Organisms have gradually adapted certain structures that help them succeed in their environments. What internal structure have birds developed that helps them successfully fulfill their niche?

the second type of galaxy is called a barred spiral, which has a thing called a bar straddling the nucleus

•there must be variation for the particular trait within a population.

•the variation must be inheritable (that is, it must be capable of being passed on from the parents to their offspring).

•individuals with one version of the trait must produce more offspring than those with a different version of the trait.good

explanation: