Nature’s “perfect balance” is a mystery scientists are trying to decode

So here's a shocking fact

In the Pacific Northwest, the trees need salmon. What? The trees need salmon

Do you want me to unpack this a little bit as how I got to that aha? So something that's generally true about nature, including our bodies, is that everything is regulated

And what I mean by regulated, it means that in our bodies, there's all sorts of substances

Some that are in very small amounts, some that are sort of medium amounts, some that are in large amounts

And that those levels, those amounts are kept in check by some of the body systems, by all sorts of regulatory systems

Some of that is feedback regulation. And that's important because sometimes if we have too much of one thing, that's a disease

too little of something, that's also a disease. So for scientists to figure out the rules of

regulation in the body, to know what the right level of insulin is or what the right level of

red blood cells are, that's been really important to managing health and managing all sorts of

situations. So what's true for the body is also true in broader nature. It turns out there's rules

in nature that govern the relative abundance of plants and animals And when we understand those rules we know better how to manage those places for sustainability for their health and our health

While society's been humming along and enjoying all these advances in agriculture and medicine

in the last 50 or 60 years, ecologists have learned a lot about how nature works

I've codified these into a set of rules called the Serengeti rules. I call them the Serengeti rules because you can see them in operation in the magnificent Serengeti

You can see them in operation in all sorts of other places like Lake Erie, but I don't think Lake Erie rules would have sold as many books

So a couple of those rules that are really important is that some animals are more important than others

meaning they have an outsized impact on the communities in which they live. There's sort of poetry about nature

of every creature has its place and its purpose and everything is equally important

That's not true. The functioning of these ecosystems are sometimes much more dependent upon certain individual

species or small groups of species than others. That's really important knowledge because if we lose those species, those communities

can collapse. And if those communities are somehow compromised, reintroduction or boosting those species can

have great knock-on effects on the overall health of the ecosystem. So, for example, in Yellowstone National Park in the United States, it's a pretty

famous story of reintroduction of wolves which had been exterminated from the lower 48 and the last wolf was killed in Yellowstone in about 1924 So there have been no wolves for 70 years in Yellowstone

And you might say, so what? We can get along without these large predators. Well, that's been shattered by ecological discoveries. These large predators play a

really important role. In the case of Yellowstone, essentially, trees need wolves. Think about that

for a second. Trees need wolves. How do you draw that connection in your head? Well, it's by wolves

controlling the browsing and grazing of deer and elk. That was absent for 70 years. It was stunting

plant and tree life in Yellowstone. And so wolves were reintroduced in 1995. And within a decade

you could see changes in the landscape of Yellowstone. And those changes led to

increased abundance of other sorts of creatures. Similarly, we know that some species have really strong indirect effects on others

So for example, in the Pacific Northwest, the trees need salmon. Rivers don't have a lot of nutrients

A lot of the nutrients in those rivers comes in from the ocean in the form of salmon bodies

And when those salmon are taken by all sorts of carnivores, and when those carcasses are left on the stream banks

the nutrients from those carcasses fertilize the trees. and we can actually trace those nutrients from the ocean into the trees in the Pacific Northwest Who would have thought of such things As we learned about all sorts of hidden connections and ecosystems we realizing

first of all, why were some of our actions so damaging? But flip side of that coin is why a

little bit of action now can be so rewarding, can be so positive, and that these systems

these sort of webs of life can be re-stitched just by the introduction of certain key creatures

This is really important because we are nature's manager now, whether you like it or not

we've taken it over. We're trying to manage nature for the long run so that we have the

things that we need and hopefully nature can persist. So we need to keep exploring

these interactions, whether they're interactions within the body or they're interactions out there

in nature to manage our future. You see the payoffs in medicine, every discovery, every new

medicine, the way we manage so many diseases. That's entirely the fruit of the last 50 years

of understanding these basic rules. We need that same sort of mindset to be taken outdoors into

nature so that we can manage the planet better. If we managed our bodies the way we managed the

planet, there would be a revolution. Want to dive deeper

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