How can natural selection account for the long necks of giraffes?

Due to natural selection, the long-neck trait survived and was able to pass on the long-neck allele because there was enough food for these giraffes to survive. Alternatively, the short-necked giraffes were eliminated because the short-neck trait prevented them from obtaining a sufficient amount of food in order to survive.

bai :>

parasites can detrimentally affect their host, but also must not allow their host to die before they can complete their life cycle. some parasites have complex life cycles with many different hosts, and have had to find ways of persisting in many different environments during the change from one host to another. ectoparasites live outside the body of the host, and can more easily  disperse, but are  more exposed to predators, parasites, parasitoids. endoparasites live inside the body of the host, and are therefore protected from the outside environment. but they can be  attacked by the host's immune system. they have therefore developed  mechanisms for dispersal such as  complex life cycles.

it takes hundreds of years to become stable.

if you have another question lmk.