This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American
Homo sapiens is a dominating species. We have a marked tendency to mould other species to better suit our own needs. The human orchestration of animal evolution through domestication is an interesting and very real concept that pervades our everyday lives. From the meat we eat, to the clothes we wear, lots of things originate from animals that have been subjected to our somewhat selfish desires to make them prettier, make them meatier or make them friendlier.
Making animals prettier
Unusually-featured animals, or those perceived as being particularly attractive based on human ideologies, are often highly prized. Take the pig. Or rather, the colour of the pig. Pigs never used to have black spots or stripes until a genetic variation popped up independently in both Asia and Europe (two separate mutations at two different areas of the same skin colour gene). Black spots on a pink skin made pigs stand out, and in the wild they would have been quickly eliminated by predators. In a domestic setting, though, the spots were instantly admired, and so purposefully bred into the wider pig population. Now, spots are peppered through breeds all over the world, including the Ukraine, United Kingdom, USA and Belgium.
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Making animals meatier
Most omnivorous humans have a deep and abiding love for a nice plump piece of meat. Consequently, lots of creatures we like to eat have been selectively bred to ensure such appealing cuts end up on our plate. Chickens, for example, which offer two different edible products, have been bred from the original wild red jungle fowl down two distinct evolutionary paths to perfect both products separately. We breed either big chunky broiler birds for meat or delicately fertile layer birds for eggs. Broilers have big changes in genes involved in growth, appetite and metabolism, and consequently eat more, burn more fat and put on muscle at a faster rate. Layers have been genetically honed to excel at diverting nutrients from food into egg production, and generate a small mountain of eggs every year.
Making animals friendlier
Employing a carnivorous animal to guard your property, help you hunt or simply keep your feet warm on a cold Winter's night is a trusting business where it's reassuring to know that your own meat won't appear on the menu. Take man's best friend, the dog, who is the product of 10,000 years of domestication from the wolf. The DNA of wolves and dogs currently differs at 36 chromosomal regions. These genetic changes translate into dogs having obvious physical differences - smaller skulls, teeth and brains - but also behavioural changes that make them much less aggressive and more sociable towards other species. Genes involved in digestion are also modified in the modern canine, and appear to have evolved to allow adaptation from a mainly meat-based diet to one rich in starch, ultimately making it easier to survive on human food.
Making animals futuristic
So, it's easy to see that we humans are selfish beasts. Yet we're also ingenious ones. Since breeding, growing and harvesting or training animals can be a hugely expensive, environmentally-damaging and time-consuming process, we have begun to explore the possibilities of harnessing science to create ready-made animals with a full complement of desired genetic attributes, or to produce tasty bits of animals in a dish (see this excellent article on synthetic meat). This is a thoroughly exciting and burgeoning area of research, but whether it will improve or worsen our previously questionable approach to interacting with other animals might be a close call.
Image:Andrew Becraft on Flickr.