replication isn't perfect, you don't need to look at outside sources like radiation or toxic chemicals.

here's some data on the subject:
"Very large mutations are rare, but mutations are ubiquitous. There is roughly 0.1 to 1 mutation per genome replication in viruses and 0.003 mutations per genome per replication in microbes. Mutation rates for higher organisms vary quite a bit between organisms, but excluding the parts of the genome in which most mutations are neutral (the junk DNA), the mutation rates are also roughly 0.003 per effective genome per cell replication. Since sexual reproduction involves many cell replications, humans have about 1.6 mutations per generation. This is likely an underestimate, because mutations with very small effect are easy to miss in the studies. Including neutral mutations, each human zygote has about 64 new mutations . Another estimate concludes 175 mutations per generation, including at least 3 deleterious mutations"
 
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