Evolution

This was a reflection on evolution that I wrote 15 years ago and posted on my BDN blog. It's the basis for a new blog reflecting on how technology progresses, a kind of evolution itself.

Last year we commemorated the 150th year of the publication of Charles Darwin’s book The Origin of Species, and the 200th year since his birth. Recently it was announced that the first synthetic microorganism had been created.  Given these events it is interesting to speculate on the future of evolution. Indeed, it is possible to ask if natural evolution is approaching an end.

            I can envision a day not far in the future when it will be possible to have two machines on my lab bench. In one machine, a DNA sequencer, I will be able to place a small number of bacterial cells. The instrument will break the cells open, extract the DNA, and then read its sequence. The sequence data will be fed into a computer connected to the internet. A computer program will analyze the sequence and return a list of all the genes in this organism, a blueprint of what it is capable of, and the complete parts list for making a new cell. The 2nd machine, called a DNA synthesizer, has four bottles attached to it. Each bottle contains one of the four chemicals DNA is made of.  The computer will read the sequence of the DNA into this second machine and it will synthesize a new copy of the DNA, essentially making an exact replica of the original DNA of the bacteria I started with. Except, there will an important difference. Using the computer, I will be able to manipulate the DNA sequence that is sent to the synthesis machine. I can change the sequence to modify genes, delete specific genes, or add new genes to the original sequence. Once the 2nd machine has synthesized the new, but altered, DNA sequence it will place it in a small drop of liquid. I can take this drop of liquid and add it to a vial that contains the ingredients necessary to create a new cell. I will have purchased the vial from another company that produces kits for creating new cells, essentially empty cells that do not contain DNA. Once the DNA is in the new cell, it is a living organism, and I can grow it in the lab; replicating it millions of times. The new cells will become whatever the original cell was that I started with. Except, for an important difference. Based on how I have changed the original DNA sequence, the new cell may lack some capability of the original, it may be faster or slower at carrying out some function, or it may be able to do something the original cell could not. The entire process of producing a new cell will have taken one day, or less. In one sense, I will have evolved a new cell; by continually synthesizing and modifying the original DNA with a host of different modifications I may be able to create an entirely new species.   What I have described is not currently possible, neither the machines or the laboratory kits exist.  However, based on scientific and technical breakthroughs in the last couple of years there are no compelling reasons to think this will not be possible. So far as we know, there are no fundamental rules of physics, chemistry, or biology that stand in the way.  Of course, the devils are always in the details, and at the molecular level the complexity of biology is so far beyond our current comprehension that the details may conspire to make this impossible, or limit its practical application to a very limited number of organisms.

            As a scientist focused on answering a set of questions about the little bit of the world that I am expert in, I find this kind of technology amazing. For example, the bacteria I am trying to understand in the laboratory are difficult to grow, and many conventional techniques cannot be used to study them. This is actually true of the majority of bacteria that carry out important processes in nature. Supposing such a technique as described above works, then for the first time I would be able to study important cellular mechanisms in detail. For example, I could test to see if a certain gene has a function I am interested in. Or from a practical point, I could add new genes to the cell that would add to its ability to remove pollutants from water.

            But what does this say about evolution? Could this scenario represent a new world where humans can design new life and new species almost at will? Will synthetic evolution inspired by humans outcompete the processes of natural selection that shape our living world? What would Charles Darwin think of all this?

            Darwin’s brilliance was to recognize a fundamental truth about how the biological world adapts to a changing environment. Remarkably, he was able to visualize the pattern of how species evolve into new species. He had the discipline (and time) to logically think this through, and write it down, along with the intelligence to recognize many concrete examples illustrating how it works. What is most amazing, he did all this nearly fifty years before the discovery of how inheritance works, which is the modern science of genetics. Genetics explain’s the mechanisms of evolution and allows us to conceive of synthetic organisms. 

            Perhaps this is an answer, the synthetic evolution experiment described above might be altering the mechanism of evolution, but not the overall pattern. As such human-derived synthetic evolution is another manifestation of natural evolution. I suspect if Darwin were alive today, he would be amazed by all we have learned in 150 years, but recognize there is still much about the intricacies, complexity, and connectedness of evolution that we do not understand. We may tinker with it in a sense of wonder, and to explore these unknowns, but we best do it wisely, for peril and calamity are quite possible outcomes of doing it wrong. Synthetic evolution is still evolution and ultimately will proceed according to the dictates of natural evolution.

While we tend to see ourselves outside the realm of evolution, we are not. We are a manifestation of natural evolution and whatever we choose to do, or not do, with our remarkable technological prowess will ultimately be subject to the dictates of natural evolution as Darwin understood it. The wisdom of choosing to do this, and how we go about it are fascinating questions in themselves and the grist for future columns.