Monday, 20 May 2013

3.30 describe the process of evolution by means of natural selection

Evolution is a change in species over a very long time (sometimes into different species.)
Natural selection is survival of the fittest.
What happens is:

  • A mutation occurs
  • If the mutation is beneficial, the animal will survive longer and reproduce more
  • Some of its offspring will inherit the mutation
  • These offspring will also have better chance of survival, meaning they live longer and reproduce more
  • Over a long period of time this process is repeated and gradually the mutation becomes a common gene in a species and those with the mutation become the only ones, as those without cannot compete with those expressing the mutated gene

8 comments:

  1. Hi. Please give the description of natural selection and evolution full chapter . Because i have test next week ..please please make it by 1 or 2 days... i like this site

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  2. Yeh this definition is horrendous, they are usually no less than 7 mark questions and you would get no more than 3 for this answer. Please Update!!

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  3. Living things evolve through natural selection, or ‘survival of the fittest’.

    - resources needed for living things to survive are limited. Individuals must compete for the resources, and only the fittest will survive.
    - organisms show variation, and some attributes will increase an individual’s chance of survival.
    - this individual will be able to reproduce, and they’ll be a greater proportion of their genes in the next generation.
    - so the ‘best’ features are naturally selected.

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  4. The Biology Syllabus has changed…

    Here is a New blog for the 2017 Syllabus:

    http://igcse-biology-2017.blogspot.hk

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  5. more at

    http://igcse-biology-notes.blogspot.hk/2017/06/330-describe-process-of-evolution-by.html

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