Question

why is variation beneficial to the species but not necessary for an individual ?
explain with help of suitable examples?

Answer 1

this is true because for eg - a population of bacteria is living in a water body , suddenly there are some climatic changes ,  may be possible the temperature of water body rises , due to which some of the bacteria die but some will not because during that time some variations are created in the new offspring which helpful for that specie

Answer 2

The variation is important and beneficial for species as it allows a species to adapt to a changing environment.

For example, climate change can force a species to shift its range to poleward or to higher altitudes.

Only those who adopt the changes can survive in harsher conditions by adapting to the changes.

For an individual, the variation doesn't matter in most of the conditions.

Take the example of we humans, if a climate change happens, we can shed our clothes and our body will help us control the temperature, and if the environment gets colder, we can wear more clothes to protect us.

However, in conditions like any new virus or bacteria attack which is harmful to humans, our body has to adapt according to this scenario or we will perish.