{"id":26981,"date":"2009-08-27T11:04:29","date_gmt":"2009-08-27T11:04:29","guid":{"rendered":"http:\/\/scienceblogs.com\/gregladen\/2009\/08\/27\/falsehood-nature-maintains-bal\/"},"modified":"2009-08-27T11:04:29","modified_gmt":"2009-08-27T11:04:29","slug":"falsehood-nature-maintains-bal","status":"publish","type":"post","link":"https:\/\/gregladen.com\/blog\/2009\/08\/27\/falsehood-nature-maintains-bal\/","title":{"rendered":"Falsehood: Nature maintains balance."},"content":{"rendered":"

\"i-0f02e0ecbb2389b980d86eebee748143-The_Balance_of_Nature-thumb-500x580-18213.jpg\"<\/a><\/a><\/p>\n

There is a lot of evidence that nature is in balance. An invasive species throws off the balance of nature in a given region by out-competing some similar indigenous form. When something destructive happens there is a return to status quo, eventually. A few cold years are followed by a few warm years, or a few dry years are followed by a few wet years. So, why is “Nature maintains a balance” a falsehood?
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\nRemember what makes a statement a falsehood (refer back to our earlier discussions on this issue). By now you realize that some falsehoods are better than others. “How can a falsehood ever be good?” you may ask. Well, a good falsehood is one that provides an excellent basis for discussion of something interesting. “Nature maintains a balance” is a good falsehood because it opens up more than one can of worms. Let’s just hope that these worms are not invasive species.<\/p>\n

The first problem with the statement under consideration is the word “maintains.” Nature might be<\/em> in balance. The examples I give in the paragraph above, if true, could be evidence of nature being in some kind of balance. Fine (for now). But the belief, under which many people labor, that nature maintains<\/em> a balance is a bit different than nature being in<\/em> balance. Nature maintains nothing. Why do I say that nature maintains nothing? You might think because I don’t think nature has a consciousness or can in any way be assigned intentionality. Perhaps I’m saying that nature does not react like many people think it does to good or bad things that happen to it. And if you thought all of these things you’d be partly correct.<\/p>\n

But there is a more fundamental reason that I gag when I hear the two words “Nature maintains” … Because there is no such thing as Nature. Well, there is sort of, kind of like there is such a thing as “nouns” or “substance” or “action” or “stuff.” But a statement like “Nature maintains a balance” … this causality wielding construction … assigns the property of sentience or even mere coherence to this thing that we call “nature.” But in realith, what is nature? Perhaps everything that is not dark matter? Including dark matter?<\/p>\n

So this is a cool falsehood because it lets us dispose of “Mother Nature” and all her incarnations in one fell swoop. I have not proved that Mother Nature does not exist as anything more than a folk image. I’m simply asserting that if you want to suggest that there is a sentient, reacting balancer entity “out there” that YOU need to come to the table with some proof.<\/p>\n

But we are not done with the “Nature maintains a balance” fallacy. The “balance” part of it is also highly questionable. Let’s look at this more closely. What would “balance” look like in nature? Well, we have some examples above with weather. A few years of above average temperature would be balanced by a few years of below average temperature. That feels like a balance to me.<\/p>\n

However, this is not really a balance. What is happening here is that there is a system that has (for reasons we’ll ignore for the moment) an average for some linear value (ambient temperature in this case), and random variation around that average. Experientially, you will observe this value being above or below the average almost every year, and since it is random there will be many years where warmer than average is followed by cooler than average, or visa versa. There will be some years where a couple\/few years one way is followed by a couple\/few years the other way. What you are observing is not balance, but regression towards the mean, a common statistical property of random numbers in series. Add to this a bit of confirmation bias and you have a whole belief system.<\/p>\n

Now, having said that, I also have to say that I totally buy that “nature is in balance” with respect to annual temperature. How can I say that after I just said that it wasn’t? Because I’m comfortable with the idea that there is an average and randomness around the average as being like balance. If there were just random variations in temperature (if temperature truly did the “random walk”) then we could have at some point several years where the temperature goes up and up and up until the lakes boil. But that does not happen. There is a kind of balance in that there is a certain amount of energy from the sun, it is dissipated in various ways, and distributed within the troposphere and the oceans a certain way. This ‘balance’ is what we should really call “homeostasis.” And it isn’t really random … a few years of warm followed by a few years of cool could be the result of regular shifts in the homeostasis such as el nino and la nina, which are very regular oscillations in climate that occur over several years. Then there are ice ages and hypsothermals which are major changes in the climatic properties maintained by homeostasis.<\/p>\n

(I quickly add: I do think both global temperature and local temperature can be understood as a homeostatic system. However, I’m not sure I would pick this as a prime example of homeostasis if I was trying to explain homeostasis to someone.)<\/p>\n

So all of that could be thought of as a complex “balance” in nature. But that is not what people are thinking when they think “Nature maintains a balance.”<\/p>\n

The other area where people think of nature being in balance is in the interaction between species. Predators exist to weed out the sick and injured. Plants exist to feed animals. These balance-like concepts are best addressed under the fallacy “Individuals act for the survival of the species” …. which we will address at another time. But we can briefly address another inter-species ‘balance’ concept now.<\/p>\n

You have probably heard that when an ecosystem is damaged, it “comes back” …. because nature maintains a balance. If you bulldoze several hundred acres of old forest, eventually there will be old forest there again, for instance. At a larger scale, if continental glaciers march across Canada an the northern US and wipe out all the various habitats, then recede, what was there before will eventually grow back.<\/p>\n

Sorry, but no.<\/p>\n

Yes, a forest may grow back, but it does not grow back because there is supposed to be a forest in a particular spot, or because nature somehow causes all the plants to do the right thing to reconstruct the forest habitat. If it grows back it does so because this is the eventual outcome of competition among species of plants, and plant animal interactions, that happen to result in forest growing back. I know of habitats in Africa that were once forest, then the forest was cut by humans, and grasslands spread across where the forest grew. Now these grasslands are in parks and forest is starting to grow back in some of them. But in some cases, a certain kind of grass has taken over, and this grass species seems to be dominant and terminal. This is the species that will exist here until some major disturbance or climate change wipes it out. No forest, just Imperata<\/em> grass, or so it seems.<\/p>\n

When Afrikaner trekkers got tired of English colonial rules against things like owning people left the Cape Colony (within the modern Cape provinces, in South Africa) in the 19th century, some of them ‘trekked’ north across a certain part of Namibia. A line of several dozen covered wagons headed north looking for new pasture land. As they drove, the wheels crushed to death the tiny little plants that lived on the stony floor of this desert and left a distinctive mark.<\/p>\n

Those marks are still visible today. The plants are still dead. It is not entirely clear how the plants got there to begin with. If “nature maintains a balance”, in this case, nature has checked out.<\/p>\n

When ice age glaciers did wipe out the North American flora, a new flora grew back after the ice melted. But although forest tended to come back where forest was before, the dominant species were different each time. We tend to think of North American hardwood forests as dominated by oak and hickory up to a certain latitude, and then maple north of that. Well, other species dominated during the previous interglacial, and before that, other species did as well. The ecological idea of “succession” whereby the same exact sequence of events, with certain pioneer species arriving first, then some other set of species, and finally, a climax flora of specific species at the ‘end’ of the process does not actually happen in nature. That is often what people are thinking when they expect nature to be in balance, but it is not what happens.<\/p>\n

Nature is not in balance. But it nature is very big. Disturbance is a vital force in nature, and the name of the game is change. There is resiliency, there is homeostasis, but mostly, nature appears to maintain a balance at the scale of ecosystems and biomes because nature is so big that despite the fact that she is constantly falling over, she never quite hits bottom.<\/p>\n

More Falsehoods !!!<\/em><\/h3>\n

This post is one of a series on the topic of falsehoods. The following is a list of falsehoods posts in order:<\/p>\n