This wheat was bred to resist pests and diseases. Such resistances also help wheat to survive in nature.
Llamas were bred from the wild guanaco, a sure footed animal well adapted to the mountainous, cold climate where it lives. Llamas are used for their meat, as pack animals, and most noticeably, for their wool.
Breeding is similar to natural selection in a few ways. The main idea of how it works is the same: The animals with the needed traits are able to reproduce, so in the next generation these traits are more common in the population. Mutations which enhance these traits are selected for, and they are also passed on.
Because of this similarity between breeding and natural selection, Darwin's talks with animal breeders led him to think, 'If it can work for people, why can't it work in nature as well?'
Also, though breeding is done only for human purposes, sometimes traits that people breed for are also selected for in nature. Here are four examples of this:
1. Someone who wants to make goat-hair sweaters would breed goats to have long hair. If a population of goats lives in a cold climate, they could evolve long hair to stay warm.
2. A farmer might breed his wheat (or any other kind of plant or animal) to be resistant to pests and diseases, so that more of the plants survive. The wheat evolves immunities to diseases and pests naturally to be able to survive and reproduce.
3. People breed dogs for enhanced sense of smell, so that they can help people hunt animals or search for things. Dogs have and do evolve a strong sense of smell naturally, because it helps the dog to find prey and sense danger.
4. Flowers are often bred for brighter colors or a stronger scent for bouquets and other floral arrangements. Colors and scent are also selected for naturally, because the flowers that are brightly colored or have a strong, pleasant smell are the ones that attract the most bees, butterflies, and other pollinators, so they are able to reproduce.
These similarities are caused by the fact that people begin using organisms because of traits that they already have, and then breed them to enhance these traits.
Even though man and nature have different motives, sometimes they use the same means to meet their goals.
This sheep's wild ancestors had a lot of hair, and sheep have been domesticated and bred for generations to take advantage of and enhance this trait.