Is Evolution Really Random or Do We Have Some Control Over It?

[sylas]

I had been thinking of doing this anyway, sganesh88, so here goes.

I think i need to specify clearly what i mean by "random" and how i conclude evolution is, according to that definition, random. Ofcourse when a bear falls from a mountain, its initial downward acceleration is 9.8m/s/s.-> not random. In the group of fruitflies you mentioned, those with wings survive(no fan scenario)-> not random.

I don't quite get where you are going here. You provide examples, but not a definition.

But look at the origin of all these. This touches upon the concept of freewill and let me be clear that i DON'T support creationism(I hope that will make you read the whole post without sarcasm)

Can an organism by itself "decide" the outcome of events and work towards it? . When an organism X confronts a situation (Like the casino situation you mentioned), its history helps it in dealing with it. Courtesy:Genes. If i am a good mathematician, I can easily calculate mentally and have a better chance of winning the game--> Not random in a superficial way. But what made me a good mathematician? Was that consciously decided by me independent of my past history? or was the decision to pursue math deterministic?

I don't know why we are talking about free will here.

Let's go to a hypothetical scenario. Two groups-> Predator X and prey Y. In the Prey group Y, all the members individually get affected by the predator group X. Some random mutation occurs in one particular individual of the Y group leading to the formation of rudimentary eye that helped it escape from X. It then went far, mated with other Ys. A group of Ys with eyes became commonplace after several generations because other Ys were eaten away by Xs.
This is what we call Natural selection. But think about other unfortunate individuals of the Y group. Does this mean they have simply no role in the encounter with X group? They couldn't have done anything. They went down without any conscious fight. Meaning that their fate isn't in their "hands".

I get the point, but the particular example is dubious. You can't form an eye from a random mutation. The formation of an eye requires a whole pile of mutations, and time for them to arise and be fixed in a population. It's a favourite example for creationists, who mistakenly think there can be no selective advantage to these mutations until you have an eye in place. But let's not side track into evolution of the eye, which is well discussed in a number of places.

A more plausible example would be mutations which made the prey species a little bit closer in color to the sandy sea floor on which they live, or a little bit more different. When a predator moves into grab a meal they are a bit more likely to end up eating a prey individual that is seen more easily. Over time, the mutations that become fixed in the population are more likely to be those that help make the prey closer in color to the sea floor.

Under these conditions, the tendency to the coloration might seem inevitable. That's not necessarily the case, however. There are other strategies that might have been hit upon; such as developing a propensity to feed amongst the darker seaweed, or burrow in the sand.

About the only certainty is that there will be evolution.

Analogous to this, Evolution says that the determination of greats like Gandhi,Einstein and Abe Lincoln are just random(random according to this definition) because they were just groups of cells acting in unison and the genes instructing them to behave in such a way in such a situation(not random in a superficial way). There was never a conscious fight. If there seemed to be one, it was just an illusion. Am i right in understanding Evolution in this perspective?

It is not even clear that the determination of "greats" has anything particularly genetic, nor that it gave any reproductive advantage. I don't think evolution says much about this, and we've got the whole question of nurture vs nature showing up.

Ghandi had four children, and a fair number of grandchildren; but not exceptionally so. He was in many ways a lousy parent.

Einstein had three children, one of whom gave him grandchildren.

Lincoln has no surviving descendants at all; the last died in 1985.

It seems to me that you have mixed up a personal and humanist view of greatness with a biologial and evolutionary view of fitness.

-----

There's another thing I have been meaning to add into this thread. It's a common presumption that evolution leads to "better" and "better" organisms, in some sense. This can be misleading.

Living creatures are already well suited to their normal environment. The major competition they have is with others in their own species.

Frequently, the changing characteristics within a population is a crucial part of the environment for determining fitness. An animal which lives quite nicely thank you at one time might not fare so well if suddenly transported to live with its own descendants a hundred thousand years hence, even if the environment is otherwise identical. It would likely be outcompeted. But, ironically, the individual a hundred thousand years hence suddenly restored to its ancestors might also fare less well, in that it has been moved out of the milieu for which it was adapted.

A very common feature of evolutionary change is related to sexual selection; natural selection in the way of winning a mate. To this end, many creature evolve bizarre structures and forms. Impossibly overweight antlers. Flashy plumage or enormous gaudy tails. A bright red rump. And so on. And perhaps also a large brain fits in here as well. The idea is seriously proposed and there's no reason to reject it on evolutionary grounds. It's a hypothesis to be tested, and it can be tested indirectly; correlating sperm competition with brain size in primates.

Precisely what features end up being selected in this way can depend on accidents of mating preference and this MIGHT actually be something "chosen" for a creature with the capacity to think and reflect on the matter, if we acknowledge such a thing as free will. That's partly why I think the free will thing is a distraction that misses the real points at issue here.

Cheers -- sylas

 

[zomgwtf]

Ah sylas, when I had mentioned it would be 'ineivitable' I meant only under the specific conditions which were available. Including the fact that the ability to have larger brains was still present.

This is the same thing for you color changing prey. The ability for the prey to be a closer colour to the waters floor combined with the fact that this will give it a greater probability to live to reproduce will make it ineivitable that this colour will become more prevelant in this organism. OR that it will further evolve it's colour in subsequent generations but the original change in colour will still have occured.

I agree with everything you have written thus far except that you consider evolution random. Evolution isn't random (by chance) it is something that just occurs naturally.

The way that I see this situation is that if we went back to a specific evolutionary event, say one allele dominating in the population. If we went back to the time period which this allele was existing and the conditions were exactly the same then it would again become dominant in the population, given that all conditions were the same. If it were random or based on chance however, it may turn out the same way or it may occur differently. Depending on what chance it has for either situation, this is not evolution.

I do not think that fact that I have evolved say a smaller jaw size is in any way based on chance. Even though it could have occurred differently the prevalent conditions at the time allowed for it to occur. Even if the conditions are random that doesn't make evolution itself random either.

Am I wrong in my thinking here? This is what I have learned of evolution in the past few years. From various sources, including talkorigins which you mentioned sylas.

 

[Jon Richfield]

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

 

[zomgwtf]

Jon I must say reading what you wrote was quite intriguing. I think you and I have pretty much the same view of Evolution and I'm not so sure why I felt that it was any different before.

One thing I like to add though is that regardless of what we see as the evolutionary outcome of any event does not effect how random the act of evolution is. As you illustrate it could occur any other number of ways which us humans in most cases would not be able to predict. Evolution would still occur though and it would not be random, it is something that just happens and generally speaking over an entire population over time it leads to better adaption to the current situation.

 

[Jon Richfield]

Thanks zomgwtf, that was a nice thing to say. As for misleading impressions that I may give concerning my opinions, sorry about that. I am not a quick thinker and consequently I produce lousy first drafts. This is a tricky subject, both scientifically and philosophically, as many dilettantes discover to their cost :-)
Frankly, I have long given up feeling guilty when an observation concerning Darwinistic processes and products make a fool of me, and I get the impression that most professional evolutionists of any experience are equally philosophical about such things.

Cheers,

Jon