Selective Breeding

Selective breeding is also known as artificial selection. It is the process by which humans breed plants and animals for particular genetic characteristics. We have been doing this for thousands of years - ever since we first bred food crops from wild plants, and started domesticating animals about 10,000 years ago. This is when we made the transition from hunter-gatherers to farmers. We no longer needed to wander around to gather food supplies. Agriculture allowed fewer people to provide more food. Regular, predictable food production led to increased populations, and density of people. People now had time to travel, trade and communicate. Settlements began growing; the first villages and then cities were built near fields of domesticated plants. Civilisation was founded upon selective breeding! How does selective breeding work? Parents with the desired characteristics are selected from a mixed population, and are bred together. From the offspring, those with the desired characteristic are then also bred together. This continues over many generations until all the offspring show the desired characteristic. The desired characteristics that we select for can be chosen for usefulness or appearance. We just keep breeding and selecting and breeding once more until we hit the desired jackpot. By inbreeding parents that are genetically very closely related, negative outcomes can arise. The offspring will all share very similar genes, which could make some diseases more dangerous as all individuals would have the same weaknesses. The reduced gene pool also means they are more vulnerable as they have less chance of being able to adapt to changes in the environment, such as climate change. There's also an increased risk of genetic disease caused by recessive genes. Being genetically very similar, if both parents carry the recessive gene for a genetic disease, like cystic fibrosis, then the offspring will all inherit this disease. We have been selectively breeding for thousands of years, getting closer to our desired goal with each generation of offspring. Nowadays, we have come up with a faster way to do it… genetic engineering. We can transplant the genes for a desired characteristic straight into an organism.