Here's why:

* Evolution is not about organisms changing "into" something else. Evolution is about populations of organisms changing over many generations due to natural selection.

* Organisms don't change their species within their lifetime. The changes we see are the accumulation of small changes in genes within populations over very long periods.

Here's an example:

* A dog does not "change" into a cat. Dogs and cats are different species and have evolved on different lineages for millions of years.

* A single dog will not evolve into a different breed. However, if a population of dogs is bred over many generations for specific traits, the population as a whole may change.

Key takeaway: Evolution is a gradual process of change in populations over many generations, not a transformation of one individual into another.