Evolution and beyond ?

The following is the mail from a physicist expressing his concerns about the widespread acceptance of the evolutionary theory. I was asked by a friend to respond to the same and what followed was a letter attempting to address some of the issues raised here...

The following analogy from physics might help clarify what I am referring to. In the late 1600's when Newton discovered patterns in planetary motion and proposed his laws, everyone thought we had discovered how the universe functions. In fact by the mid 1800's, armed with many physicists had assumed we understood almost everything about the laws governing nature. But they were all shocked in the late 1800's and early 1900's that they had not appreciated a completely new approach to physics described by quantum mechanics where classical mechanics was merely an "effective" approach. Of course quantum effects are rather subtle and Newton's ideas are still valid almost in all daily experiences. So Newton certainly deserves a lot of credit.

In the same way, I feel the theory of evolution of Darwin, could be a very useful first step in our understanding of life. But there may be many surprises on the way! And as scientists we should be ready for it. In my opinion there are already many questions that evolutionary theorists should be asking. Hopefully, they are building more realistic models and testing the theory of evolution rigorously. Trying to poke holes into the theory. would be surprised if they are not!

For example, some of the subtler questions could be related to the quantum mechanical effects that govern the probabilities in the evolutionary mechanism. I have heard that the physics of protein folding is an open problem in biochemistry and I some people believe quantum mechanics is playing an important role there.

Finally, I am sure you will agree that human emotions and feelings are "observed facts". At some point of time we should address them. How do they arise? We cannot just say "these arise from "complex" connections in the human brain"! You can almost explain anything away through the use of word "complexity" these days and you are not allowed to ask any more questions! Why? "Because it is complex"! Sounds very much like religion to me!

Why did evolution create a human brain that is capable of "sacrifice" for the sake of others that by very nature goes against preserving the "gene"? Why did evolution create many human brains that thinks that "sacrifice" for others is an admirable trait in a human being and respect those people rather than "kill" them at first site! These are some questions I wonder about. I hope scientists just dont use "complexity" to explain away these observed facts and shut me up!

The bottom line is that some people become happy with an explanation about the observed phenomena. Others do not. People who accept an explanation easily are always happy. The question always is where do you draw the line? We scientists have developed some bit of arrogance as compared to non-scientists. We think we understand something better. That may be! Unfortunately, we too have to draw the line somewhere else and say, I am happy with the current explanation since I cannot go beyond this. It is too complex!

My response :

Well, I appreciate the sentiments behind the mail and the spirit behind the questions raised but as someone who has been in a closer association with the field, I do think that some of these thoughts are a result of lack of in-depth study of the field.

Let me clarify, while as scientists, it is right to be a little skeptical about any fact till it is completely proven, Darwin's evolutionary theory is pretty much at that stage in biology. However, the questions that you raised are valid and have been the subject of several studies. Our current understanding is progressing and has still not been able to refute the fundamental principles of evolution. However, yes, we still do not have explanations for all such conundrums in biology. The origin of altruism (sacrificing oneself for others) is one such problem, there are others such as the origin of handicap principle (the male peacock has huge tail feathers which completely incapacitate its flight movements - why it would evolve something like this is another problem which has puzzled evolutionary biologists for long), the evolution of consciousness, the evolution of our mental faculties, emotions etc, the origin of antlers in a stag etc etc… there are numerous such examples for which we do not have proper explanations but the hypotheses that are available are all based on the framework of evolution.

However, there is a caveat here. Evolution as is understood today is of a very different form from that which is commonly understood. In fact, a greater understanding of the subject can be obtained from Stephen J Gould's essays.

There are few things that we need to remember when looking at things from an evolutionary perspective -

1. What exists today is a result of a large number of random events operating at different levels (natural cataclysms to random mutations at the gene level)… but the outcome of these random events is shaped by the process of natural selection (as was proposed by Darwin).

2. Also, one must be careful when ascribing an evolutionarily selective benefit to every trait or character we see. Some of these characters may actually be a case of "spandrels" (as was written by SJ Gould in his essay on the Spandrels of San Marco) i.e. they may not have a selective advantage and may just be a by product of the constraints of life and evolution. Like the spandrels which just exist because of the nature of the construction of the building and not because of the purpose they serve, in this case too, a lot of features in biology are not advantageous all the time.

3. Also, some of the features we see in life today are actually natural consequences or by products of certain other constraints and may not in themselves be subject to the forces of natural selection.

4. Addressing some of your questions specifically,

• The origin of altruism has been a subject of scrutiny in several societies, not just the human. It is seen in other insect societies as well. The "kin selection theory" tries to explain this by speculating that sacrificing oneself still could be advantageous in an evolutionary perspective if one tries to save one's closest kins (because your genes still survive… ). In fact, the genetic relatedness between individuals has been seen as a measure of the tendency to give up one's life. Man, however, is the part of a more complex social structure where the social structure is based on cooperation and coexistence. (I speculate that humans lack the physical strength/skills necessary to subsist as solitary creatures and therefore had to resort a more social living where interdependencies are mandatory).

• In fact, the fields of evolutionary psychology and sociobiology have been attempting to address these and other such questions which are of relevance to explaining human social behavior and psychology in the light of evolution.

• The question of peacock feathers, antlers is another intriguing phenomenon - the handicap principle has come up with another hypotheses to explain the same. It is believed that the bearing of such handicaps could indeed be a symbol of greater ability as individuals (males) surviving despite such handicaps (very evidently responsible for the name of theory) are actually perceived as more attractive for their ability to survive despite such handicaps. There are other theories to explain the same and studies are attempting to prove one as against the other.

• The origin of human consciousness, mental faculties, emotions etc are also areas of intense investigation in evolutionary light. One other aspect which needs to be remembered is that, some traits and features are exaptations - i.e structures which arise for a certain purpose but then gradually evolve for a different purpose all together. That is some of these structures may actually be a consequence of some other evolutionary features. The evolution of human consciousness for example is something which is often explained as a natural end product of a highly developed brain with a very "complex" neural network underneath. A lot of our mental faculties also may not have a natural selective advantage - they may be a natural consequence of certain other features for eg, the evolutionary increase in brain size may have as a consequence developed our faculties for language, social structure, arts etc. These areas still remain in the arena of speculation and are branded as "complexities" not with the intention of evading the problem but because they are genuinely not understood. The human brain remains one of the biggest "black boxes" in life sciences and efforts are underway to try and understand the molecular processes underlying the complexities of memory, perception, thought etc etc.

Lastly, while biologists are working at trying to understand life and the underlying complexities, they are all only trying to do it in the light of evolution because honestly there has not been a better alternative for our understanding of the same. However, the definition of evolution has been expanding ever since the term was coined and newer perspectives are being added with each passing year.

I hope I have managed to shed at least some light on the questions that have been raised by you. I do not claim to be an expert but as an occupational hazard, if not anything else, I have been more acquainted with the evolutionary principles. And, as time goes by I only realize that there is a lot more I need to know. Some things make intuitive sense while some are more difficult to understand and appreciate. It only requires deeper study of the views and counter views to arrive at a clearer picture of the complexities of evolution.

I am sure you will find many more questions and answers to many of your already existing questions if you go through the existing literature in the field. References in case you are interested further -

The selfish gene

The essays of Stephen J Gould

The greatest show on earth

The blind watchmaker

The moral animal

Rise and fall of the third Chimpanzee

Finally, I would like to say that I do agree with you when you say that we should not be blind to other possibilities and as scientists be open and skeptical… but, it just necessitates a more open approach where evidence is interpreted unbiased by prejudices. And that holds true for every subject and field not just with evolution and biology.