Why dies???? what do you mean
A it can be lost during an organisms lifetime
<span>In biological terms, the structure of a species is usually best adapted to give it the most advantageous functional ability, though this is not always the case. When a structure has a function that allows the species to survive and promulgate its genetic structure, the individual will be more likely to reproduce its genotype over those that are not structurally advantageous.</span>
From it's environment and from traits from other parents.
