Shaping the Environment

Before looking at a more radical example whereby symbiogenesis with bacteria played a key role in the evolution of a certain metazoan lineage, I thought it a good idea to stress the significance of the terraformers.

The common perception of bacteria is that they are primitive, single-celled organisms. Yet they are not primitive; they are extremely sophisticated in many ways. That’s something most readers of this blog can probably agree with. But I would also argue that, on balance, it is also misleading to think of bacteria as single-celled organisms when, in reality, they are more like cells that are part of superorganism. They form a web of connections. We’ll explore that in future blog entries.

But for now, consider another common perception of bacteria – they are minor players and easy to ignore except when they cause disease. Wrong. Our existence is built on the back of bacteria. Consider a recent survey of the ocean’s biotic diversity:

marine microbes account for up to 90% of all ocean biomass and collectively weigh the equivalent of 240 billion African elephants.

240 billion African elephants. And it’s safe to say that the majority of this microbial biomass is bacterial. Consider this from “Prokaryotes: The unseen majority” by William B. Whitman, David C. Coleman, and William J. Wiebe:

Thus, the total amount of prokaryotic carbon is 60–100% of the estimated total carbon in plants, and inclusion of prokaryotic carbon in global models will almost double estimates of the amount of carbon stored in living organisms. In addition, the earth’s prokaryotes contain 85–130 Pg of N and 9–14 Pg of P, or about 10-fold more of these nutrients than do plants, and represent the largest pool of these nutrients in living organisms.

In fact, how many bacterial cells exist on the planet? Answer – 5 x 10^30

And as any microbiologist will tell you, these cells are found everywhere we find life, including places where bacteria are the only life forms.

So why is all this significant?

With conventional thinking about evolution, the environment is the designer-mimic, culling the genetic variability of the population to create the best fit. But what is “the environment?” If bacteria are effectively omnipresent, due to their sheer mass and distribution, then the environment always includes bacteria. And since bacteria influence their environment, the environment has a distinct biotic component meaning the designer-mimic itself is at least partly biotic. After all, can you think of one evolutionary transition that was not in some way, directly or indirectly, indebted to bacteria?

And if (what an if!) such life forms exist because of design, the designer-mimic exists because of design. The abiotic “environment” has not been designing life for billions of years; life has been designing other life for billions of years

And all of this ties into another front-loading expectation: .

Evolution would be significantly driven by intrinsic, biotic features. Since the design itself would be biotic, then the more that evolution is likened to a biological process, the more that design can be connected to such evolution. In other words, if evolution was purely a function of random happenstance propagated only because such events happened to elicit greater fitness against the backdrop of haphazard environmental conditions, we would predict that the ability to design the future through the present would be quickly be swamped by noise. But if there is a strong, intrinsic component to evolution, the designs are buffered against such noise.

If bacteria are shaping and controlling the environment, then the “the backdrop of haphazard environmental conditions” is greatly dampened. Evolution has been occurring in a controlled setting.

For those who have read TDM, you know I have raised the specter of artificial selectors embedded within cells – carefully chosen components and architecture that function to nudge life toward preconceived objectives. Now we add another dimension to the picture – bacteria functioning in a manner that controls factors outside the cell and nudges from this dimension. Another puzzle piece appears to fall into place.

Might there be a way to connect these two levels of control?

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3 responses to “Shaping the Environment

  1. Fascinating. I always wondered if you would ever get into this aspect – the ‘terraforming’, the idea that “the environment” was itself shaped to get particular results. As ever, I wasn’t disappointed.

  2. Average weight of adult African elephant: 4.6 tons.

  3. As even PZ Myers said yesterday evening, “My precious animalia — they’re inconceivable without bringing bacteria into the picture.”

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