Question

how are variation useful answer in long.?

Answer 1

overproduction of offsprings by organisms will lead to limited resources which will further lead to struggle for existence.during this time, some variations are found each species which may be favourable or unfavourable.the organisms with favourable variations survive and sustain the species whereas the organisms with unfavourable variations get eliminated.this is why it is said that variation is useful for the survival of species over a long time but the variants have unequal chances of survival.

Answer 2

*Variations may prove to be advantageous or disadvantageous to the variant as the life span of the individual is so small. Variations acquired by the variant are not easily acceptable. Variant with variations is not easily accepted into the group. Only advantageous variations occurring in a variant are able to exist in population.  
*Variations are selected through natural selection, so not all the variations in a variant have equal chances of survival.

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Variations are the changes caused in the genetic material thereby bringing about changes in the offspring. Variations caused by mutations can be beneficial or detrimental.

*Variations are advantageous to species as the changes which are acquired by variations are inherited by the offspring and certain alterations occur over many generations to make the changes acquired by variations perfect.

*Variations may prove to be advantageous or disadvantageous to the variant as the life span of the individual is so small. Variations acquired by the variant are not easily acceptable. Variant with variations is not easily accepted into the group. Only advantageous variations occurring in a variant are able to exist in population.  

*Variations are selected through natural selection, so not all the variations in a variant have equal chances of survival.

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