5 Surprising Ways Humans Influenced The Evolution Of Other Living Things
by Rori Porter
Genetically modified organisms. To some, this string of words conjures images of scientists injecting shark DNA into soybeans. The reality, however, is typically far more mundane than that. Most modified crops are the result of selective breeding experiments over time -- it’s less evil scientist and more grandma fussing around with carrot hybrids until one pops out purple. That said, some of humanity's simplest explorations in plant and animal selective breeding has resulted in some seriously weird and/or cool stuff.
Six Different Vegetables All Come From The Same Plant
Unless you subsist on a diet approved by all four Ninja Turtles, chances are your grocery list has some kind of vegetable on it -- if only to make you feel like you’re succeeding at adulting before cramming Coco Puffs and Gushers into your eat-hole. Hey, we’re not judging. But what you may not know about that broccoli and kale is that they’re not so distant relatives. In fact, they (and quite a few other vegetables) come from a single plant that humans nudged in different directions.
Brassica oleracea is the most common vegetable genus you probably didn’t realize you eat all the time. In the last few hundred years, this plant, wild mustard, has been cultivated in different ways to produce six different vegetables: Brussels sprouts, cabbage, kale, broccoli, cauliflower and kohlrabi. That is to say that without humans, none of those vegetables would exist. At least not as we know them.
It's also how Miley Cyrus was created.
And because Brassica is basically the Mystique of plants, it doesn’t stop there. Kale, for example, is enormously hardy and can be grown from early spring up until the first freeze of winter, and most people yank the plant after the season is over. However, you can actually winterize it, and when spring hits the following year, it develops flowering buds that are completely edible and taste very similar to broccoli, only milder. So if you’re the gardening type, don’t give up on kale when the season is over. With a little patience, you could have what is like a whole new vegetable: some delicious little mini-broccolis.
We Had To Make New Bananas, Papayas And Potatoes Because Of A Crop-Killing Fungus
Most food we eat is quite unlike the food we ate years ago due to selective breeding, natural cross-breeding, and sometimes Jordan Breeding. Sometimes we do this just because we want a freaking limequat, dammit. Other times, however, our hand is forced, like when invasive fungi try to wipe out our favorite foods.
Take the Gros Michel banana -- it was almost completely killed off by Panama disease, a wilt caused by the fungus Fusarium oxysporum. Once the darling of the international fruit market, the Gros Michel is described as tasting creamier and more robust (basically more banana-y) than the ones we enjoy today. Farmers were initially reluctant to stop farming the susceptible crop, because the alternative Cavendish was considered to be a “junk banana” due to its inferior taste.
That sh*t is bananas. B - A - N - A - N - A - S.
They were forced to give in, however, as Panama disease decimated entire crops while the Cavendish was resistant to the fungus. But as Earth has a history of demonstrating just how fragile our lives are on its flimsy surface, Panama disease has returned, this time with a new strain and its sights set on our beloved, less flavorful Cavendish bananas. Which could be problematic, specifically because we currently have no commercial replacement for the Cavendish, so we may have to breed a completely new resistant version if we want our Cheerios to be less depressing.
We’ve had to take this same approach with potatoes to prevent a repeat of the Great Famine in Ireland, and with papayas to help protect a crucial Hawaiian export. Because even when we try to put the muscle on nature, it always seems to be able to counter with a groin kick.
World War II Gave The Planet A Brand New Mosquito
In all likelihood, mosquitoes have existed on this planet far longer than we man-apes, and their presence has always been a tiny annoying jab in our collective sides. During World War II when citizens were forced underground to hide from bombs, the mosquito population followed them into the tunnels. There, generations of mosquitoes have bred away from their surface-dwelling brethren. And since mosquitoes live for about three weeks, their generational turnover is significant, and that short lifespan equates to speedy evolution.
While not a distinct species, the Culex pipiens molestus (commonly called the London Underground mosquito) is a physiological and ecological variant of the Culex pipiens mosquito. One major difference is that the Culex pipiens prefers feeding upon birds, while the molestus mosquitos have more of a taste for humans and rats.
And this is what they get. Tell your friends.
The underground mosquitoes are an example of extremely fast moving speciation. In addition to adapting a rather ghoulish taste for, well, you, they have also adapted to live and breed in tight subterranean spaces, whereas their surface cousins require more space. They also stopped hibernating in the winter due to the more consistent temperature underground yearlong, allowing them to reproduce at any time of the year. All of these changes have even brought them to the point that they don’t even seem to get frisky with the non-tunnel dwellers.
They’ve even managed to find their way across the world, calling places like Japan and the United States home. And while we didn’t create these mosquitoes on purpose, their adaptation was because of us, even if all people were trying to do was flee from horrific death.
Humans Have Created So Many Dogs That Never Would Have Otherwise Existed
One of the most stunning examples of humanity mucking about with evolution is the amazing variation in modern dogs. As it turns out, all of the hundreds of different domestic breeds we know today are related to gray wolves. Back when humanity was still huddling around cave fires, our ancestors selectively bred tame wolves, resulting in early dogs. They bred only the cutest, tamest, strongest, and who’s-a-good-boyish wolves. It was a mutually beneficial exchange: the dogs provided us with protection and companionship, and we fed them and kept them healthy.
Well, healthy until we started breeding them into adorable little monstrosities. We’re not exactly sure how far back this practice goes, but at some point someone said, “Hey, I like that wolf’s tail and that one’s eyes. Make them do it and let’s see what we get!”
Since those early days, we have bastardized dogs to the extent that some can’t even breed on their own. The Bulldog, for instance, almost always needs to be artificially inseminated due to the dog’s morphology, resulting in an inability to perform successful humping maneuvers. And cesareans are common since the mother can be unable to deliver naturally without severe complications.
The bow-eared Easter bulldog.
Pugs are another good example, what with their adorable grunts, cute little smashed noses and inability to properly breathe. Dyspnea has somehow become a attractive trait, which ... well, we don’t know why.
Whereas we once bred dogs for things like hunting, sprinting, herding, or carrying heavy loads has been replaced with brindle coats, excessive wrinkles and hip dysplasia. But hey, at least we got the Chinese Crested out of the deal.
Fishing Regulations Have Induced An Adaptation In Some Fish Species
Our oceans are changing, and the life within them is adapting to those changes (and to humanity’s presence as a fierce, prolific predator). Decades ago, when fish populations started to become a legitimate concern, regulations were put into place that mandated large mesh nets that would allow smaller fish to not get caught, thus helping to prevent overfishing. Seems reasonable.
But when the hauls continued to decline and they looked into it, they noticed something sort of weird: The fish weren’t growing as fast, and seemed to be reaching sexual maturity more quickly. And while many theories exist as to why this may be, some are looking at something called fisheries-induced evolution.
Soon, they'll be the size of molecules, and we will accidentally breathe them.
Basically, they’re trying to stay small enough to not get caught and have babies early enough to keep the species going. In theory, our attempts to protect the fish populations have actually backfired -- we’re actually making things worse because smaller fish means fewer eggs.
Granted, this isn’t a universally accepted theory, with other factors like climate change coming into play. But it's kind of a mind-blowing idea that our solution was, "Only catch big fish." And fish responded with, "OK, time to stop being big."