Sunday, September 06, 2015
Randomness in Evolution by John T. Bonner (Book Review #69 of 2015)
Randomness in Evolution
**I read Andreas Wagner's Arrival, John Tyler Bonner's Randomness in Evolution, and David Deamer's First Life: Discovering the Connections between Stars, Cells, and How Life Began subsequently, so my review is meant to be read relative to the other two as all three overlap in subject matter. (This paragraph appears in all three reviews). I am reading these books after reading several on cosmology.* I wanted to move beyond what cosmologists say (with disagreement) about the formation of the universe to see how it could be compatible with what chemists and biologists say about the beginning of life. Alan Lightman writes in the Accidental Universe that "Science can never know how universe was created," and I find that to be echoed in these books -- science can never know or prove how exactly life began (Deamer states this outright). Exactly what chemicals were available on earth to mix in what quantities to randomly create a reaction between molecules that led bonds to form, information to be transmitted, and growth to begin? All of the hypotheses presented in the books require certain laws of physics and nature to hold but I have not found any who attempts to explain how those laws arose in the first place. Why are these laws what they are? Call this the Paul Davies critique.
Deamer acknowledges that it's possible a creator put those laws into existence, but the other two avoid the subject. None of the three seem to recognize that chance is not a causal force, so time + chance cannot explain anything. Where did light come from and how did it contain information? How did cells know that it contained information and figure out a way to receive and decode it? How do "regulator cells" operate according to these laws? What is consciousness and at what point is life "life" such that it has "value?" All three of the authors reach the same conclusion as the cosmologists above-- we are a random collection of atoms that will one day be scattered, nothing more nothing less. Life has no meaning outside of a debatable definition regarding complex molecular processes, and any sentiment we attach to it is illogical-- there is no soul in science. I do not, therefore, understand how Lightman, Hawking, Richard Dawkins, etc. can argue that scattering people's atoms is "wrong," or where they get ethics. We're not special, only lucky in the sense of randomness.
These three biochemist authors, however, engage in less armchair philosophy than Hawking et al, and (unlike string theorists Hawking and Green) argue that science requires testable hypotheses and that the universe had a beginning. Each of these books have a good look at what actual laboratory research looks like. These are not just men working equations at a desk all day, although there is some of that. They're often out traveling the world in search of mineral samples and in the laboratory mixing chemicals in the search for the genesis of life. My next set of books will be on the scientific understanding of consciousness-- something these books do not address.**
There are essentially two premises in this book:
1. Randomness explains more of the variety of the life we see today than natural selection.
2. The effect of randomness varies depending on the size of the organism-- the larger the organism, the less variety of morphology can be expressed.
As a student of Daniel Kahneman and Nicholas Nassim Taleb, I enjoyed the same critique applied to the evolution of species that these apply to the wizards of wall street-- success is determined more by randomness, but our hindsight bias makes us think we see skill. Bonner argues that randomness is more important than adaptation/natural selection, in which certain traits evolve somehow to give the organism an adaptation it did not previously have. Randomness has to happen before natural selection can happen, "there can be no natural selection without randomness." So randomness is the "skeleton in the closet," that most "naturalists" would rather not think about. But he doesn't "throw Darwin out with the bathwater," these processes work together. "All of evolutionary change is built on a foundation of randomness. It provides the necessary material for natural selection which then does indeed bring forth the order our inner mind so actively craves." Natural selection by itself tends to ask for an intelligent designer because how else would a cell know what information to pass down, or how would "regulator cells" need to know what cells to form next? Bonner immediately discards creationists as fools. But I imagine some of these fools would be quick to point out that chance itself is not a causal force-- time + chance cannot produce something ex nihilo. Something isn't "caused" by chance, and to his credit Bonner is careful not to state it this way.
How do you know if something is an adaptation or randomness? So many times we consider an adaptation to be an adaptation because of hindsight bias when actually it was random mutation that just worked. Our biosphere today is the result of 14 billion years of these compounded mutations. Likewise, the maximum possible size of organisms increase over the millenia. Bonner describes the difference between prokaryotes and eukaryotes, from Nature.com: "In prokaryote cell organization there is a nucleoid containing genomic DNA but it is not surrounded by membranes such as what defines the eukaryote nucleus (Martin & Koonin 2006). Eukaryotes such as fungi, protozoa, plants, and animals, and thus we humans, have cells with complex structure with internal membranes and membrane-bounded organelles."
He discusses morphology and neutralism. He seems to answer the layman's question as to why we don't see more variety of species that have been around for millions of years. Even if morphology changes very little, an organisms biochemistry can change much. Whereas Wagner (Arrival of the Fittest) seems to argue "junk genes" and traits with no purpose are evidence of a previous purpose in an ancient environment, Bonner seems to argue that these were random mutations that did not really make a difference to an organism's survival, so they were not weeded out. Bonner's focus on research are slime molds.
I think one weakness of the book is in the discussion on how organisms evolve from single-cell to multicell. Bonner cites division of labor in developed organisms in nature and relates it back to multicell organisms. Bonner does a good job supporting his hypothesis about how processes differ in small organisms and larger organisms. Size matters just as randomness matters.
I give it 3.5 stars. It definitely earns points for its concise nature, this is the shortest of the three books. It is written a bit more toward the layperson than Andreas Wagner's Arrival. I would like to read counterarguments.