Selective Breeding
Selective breeding means to select individuals with desirable characteristics and breed them together
The process doesn’t stop there though because it’s likely that not all of the offspring will show the characteristics you want so offspring that do show the desired characteristics are selected and bred together
This process has to be repeated for many successive generations before you can definitely say you have a ‘new breed’ which will reliably show those selected characteristics in all offspring
Selective breeding in domesticated animals
An example of selective breeding is dog breeders who select which dogs can mate together to increase the likelihood of puppies displaying desirable characteristics eg. coat colour
This has given rise to the many recognisable dog breeds of today, all the same species (Canis familiaris) and all descended from one breed
Selective breeding in crop plants
Plants are selectively bred by humans for the development of many characteristics, including:
disease resistance in food crops
increased crop yield
hardiness to weather conditions (e.g. drought tolerance)
better tasting fruits
large or unusual flowers
An example of a plant that has been selectively bred in multiple ways is wild brassica, which has given rise to cauliflower, cabbage, broccoli, Brussels sprouts, kale and kohlrabi: