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We humans are in a constant battle against microbes that surround us, such as bacteria and viruses. Evolutionary theory tells us that as we evolved, so did these microbes. We have developed multiple layers of defense against them, such as high fever, a protective skin layer, enzymes that chop microbes into pieces, and finally, our incredibly complex immune system. Even today, with all our technology at our disposal, if some life form overcomes us, it’s not going to be the mighty lion or bear, it’s going to be the lowly microbe. Why? Because these microbes, although extremely simple, have every evolutionary advantage over us.

First, they have astronomical reproductive advantage. In order for selection to occur, some must die — the higher the reproductive rate and casualty rate, the stronger the selection pressure, and the faster evolution progresses (or should we say, the slower it regresses). If an organism exhibits low reproduction rate, then it must have a high survival rate or else suffer extinction. How many children do you plan to have? You need to have two just to maintain your line. I doubt you’ll have even four. But let’s say that over the past, we humans have had an average of ten children per couple, a generation averages 10 years, and population has remained constant. These assumptions all give unrealistic advantage to humans, and yield a low survival rate of 20% on a 10-year cycle, with a mere 8 children per couple sacrificed for the sake of natural selection by dying without heirs. Meanwhile, how do the microbes fare? Bacteria will divide in as little as 20 minutes when not resource-limited, and viruses can multiply by a factor of millions in hours while infecting a host; but let’s say that they merely divide once a day, and let’s say that each time one divides, one of the two daughter cells dies to maintain constant population. That means that in 10 years, 3,650 cells will die, yielding a survival rate of 0.027%. Under those conditions, the microbes are the clear evolutionary winner, because they sacrifice 450 times more victims to the cause of selection. And of course, the actual ratio is much, much higher.

But amazingly, there is yet more. We are absolutely overwhelmed by the sheer number of microbes surrounding us. There are over 100 million bacteria of over 600 species in every milliliter of saliva in your mouth! You have bacteria covering your hands and feet, in your eyes, nose and ears, in every break in your skin and in your bodily orifices. The number of bacteria in the earth’s biosphere is estimated to be one thousand billion billion BILLION. And viruses are thought to outnumber bacteria. This means that we humans cannot concentrate our defense against just one strain of microbe, but must simultaneously be evolving upgraded defenses against a multitude of attackers.

And to make things worse, the information content in the viral or bacterial DNA and RNA is minuscule compared to our behemoth genome. Random mutational modifications must act on an encyclopedia for humans, and a post-it note for viruses. Generating a useful mutation is nearly impossible for the human as compared to the microbes.

And still, that’s not all. The human immune system, while amazingly clever, is a Rube-Goldberg contraption that is so complex and fine-tuned that it simply cannot cope with the deft and flexible microbe’s mutations. Consider the HIV virus, which actually kills us by attacking and disabling the immune system. How many thousands of years would it take us to “evolve” a defense against it? In fact, we are seeing the immune system fall out of tune, causing allergic reactions to common items like grass, pollen, latex, milk and peanuts. It’s all downhill, not uphill.

Finally, one more consideration: microbes, particularly viruses, are exceedingly pernicious, in that they have extraordinarily diverse and resourceful methods of evading our defenses. They can lie dormant for decades, even centuries; they can survive extremes of heat and cold, wetness and dryness, saltiness, acidity, vacuum and high pressure, presence and absence of oxygen; they can be transmitted by air or water, by touch, kiss, intercourse, sneeze, blood exchange or contact with surfaces in public areas; they can lie dormant in the body and periodically activate (for example, once you contract herpes, you have it for life). The stage when viruses are most communicable is often before they exhibit symptoms, which short-circuits our means of developing a defense through evolution, since the cause-effect relationship becomes hidden and at best subtle.

And perhaps the most amazing thing of all… we need these microbes to survive! In our gut, we maintain a colony of essential microbes. They outnumber the cells in our entire body by at least 10-to-1 and are of more than 500 species. Meanwhile, these microbes are mutating, and could at any time turn against us.

The evidence is absolutely overwhelming that we cannot keep up with microbes in an evolutionary foot-race. Yet, here we are. This is conclusive evidence that we did not get here by a process of evolution over long periods of time, since time operates to the advantage of the microbes. Rather, our history is short, we are devolving not evolving, and the microbes would, given enough time, wipe us out.