Sganesh,
Most of what you say is reasonable in various lights, but not much of it can be answered with simple yeses and noes. Let’s have a go at some of it.
Firstly, what is randomness and what does it have to do with Darwinism? That one has been chewed loudly to rags, both here and elsewhere. Views have ranged from variations on “Nothing is random” to “Everything is random”, with a lot of variations in between. Unfortunately, being in between is no guarantee of being right or even helpful. In this matter relevance is crucial. Although I have been repeating specifically that randomness is a function of how hard it is (how much information is required) to describe an effect, or alternatively, how unconfidently one can predict an outcome, one seldom can justify day-to-day evolutionary events on such principles.
Another problem is to put a finger on what constitutes a distinguishable evolutionary event. I have referred to “silent” genetic changes, such as recessive mutations that might not show up for generations after the first genetic accident <ahem!> that created the first of the line. Someone else (correctly) pointed out that many such mutations simply died out. Now, most such mutations are very hard to characterise; we used to think automatically of a genetic change as a DNA base change, or insertion, or deletion causing a change in the protein that a gene encoded. The more we study the matter however, the more options we find for how actively a protein or control string of nucleic acid is produced, and in combination with what other products and under what circumstances, and more things than I can think of offhand.
Then again, suppose we do in fact have a genetic change, what will its effect be? Physiologically important? Visibly phenotypically important? Speciationally important? Those things are not necessarily the same, please note.
Some recent work has strongly suggested that most speciation events are based on single, highly random genetic events, which makes it all look very simple, except that all such a speciation event usually would do is to render two sub-populations effectively non-interbreeding (reproductively isolated, as they say). The daughter populations still have to undergo the adaptive selection that will establish them respectively as viable independent populations, by processes that need not at all be equally arbitrary and abrupt. And those processes need not be any less “random” in their advent, though they could be far from random in their effect on the evolution (in any sense) of the population. And of course, if the populations compete, one might well drive the other to extinction. As a rule, if both populations survive it is because they have diverged into different ecological niches or parapatric distributions.
Now, evolution aside, and as a matter of logical principle, how can randomly adventitious events, as a general principle, lead to highly non-random processes? Surely and obviously, anything of the kind must be about as likely as closed-system decreases in entropy? As monkeys typing Hamlet?
Not so, but far otherwise! Let’s consider examples, hopefully illustrative.
Suppose I were to persuade you to invest in a lot of assorted tablets of water paints. I then talk you into applying water and a brush at random and stirring things up. What do we get? You know very well: maximised entropy, embodied in a muddy brown, indistinguishable, non-representational mess. To be sure, the result is not in all ways random; with remarkable consistency we always get much the same colour, non-random though such a consistent result may seem. But Mona Lisa shows there none, and nothing like any thrilling picture. Yes?
Well, next I talk you into buying a cement mixer (Using your money, I am too stingy for either experiment!) You set it up and I charge it with a barrow-load of stones and perhaps some water. I ask you to predict what we will get apart from a lot of noise. “Some grit I suppose,” you reply.
And you are right as usual. Mind you, when we stop the motor after a few hours of the neighbours complaining about the racket, we notice that the jagged stones, though still nothing for Henry Moore to brag of, do seem to have become less jagged... Now, how could that be? We could hardly have assaulted their peripheries more randomly, could we?
Now, let’s abandon these tedious scientific speculations and experimentations in favour of some sparkling reminiscences from my own life, exactly the sort of thing you have been hoping for.
When I was a little boy (my parents were honest but poor and all that sort of thing) I once spent a summer holiday at a not-yet-popular coastal village called Gansbaai. (You know Gansbaai? No? Oh…) Well anyway, it had a lot of sand and sandstone shingle. It still has them.
Except that in those days it among the rest of its shingle, it used to have a LOT of white sandstone rocks, remarkably smooth and strikingly precisely ellipsoidal (each of the mutually perpendicular planes of symmetry representing a different ellipse!) Nowadays the place is far more popular and you no longer find such stones without weeks of search. All wasted in the souvenir boxes of trippers.
Wasn’t that entertaining? Didn’t it bring sentimental tears to your eyes? No? Oh...
Well, then try this one:
In the local, largely sandstone-topped mountains, many streams, some seasonal, others perennial, run down and gouge great gorges out of the rock. There is a high incidence of minor waterfalls, and commonly there are potholes under the falls. The potholes are as a rule strikingly round and surprisingly deep, and many of them contained (mostly stolen by now) stone marbles typically some ten to twenty cm in diameter, and *beautifully* spherical.
“Now justasec JR!” I hear you cry, “what kind of fool do you take me for? You planted those rocks there, right? Bias is all very well, but perfect, smooth ellipsoids? And in special cases, spheres in cylindrical, smooth-sided holes? Pull the other one!”
Nope. I insist. Here we have an instance of a *constrained random process*. Such processes are of the most fundamental importance in all sorts of situations in nature. My pet rocks are just one class of myriads. *They are exposed to a pretty well random influence*, but by their very nature only their external surfaces are exposed to abrasion and spallation. What is more, their most distal and gracile parts are most violently assaulted. It is in fact a particular class of natural selection. (The fundamental way in which it differs from Darwinian selection, I leave as an exercise for the advanced student.)
Notice that although there are all sorts of unpredictable (“random”, right?) *aspects* to the process, the upshot is highly, though by no means perfectly *predictable*, very far indeed from substantially random. No paintpot-brown here!
Hmmm... unless you count paintpot-brown as a "strange attractor" logically analogous to such trends as for abraded stones to become rounded. Tricky things, these constrained random processes!
OK, have I laboured the point enough? Constrained randomness is perfectly possible, even omnipresent, and can lead to drastically non-random results without the slightest hint of intelligent design or conscious intention. It does not follow that intelligent agents cannot employ such principles or influence them; in suitable contexts that is called “technology”. For example, tumbled stones are common in cheap jewellery, right? Fundamentally the same principle as in the potholes.
Now, how far must I draw analogies between the constrained selection of the stones in tumbled abrasion and of strains of living creatures in adaptive selection? Only certain, suitable, stones gave spectacular results under certain circumstances. Only certain, suitable, genotypes, via their phenotypes yield high levels of viable adaptations under suitable, largely destructive, selection. Swap the selection for two genotypes, and you might get different outcomes, even extinction.
Deeply varied types and degrees of randomness give drastically different or eerily similar evolutionary upshots. I visited Australia some years ago , and I was repeatedly stunned by the degree to which just a few genera of plants produced large ranges of functional adaptations, and conversely, how practically unrelated genera produced practically indistinguishable results, not always independently! (Figure it out!) If you happen to go there, (especially the south and west coastal areas and outbacks, pay especial attention to Grevillia, Acacia, Banksia, Hakea, and a few more, particularly in their knee-high, arid-scrub incarnations. Amazing!) In South Africa there are many more examples, but because of the greater biodiversity, the effect is less striking, though it frequently makes a real fool of one! Especially the xerophytes.
Again, what one might call the micro-events in the evolutionary process are as random as one could make them, and teleology is not even on the horizon, but though the course of adaptation is not generally predictable except in minor degrees and contexts (Remember Orgel’s “second” law) there is no way one could rationally look at the course or outcome of the process and call it random.
Now, various people spoke of the mental processes or intentions (or lack thereof) in the participants in these processes. However, generally there was nothing like consciousness involved of course, or when there was, there was nothing like teleology. Not in natural selection anyway.
As soon as teleological artificial selection takes a hand, adaptation, though short-term, speeds up by orders of magnitude. We have bred no talking dogs or flying pigs, but what we do have has come about practically overnight, in thousands or even tens of years instead of hundreds of thousands or millions. (actually, there are counter examples, but never mind those for now. They are generally instances of concentrated selection focussed on particular adaptive requirements. )
More interestingly, we ourselves as a species are on the brink of an opportunity that has not occurred on this planet before. If only we could get our fingers out and our brains and goodwill into gear, we could be the first species in this neck of the galaxy to apply planned, conscious adaptation to its own evolution.
Try *that* one on for shivers on a hot day.
OK, I know that is not what you asked, but was it helpful?
Go well,
Jon
