Charles darwin reached following conclusions (1) variation exists in natural populations. (2) many more offspring are born each season than can possibly survive to maturity. (3) as a result, there is a struggle for existence (4) characteristics beneficial in the struggle for existence will tend to become more common in the population, changing the characteristics of a species. (5) over time, and given a steady input of new variation into a population, these processes lead to the emergence of new species. these conclusions, from the origin of species, was coupled with:

Natural Selection

Explanation:

The later findings of Darwin's were clubbed with his theory of natural selection as its process components -

1.Variation – Darwin said that all organism  vary from each other in terms of appearance and behavior within and outside their species. Some feature vary completely while some features (such as number of eye) do not vary at all.

2.Inheritance – The traits that are responsible for any physical trait are passed on from parents to their children generation after generation. However some traits are also encouraged to appear as a response to environmental condition

3.High rate of population growth- High rate of population growth causes competition with in the species for resources. This competition leads to the survival of the fittest

4.Individuals which have traits suitable for survival in a given scenario produce more offspring to the next generation.  

the correct answer is sex-linked recessive.

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