Please answer question 7....
don't delete...

Dear Student, At individual level an organism is not evolving but is ageing means that evolution cannot be defined at individual level. With the passage of time an individual ages i.e grows old but does not evolve into another type of organism or species. The statement variation is beneficial to the species but not necessary for the individual can be explained as: Variations are beneficial to the species than individual because sometimes for a species, the environmental conditions change so drastically that their survival becomes difficult. For example, if the temperature of water increases suddenly, then most of the bacteria living in that water would die. Only few variants that are resistant to heat would be able to survive. However, if these variants were not there, then the entire species of bacteria would have been destroyed. Thus, these variants help in the survival of the species. Note that here variation is also beneficial for individuals also. However, all variations are not necessarily beneficial for the individual organisms. There are some harmful variations also. Suppose there occurs mutation in the genes of some bacteria that resulted in non functional enzyme that helps in synthesis of proteins. Thus, only those individuals will die which posses harmful variation and rest of individuals will survive and continue the species. Thus, species always survives whether variation is beneficial or harmful but individual survives only when there is beneficial variation. Thus, we can say that variation is beneficial to the species but not necessary for the individual. Regards