Alan Stahler: Diversity equals survival

Bumblebee with a yellow face on an iris makes a mess – covers itself with pollen – as it is their job.
Photo by Nancy Gilbert

Imagine you are an animal growing up in a world where almost every other animal … wants to eat you. A shell covers your body. The harder the shell, the more likely you are to survive.

No matter how much you wish your clam was tougher, there is nothing you can do about it – you stick with the clam you were born with. Fortunately for the draw, some of your neighbors have inherited genes for harder clams, which makes them better protected.

With all these hungry mouths, those of us with tougher shells are more likely to survive … and pass those hardshell genes on to future generations. By choosing – choosing – which individuals survive, the hungry mouths put selective pressure on the population and urge them to develop harder shells.

However, hungry-mouthed creatures are not blind to what their dinner is doing. Her mouth also continues to develop. Those with harder teeth … or teeth that work like saws or drills … will eat more. They too feel selection pressure: over the years, predators develop a better bite.

The evolution of two species – each reacting to the other – is co-evolution. In coevolution, however, no species need to work against each other. Species can develop together through cooperation. The close collaboration between flowers and bees has grown out of millions of years of such collaboration.

Plants are good at pulling water out of the soil … not so good at pulling nutrients out of the tiny rock particles in the soil.

Mushrooms, on the other hand, are good at drawing nutrients from rocks. They chemically attack the rock, break it down, pull out minerals and atoms. In contrast to plants, however, mushrooms cannot produce their own food.

Like living cobwebs, fungi grow around and in the roots of plants and supply the plants with minerals and atoms.

Plants harness the energy of sunlight and use these nutrients to make food … not just to feed themselves. Plants send the fungi a healthy piece of the food they produce through their roots.

Mushrooms feed plants … plants feed mushrooms … plants feed us.

If it just could be that easy.

We’re in the kitchen cooking a meal … only to find that an important ingredient is missing. A quick look at the grocery store should solve this problem. But to get this ingredient onto the grocery shelf it had to be transported from a warehouse … previously processed in a factory … grown on a farm (shipped through the Suez Canal?) … all possible steps to get it into our food.

You and I are newcomers to this planet. With “you and me” I address not only my readers … but all people … all members of the animal kingdom … and the plant kingdom … and the mushroom kingdom …

Life on earth developed almost four billion years ago. There were no animals, plants, or fungi for the first two billion years. Life consisted entirely of two groups of organisms, both of which were unicellular: bacteria and archaea (“are-KEY-uh” … which look simple) like bacteria, but live very differently. For example, some archaea live in hot springs, in water that is far too hot for bacteria to survive.)

When animals, plants and fungi developed after about two billion years, the bacteria and archaea welcomed us … as new habitats. From the beginning they moved into our intestines, onto our skin and into the soil and lived on. Much of what “we” do to keep ourselves alive – a lot of chemistry, the trade in atoms – is done for us by our microbiome. Sterile mice that are kept bacteria-free in the laboratory die quickly.

So it is in the ground. Attempts to simplify the soil ecosystem – for example by growing just one culture over large areas – risk the same fate as sterile laboratory mice.

There is a lesson in the history of life: diversity creates resilience. Charlie Brown summarized: “I need all the friends I can get.”

Al Stahler enjoys sharing science and nature with friends and neighbors on The Union and on KVMR-FM. He teaches for both children and adults and can be reached at [email protected]