The Human-Made World
The humble apple, something that we in developed nations take for granted, has a long and interesting history, and one that you are probably not aware of. The apple we see today comes in many varieties, from Red Delicious, to Granny Smith, to Gala and Fuji, but they all stem from a single plant which we have changed and customised to our palette’s desires over centuries. There are subtle variations in colour, flavour, texture and smell in the world of apples, just as there are many usages for these apples. The red apple, commonly used in early childhood development to represent colour in picture books, and also to represent the letter “A” as the first letter in the alphabet, is unlike any apple that evolved naturally, and our role in developing this fruit to its current state took centuries. So where did it come from, and how did it get to its current shape, texture, flavour and colour? And what do they have in common with the rose bush outside your house?
The apple tree originated in Central Asia, and was a small inedible fruit from a relative of the rose bush, Malus sieversii, and has been cultivated over centuries in the mountainous areas of China. The first apples known were small and pithy, and resembled crab-apples. Through thorough selection and interbreeding, the apple became large and delicious to our palate, now represented by over 7,500 different cultivars. The apples we see today were brought to Europe and the Americas along trading routes such as The Silk Road, and are now a staple of foods worldwide. All apples still retain the 5 lobed flower, some with multiples of petals, but always 5 sets. Likewise, every apple is divisible into 5 segments, each containing between one and five seeds. The apples we eat may be called perfect, but our meddling with their genetics has a a limitation, being that we can’t cultivate the same apple “type” from the seed of the apple. Due to interbreeding and cross-pollination, the fruits of the apple trees deliver fruit which contains hybridised seeds, which in our product-based world are not acceptable for market. Any apple you eat that is from a single varietal comes from a cutting of the original plant, that is to say, every Gala apple tree is a clone of the original tree upon which these apples were cultivated, made from a cutting, and grafted onto a hardy rootstock.
It’s no surprise that the original apple is different to the ones we see today; humans have been changing the nature of domesticated plants and animals for centuries, and almost all plants and animals we consume only hold a vague resemblance of the plant or animal we first domesticated. Cauliflower, broccoli, brussel sprouts, and cabbage all originated from a kind of kale we don’t see in markets today, but through careful selection and breeding, we get an array of vegetables, each with their own distinct characteristics, flavours, smells, textures and properties, many of which were not present in the original kale from which they originated. Possibly the most interesting example of this group of plants is the Romanesco broccoli (pictured above) , which has fractal-like flower buds, each one a perfect mathematical geometry, seemingly created by a computer. The true nature of these plants is rarely seen in when we grow them. We harvest the leaves and flowers before they reach maturity. It’s only when we let these plants grow past their edible state, and go into flower, that the similarities are revealed. The flowers of all the aforementioned plants look much like the flowers of the mustard plant, and it’s no surprise either, since mustards, horseradish, wasabi, canola and many other plants we use for food and flavouring are all members of the brassica family. Unlike the apple, the seeds of particular cultivars of brassica will resemble the plant from which it originated, and these seeds are viable for reproduction of the plant in home gardens.
Likewise, the cows, sheep and chickens we are familiar with, and breed as foodstock, only share a vague resemblance to the animals from which they originated, and have been bred selectively over centuries to give us the animals we see today. But it’s not only foodstock that we have bent over time to our will. Domesticated pets such as the humble dog and cat are unlike their ancestors in many ways, but in particular, the dog shows the full breadth of what is possible with selective breeding. Dogs are classified as Canis lupus familiaris (with familiaris being “the one we are familiar with”), and all dogs are the relatives of a particular kind of wolf which still lives in Europe, the grey wolf canis lupus. It is suggested that over 34,000 years ago, wolves began associating with humans more as scavengers than as companions. Humans create a lot of waste, and once humans began farming and settling in one place, our garbage aculmulated in those spaces, which was a rich source of food for the wolves. Domestication of these animals was just a matter of time, as the wolves bore litters of pups around the areas which humans lived, and some were adopted by the early farmers. But it took centuries of selective breeding before canis lupus was domesticated enough to be called a companion to mankind. What is amazing about the dog is just how we as human beings have altered the look and function of dogs. From the Great Dane all the way down to the Teacup Chihuahua, every single breed has been guided by that hand of human-kind to serve a particular function, and through selective breeding, enhancing the qualities we would like to see, and removing some that we don’t want, we have ended up with over 300 recognised dog breeds. What is interesting about dog breeds is that, if they were left to their own devices and allowed to breed with any old dog, they characteristics we bred them for would eventually be diluted, and the dogs would end up looking more like the village-dogs of Borneo, or the Australian dingo. That they don’t revert back to the wolf-state is telling, and it becomes apparent that some characteristics are capable of being “bred out” of an entire species.
What we see in the world of selective breeding is a man-made example of how evolution works, but through artificial selection rather than natural selection. In the case of artificial selection, the choices of humans take the role of natural pressures in natural selection, and the resulting animals and plants have been “forced” to take on their current state, rather than adapting over time and generations as in the case of natural selection. It is precisely the same process in both cases, however selective breeding is is observable in a much shorter time-frame than natural selection, as we have chosen the characteristics we would like to see, and breed the plants or animals as soon as they are viable.
On a microscopic level, selective breeding takes on an entirely different role. In laboratories world-wide, scientists are selectively breeding everything from bacteria to insects to study a wide selection of sciences, from genetics to immunology, taking advantage of the rate at which natural and selective evolution takes place. The time-frame in which successive generations can change and mutate is much smaller in these organisms, and makes observation of the changes much easier and time efficient. Taking advantage of the natural and guided evolution of organisms in short periods of time allows us to develop medicines and treatments for many of the diseases that ail the modern world. This is modern science, and the way we guide the processes of evolution allows us to live the lives we live today. Without this, diseases like polio and smallpox would still be a bane to society.
So next time you eat an apple, or take your dog for a walk, remember that these plants and animals are here, in their current state, because humanity intervened in the natural process, and through selective breeding, has made them so. The world we live in now is much different to the one in which the species evolved, and without the ingenuity of humanity, we might all still be eating crab-apples and nearly inedible kale for our dinner.