Fernando Salazar

My last post talked about contrasting evolutionary strategies of large populations that reproduce and mutate rapidly, vs. small populations that use individual adaptability to contend with environmental challenges.  Then this morning in the Times I saw this article: Study Finds Virus to be Fast Learner on Infecting.

The article showed how bacteriophages (viruses that attack bacteria) mutate to use new attack pathways in a matter of days – 15 days in this experiment.  The new attack requires 4 specific mutations, and in 22 out of 96 repeated experimental runs, the persistent little ‘phages hit upon the same set of 4.

Amazing stuff, this is evolution running in the lab.  It also shows the infinite-monkeys principle at work, though in this case the simians aren’t typing Shakespeare, they’re typing a set of 4 mutations.

It’s also a good point to reflect on the fact that we complex, adaptable, novel-writing, sushi-making humans are not the real “rulers” of the planet.  Based on biomass that lofty perch belongs to bacteria, algae and those diligent viruses.

I like reading many kinds of science books, but as a category books on evolution are my favorites.  I suppose it’s because evolution is the great scientific truth that is most discernable.  Certainly, relativity and quantum mechanics are biggies in the truth department, but I don’t call those “discernable”.  Evolution, on the other hand, is all around – just look at a snail or a tree or a bird and ask yourself, “How did that thing get that way?”  Pastafarians, of course, have their own explanation – evolution is mine.

Evolution and the Emergent Self, by Raymond L. Neubauer, takes on the “how did that thing get that way?” question from an intriguing viewpoint, by looking at how complexity arises in evolution.  The starting point of the book is the observation that for all living things there are two fundamental strategies: A maximum growth rate strategy, where the organism multiplies as fast as possible, relying on very large population sizes to mutate and adapt as required; and then a stable or homeostasis strategy, where the organism relies on complexity to provide individual adaptability to contend with changing conditions.  An example would be, in an environment of frequently drying ponds, algae must evolve a special cell-wall to keep from desiccating when conditions turn arid, but a frog can just hop to a different pond.  No organism relies entirely on one strategy over another, but clearly bacteria, shrimp and most insects are examples in the large-population camp, while birds, mammals and good ‘ol Homo sapiens are in the homeostasis camp.

What I found enjoyable in this book is how far Neuberger was able to go with this simple idea, and how many separate destinations he achieved.  An early chapter looks at the information content of life.  Genes and brains both are information storage, in that both are ways of encoding different states.  Having a lot of genes is one form of complexity; its benefit is when you need to adapt, you have a lot of options, in terms of things to turn on or off or to mutate.  Turns out that rice has nearly 58,000 separate protein-encoding genes, while we humans have a mere 22,300.  Reduced to information processing terms, there are about 832 million bits of data in those 22,300 genes.  That’s just over 100 megabytes, about 10 times the size of a program like Microsoft Word.

The human brain encodes a lot more data – with 86 billion neurons, and each neuron with about 1,000 synapses per neuron on average, that’s 86 trillion bits.  That is one long program.  Anyway, having a brain let’s the organism encode a lot more adaptive states than having a lot of genes.

I said this book went to a lot of destinations.  Some others: Why big brains generate the need for play; Entropy in evolution; Sociobiology; and even the origin of life and its likelihood outside our solar system.  All this topical variety makes the book a bit disjointed, but for my part I liked it – it was like a fact-filled but rambling conversation with a congenial genius.

To wrap up, I’d never suggest Evolution and the Emergent Self as a starting point for your evolution-library – there’s The Selfish Gene, The Mismeasure of Man, and countless others to get first.  But if you are looking for something refreshing in the field, pick up Neuberger’s book – I think reading it proves its own point, that having a brain is a good thing.