Chernobyl and Evolutionary Change
It was early in the 1960s and my family had recently relocated from Nebraska to the Los Angeles Basin. Those were scary times! The Soviets were threatening to install nuclear missiles in Cuba, and President Kennedy had decided to stand up to them with all he had to stand up with. The end result was the thirteen-day Cuban missile crisis of October 1962. While I was barely eleven years old, I remember the confrontation all too well.
What I remember most was my mother’s anxiety, and her fundamental need to do whatever she could to safeguard her husband and children in the face of the certain death surely coming for us.
As a newly-minted professor in the California university system, pops didn’t make enough money to allow us to build a bomb shelter, so mom was forced to devise a plan to protect us with what we already had – in this case, a narrow hallway in our tract house in Orange County; a scant two miles from Disneyland (not to mention several other primary targets).
While her efforts were almost certainly futile in the long run, what she put together at least made her feel better about our chances to survive a near-miss. Unless we were blessed a direct hit, her plan would most likely have bought us a couple days or maybe even a week or two before we slowly succumbed to dehydration, starvation, or radiation sickness.
A perfect plan? Probably not, but at least it made her feel like she was doing all she could. Like all sons, to this day I still love my mother, and am grateful for all she did for me and my sister and my dad… but possibly most of all for herself. We all have to be who and what we are, even when our words and deeds don’t make any sense.
I actually have a reason for this distressing stumble down memory lane, so please bear with me.
Last weekend marked the 40th anniversary of the Chernobyl disaster in Ukraine. It was a massive explosion at an outdated and obsolete nuclear power plant that filled much of eastern Europe with radioactivity, and refocused all of our thoughts on nuclear annihilation yet again. I also remember this all too well.
There has actually been quite a lot of press about this anniversary, and there’s no reason for me to delve into all of the various articles and published horror stories — you can look them up on your own time if interested.
One which did get my attention, however, was on the BBC website with the catchy title “Surviving in a poisoned land: Chernobyl’s wildlife is different, but not in the ways you might think.” This well-written and comprehensive study —would you expect anything less from the BBC? — talks about the lifeforms that have managed to survive in what should be a radioactive desert.
It is a most impressive article, and I encourage you to read it, and any of the others that touched on this anniversary. For now, let’s start with their admittedly brief summary of the big-picture ramifications of the explosion and radiation release:
Four decades have now past [sic] since Chernobyl’s reactor number four exploded on 26 April 1986, sending radioactive material far and wide. Winds eventually carried radioactive dust as far as the UK, Norway and even parts of North Africa. But the landscape immediately surrounding the power plant in northern Ukraine received the heaviest dose. Intense radioactive hotspots still persist today.
What got to me, however, and prompts this specific post, is how life has somehow found a way to exist within this atomic wasteland.
Another quote from the BBC may help illustrate their findings:
Many feared the effect of such radioactive contamination would be devastating for the animals and plants living nearby. Almost all the humans in the surrounding area immediately left. These creatures could not. During the 40 years since the disaster, it has become clear that many species are living quite happily within the 37-mile-wide (60km) exclusion zone set up around the ruined power plant. But that’s not to say nature hasn’t changed here – sometimes for the worse.
For years, researchers have documented weird, twisted trees, swallows troubled by tumours and even an eerie black fungus that lives inside the radioactive ruins of the reactor building itself. Some creatures might have adapted to better cope with the contamination – but this idea is notoriously difficult to prove and still hotly debated. Recently, researchers have highlighted other reasons why some animals may have flourished in this injured landscape.
The article invests a whole herd of nouns and verbs discussing this, and I am certainly not prepared to pass judgement on their observations or interpretations. It is safe to assume, however, that some of us hold to the premise that any losses or changes at the species level are inherently bad, while others cling to the somewhat sunnier interpretation that the modifications are nature’s way of adapting to changing environmental conditions. They would likely remind us that genetic change is actually a good thing, because it’s how nature has always responded to these types of environmental misdemeanors.
While the debate continues to rage with those who are on the scene, I can’t help but lean towards the side which credits nature with doing what it has always done best: rolling with the punches and adapting to the earth’s continuously changing biosphere. (Indeed, much of Marker Bed — my recently published novel now available on Amazon — clings to this as one of its overarching themes.)
In Jurassic Park, Ian Malcolm tells us that “life finds a way.” What a powerful concept! There are oodles and scads of examples of this, with many, many more to come as humanity continues to stress the planet, leading to the inevitable environmental depredations that are affecting its natural surface.
I’d like to offer two examples to help validate Dr. Malcom’s simplification of one of the earth’s fundamental biologic imperatives — one from these days of modern times, with the second from a couple billion years ago that built on itself — layer upon layer — for over eight hundred million years.
Let’s start with the one happening today, and which is likely in part our responsibility: bleached coral. Yes, it sounds terrible and awful and we all think it’s something to be avoided (as long as it doesn’t interfere with our economy), and it surely is! But the reality is that not all coral species are affected by this, and the ones that aren’t will be the ones that survive to continue the coral lifestyle into the future — a perfect example of Darwin’s theory of natural selection in action.
Sorry to disappoint the doomsayers, but coral reefs have been on earth for over five hundred million years, and some version will likely still be here long after we are gone. Is this good? Is it bad? That’s up to all of us to decide for ourselves, but either way, it’s reality!
The second relates to “banded iron formations” – the largest iron ore deposits in the world. I will do my best to craft a post dedicated just to this topic — it’s fascinating how a study of BIFs can help us understand the evolution of earth’s oceans and atmosphere, as well as the appearance and evolution of complex lifeforms — but to get us past now, I’ll just give the short version.
Two billion years ago, the biosphere was basically composed of cyanobacteria, which lived in the surface waters of earth’s oceans. In many ways they were just like us: they needed to eat and poop. Both tasks were simplicity itself: for food they took carbon dioxide directly from the seawater, and expelled oxygen back into the water as their waste product.
“Well, shit!” we would have said if we’d been alive at the time. Free oxygen is toxic to almost everything, as we learned in an earlier post titled “Paleontology: How the Earth Makes a Fossil”. But… having free oxygen available is great for the conversion of glucose (sugar) into energy.
(It’s all about metabolism and energy efficiency: no available free oxygen, and a primitive cell can get but 57 kilocalories of energy out of each mole of sugars it consumes. Called “anaerobic fermentation,” this is what yeast still does to cause bread to rise, and make beer — two of life’s critical staples so we’ll choose to like fermentation, even if it is terribly inefficient. But oxygen metabolism jumps the energy production to a whopping 637 kcal/mole — much more efficient to be sure, even without the beer!)
Anyway, two billion years ago our atmosphere was predominantly carbon dioxide (as were the gasses dissolved in seawater), with very little oxygen. But the bacteria kept spewing this incredibly toxic oxygen into the water, and then into the atmosphere; fundamentally altering the earth’s water and atmosphere by removing the carbon dioxide and replacing it with free oxygen.
How rude!
This completely changed the reality of our planet, and killed off much of what was living at the time. But it also paved the way for oxygen metabolism, and, ultimately us.
Anyone want to complain about that?
Didn’t think so, but even if you do, I think we can all agree that all evolutionary changes — be they physical or biological — aren’t necessarily bad.
