Selection

For a species to survive and prosper, it must be adapted to the environment; and the environment is constantly changing. Species of plants and animals that exist today are the ones that have changed to be capable of living in the presence of harsh environmental conditions, pests, and parasites. The mechanism for change is mutation. Mutation of genes means different traits will be passed along to the next generation. If these traits make it more favorable for the offspring to live, there will be more of the offspring in the population. This change in the numbers of individuals with certain traits describes how plants and animals evolve to fit into the changing environment. This population change is the result of natural selection. Humans can artificially select the characteristics that we feel are wanted by picking the individuals that we want to reproduce. Beekeepers are doing this by selecting honey bees that are resistant to parasitic mites and other pests and pathogens. They are also selecting bees that are gentle and are effective pollinators and honey producers.

Horticulturist Paul Little is selecting varieties of the succulent plant, sedum, which are well adapted to the environment in the Southern United States. His method involves attempting to grow large numbers of sedum plants and evaluating how well they perform in the region’s warm, humid temperate climate and varying soil conditions. Of course, many of the varieties that Paul tries simply die. They are not suitable in the region. Paul propagates sedum from the heartiest survivors. His plants are identified as Southern Select Sedum, and may be viewed at http://www.southernselectsedum.com/. The method of improving the survivability of either honey bees or sedum plants is similar. Honey bee producers probably have an advantage over sedum producers because the multiple mating of queen bees results in a numerous traits to select. Sedum plants are propagated by cuttings. The offspring plants from cuttings are clones of the parent plant without genetic differences to select.
--Richard