As if this year hasn’t been disturbing enough, now comes the science reports that we share 50 percent of our DNA with bananas. And yes, you read that right. I did not mean to say bonobos, with whom we share 99 percent of our DNA. And I certainly did not mean to say my Uncle Ted, a genetic throwback who can make a banana look like college material. Apparently we’re all a little bananas here.
If these reports are true, and if my understanding of genetics isn’t any worse than Uncle Ted’s, I would say that this means that we are as much like a banana as not. I do have to wonder if this could help explain why many of us bruise so easily, never seem to fully ripen, or are simply rotten through and through. As these reports could have some significant consequences in how we view our friends, family, and the definition of cannibalism, I think it deserves a closer look.
In the interests of full disclosure, I must say at the outset that I am not a genetic scientist, and wouldn’t even recognize one if I saw one. And though I may have been called a banana once or twice, it has never been proven. The fact that many more people call me a nut should also have no bearing on my findings. So let’s pull back the peel of your average banana and see if we can figure out what the scientists are talking about.
Scientists say that to understand the commonality between bananas and humans, you have to put Uncle Ted out of your mind and go all the way back to LUCA, the Last Universal Common Ancestor of all life on earth. This common ancestor was a single-celled bacterium that lived 4 billion years ago, when bananas and humans weren’t even a gleam in its genes. That, fortunately, did not stop those genes from mutating, evolving, and creating ever more complex life forms, like plants, animals, fungi, and Uncle Ted, who I’m pretty sure would be classified as a sponge. But not all of them. Half of those genes were involved in the basic cell processes that support life, like making energy and repairing damage, and so continued as they were right through to today, unfortunately missing out on all the accolades the other genes got by creating bananas and humans. In football terms, they’re the offensive line that supports your team’s advance downfield. Without a good one they’d still be playing in the primordial slime.
OK, so we share half of our genes with bananas. I’m alright with that now that I understand it’s not the thinking half, at least for most of us. One doesn’t have to listen to some people for too long to make you wonder if their genes aren’t really playing for Team Bananas. Team Scientist, on the other hand, is never satisfied until they’ve challenged that thinking half, in ways that can make the average person only feel like a banana. Genes, they remind us, are not DNA, and in fact make up only 2 percent of the stuff. So what team, you ask, after checking for bruises, is 98 percent of our DNA playing for then?
Well it turns out that 8 percent of it is more like the officials, regulating the game by switching genes on and off, while the remainder is all the litter left behind by fans disappointed in the outcome of the game. It’s what’s known as “junk DNA,” and has no known function beyond confusing the genetic scientists. What all this basically means, beyond the relief I feel about not becoming a genetic scientist, is that it is half of our relevant DNA, not our total DNA, that is shared with bananas. A little more worrying, perhaps, I wonder if it also doesn’t mean that every team is made largely out of stuff that rightly belongs in the trash heap. Humans, anyway, seem pretty anxious to make this a reality.
In 2003, the Human Genome Project finally succeeded in determining the DNA sequence of the entire human genome, essentially the blueprint for constructing a human being. Up till then, blueprints were not available, with the predictable results that construction went awry from time to time. Since then, funding issues and bureaucratic meddling have stalled the expected improvements.
After their 2003 triumph, worried genetic scientists went on to figure out the genomes of other living things, like bananas, to see how closely we’re all related. It might be interesting to know then that humans share 25% of their DNA with daffodils, 60% with fruit flies, 70% with slugs, and 80% with cows. If you would like to pause at this point to compare the physical and behavioral characteristics of people you know, that’s perfectly understandable. Cats beat out dogs 90% to 84%, but cat people have not been prone to gloat, possibly because they’re generally asleep 95% of the time. And a casual glance around the planet should be enough to demonstrate that we share 98% of our DNA with pigs.
It’s all enough to make me think that genetic testing companies like Ancestor.com should quit monkeying around and give us the full picture of our family trees. Bananas and all.