Loss of Faith: A Darwinian Lift

What a piece of work is a man, how noble in reason, how infinite in faculties, in form and moving how express and admirable, in action how like an angel, in apprehension how like a god! the beauty of the world, the paragon of animals.

-          Hamlet, William Shakespeare

Not only man, each species of living organisms, is a breathtaking piece of design, occupying its niche in nature with perfect poise. One cannot but exclaim in awe at the wonderful process that designed this machine. An intelligent designer who created this perfect design seemed inevitable. Charles Robert Darwin busted the myth of a creator with the publication in 1859, of his book, The Origin of Species. Alfred Russel Wallace simultaneously arrived at this marvellous explanation – the theory of Natural Selection.

Millions of species are designed for their habitat in nature, not by an ‘all seeing’ eye of a creator, but by the blind process of Natural Selection. Theory of evolution by natural selection took the wind out of God’s sail. Bereft of its lofty task of creating all life, it was left purposeless in a universe, which now seemed to need it no more.

The stark simplicity of the theory is deceptive. Its powers are immense. It is now believed that Relativity or Quantum Mechanics, may not be the explanation of matter’s properties in a different universe. But, if complex life is found anywhere else in our universe, or evolves in any other universe in future, the only possible mechanism can be the process of Natural Selection. It is the grandest truth in the universe.

In a few words theory can be stated thus: Non-random selection of randomly occurring inheritable traits in living organisms. Natural Selection is blind because it doesn’t have any foresight, only a principle which it follows indiscriminately. But it is not random. It favours only such traits as bestow on the individual an edge over others in survival and reproduction. Such individuals out-reproduce other members of the species not having these traits. Random variation of traits in a species are the product of natural processes: a chance error in copying of DNA during reproduction, spontaneous mutation in the genes. (These mechanisms were not known to Darwin. He arrived at the theory by observing life, experiments at his estate in rural England, and an unparalleled deft reasoning.) Only inheritable traits are selected. Acquired traits, like the hypertrophied biceps of a blacksmith, skills of an artisan – however, useful they may be to the individual – cannot be favoured by Natural Selection.

It beggars credibility, to believe that this simple law can produce the astonishing complexity in the living world: elegance of a galloping horse, fluid movements of a gliding eagle, the proud strut of a bird of paradise displaying its extravagant plumage, and the razor sharp reasoning of a bipedal ape that attempts to uncover the origin of its own intellect. But the evidence for evolution is staggering. It is irrefutable and easily understood. One needs exceptionally single-minded devotion to supernatural, to close their eyes to it.

Religions and cultures across the globe have told simpler creation myths. God of one created the first man from dust and to give him company the first woman from his ribs. According to another, God out of loneliness, split himself into two, creating the first man and the woman. You can't be faulted if you expect more absorbing tales, given millennia to concoct them.

Religion appropriates the product of evolution for its existence. Every organism is finely tuned for its environment, every organ is perfectly assembled for its function. Camels are designed for survival in a desert: large flat feet to walk on sand, ability to go without water for long, thick fur on the top of body to provide shade and thin elsewhere to permit easy heat loss. Eyes are designed to see, lethal canines of carnivores to kill, as are wings to fly. Purposiveness seems to pervade every thread of nature’s fabric. There has to be a creator who designed this terrific scheme of things. It cannot be attributed to chance. The fallacy in this reasoning is to assume that theory of natural selection attributes this complexity to chance. In fact, natural selection is relentlessly driven by purposiveness – only inheritable advantageous traits survive in the race for survival. But the argument of Intelligent Design is a non sequitur for another reason. God capable of creating the marvellously complex organisms has to be more highly complex. Who created God's complexity? Silence.

Though, Darwin had predicted their existence, no fossil was ever discovered in his lifetime. Since then, a number of them have been found, belonging to every period in earth's history, oldest dating back to 3.4 billion years. Age of fossils, confirmed by isotope studies, conforms to the hierarchy of the grouping of animals devised by Carl Linnaeus a century and a half before publication of The Origin of Species. Not a single fossil was ever found to be buried in the rocks that were older than the age of the fossil species. This is one incontrovertible evidence in favour of evolution. Biologist and polymath JBS Haldane was once asked what evidence will destroy his confidence in the theory of evolution. ‘Fossil rabbits in the Precambrian,’ was his oft-quoted reply. Mammals originated about 252 million years back. Precambrian era of earth lasted from earth’s origin to about 541 million years ago.

Vertebrate animals have a segmental body plan, seen best in the head and neck region. Blood vessels and nerves of the segment supply all organs that develop from this segment. Land vertebrates originated from fish. Segments are clearly seen in fish, laid aft to forth. Development of face plays havoc with the segmental organisation. A plethora of tissues originate from each segment. Each has different growth. This jumbles up the segments. Development of neck in animals further muddles the segmental plan. In mammals head moved up while the blood vessels of its segment remained in the chest. Voice box, i.e., larynx, moved up with the head. Its nerve supply, the recurrent laryngeal nerve, got entangled with its blood vessels in chest. As neck elongated in various species recurrent laryngeal nerve’s circuitous route lengthened. In an adult giraffe nerve travels 15 feet before it supplies the larynx. In its downward course it passes within inches of larynx, but supplies it only after coursing around the vessels in the chest. Such colossal waste! 15 feet length when a few inches would have sufficed. Is this evidence of evolution by the blind process of natural selection, when new species evolve from common ancestors retaining the basic body plan of ancestors, accumulating useful variations on the way? Or of an intelligent design, created by the foresight of an omnipotent designer in its laboratory?

Bodies of the animal get fossilised – though, the chance of fossilisation is extremely minute, perhaps less than one in million. Fossils tell us about the physical features of the animal, its habitat, and its adaptations to environment. DNA obtained from fossils indicates not only the age of the fossil, but also relatedness of the extinct species with the living animals. Comparative anatomy and embryology of living species offers clues to their evolution. But mind is not preserved. Brain, the material basis of mind, is almost never fossilised. Except for a couple of arthropod brains and perhaps one of a dinosaur, no fossilised brain has ever been discovered. Mind therefore, was the last attribute of life to come within the purview of evolutionary origin. Darwin firmly believed that human mind evolved through the same process of natural selection as the body. Wallace disagreed with Darwin. He attributed human intellect and morality to a higher intelligence. Darwin was aghast. ‘I hope you have not murdered too completely your own and my child,’ he moaned in anguish in a letter to Wallace.

Behavioural genetics, genetic basis of behaviour, now reveals that our behaviour is influenced by genes. Genes evolve and are the lynchpin of evolution. Hence, animal behaviour has to be rooted in its evolution. Strongest evidence for this comes from study on identical twins. Identical twins, who share all their DNA, and were separated at birth, think and feel alike in adult lives as if they were linked by telepathy. They have similar tastes in music and food, share same opinion on issues like individual liberty and preference for a political party, have similar mathematical ability and behavioural ticks.

Evolutionary biology provides another important clue regarding oneness of mind and body. Ethology, study of animal behaviour, has established that much of instinctive human behaviour has its parallel in animals. Sexual love and sexual jealousy, parental investment in progeny, sibling rivalry, sacrifice of self interest in favour of kins, aggression to win sexual favour, boasting of status among peers, cooperation, violence are the behaviour and emotions seen in animals too, suggesting their evolutionary origins.

Religion’s lame explanation for human behaviour is that God created us in its own image. Why weren’t animals too, who behave like us, created in the same image?

On February 28, 1953, Francis Crick announced in the Eagle pub at Cambridge that he and his colleague, James Watson, had ‘discovered the secret of life.’ That morning the duo had worked out the double helix structure of DNA molecule. DNA indeed is the secret of life. On the molecule of DNA is written the story of every life in a simple language comprising four alphabets and sixty-four three-lettered words. With this meagre equipment nature has created the wonderful world of living organisms: thermophile bacteria thriving in boiling water of hot springs at a temperature of 120⁰C, giant sequoia trees with heights above 100 feet, flying squirrels, the extinct elephant birds of Madagascar, a peacock with its vibrant metre and a half tail, a device only cumbersome for itslef, but one which peahens love.

A system of knowledge or belief that claims the deepest mysteries of life as its exclusive area of investigation must answer the seemingly inscrutable and enigmatic riddles of life– at least appear to endeavour in this direction. A response like, ‘God made the world in six days, and rested on the seventh,’ is not only unfeelingly facetious, it is patently foolish. It reveals the shallow reasoning of theologists and their gross inability to appreciate the widespread marvels of nature.

Study of DNA has enlarged our knowledge of life in unimaginable ways, thus enriching it enormously. Mysteries of life, which seemed unreal and beyond our ken, now look most natural.

One such riddle is the genesis of social cooperation in some insects. In bees, one such insect, only the queen bee of the hive reproduces. Her progeny, the worker bees, all of whom are females, never produce their own eggs. They spend their entire life tending to their sisters that are produced by the queen bee. What propels these worker bees to invest in caring for their siblings rather than produce their own progeny? There is a tendency to eulogise the mysticism of nature when confronted with such wonders. But there is no such need. Biologists W.D. Hamilton, R.L. Trivers, and H. Hare discovered the ingenious route nature took to arrive at the social behaviour of these insects. Insects of the group Hymenoptera, including ants, bees, and wasps, have a very odd system of sex determination. Only queen bee in a hive reproduces. She mates with a drone once in her life and stores the sperms in her body. As she later lays eggs periodically, these are fertilised in her reproductive passage by the sperm. But some eggs are not fertilised. The fertilised eggs develop into females and the unfertilised into males. Males thus, have only one set of genes – unlike most animals who have a pair of each as also a female bee. A little calculation at the back of an envelope will show that a female bee shares 75% of genes with her sister, but only 50% with her own progeny. ^* Thus, it makes biological sense for a female bee, i.e., a worker bee, to forego producing offspring with whom she will share only 50% of her genes. Instead, she becomes a caretaker of her sisters with whom she shares 75% of her genes. (In the realm of nature, individual life has only one motto; To leave behind as many copies of its genes as possible. Dawkins in his seminal work, The Selfish Gene, explains this concept with a breathtaking clarity. In nutshell, his theory states that we are nothing but ‘survival machines’ of our genes, programmed to preserve and propagate our selfish genes – Hen is egg’s way of producing more eggs.)

Plan for the development of an organism is written on its DNA. Each cell, numbering trillions in a multicellular organism, has the complete set of individual’s DNA and thus the complete knowhow to construct the entire body of the organism. In an early embryo, which is only a cluster of few dividing cells, how does a particular group of cells know that they have to develop into a hand, a greater toe, a liver, or a kidney? This baffled biologists till very recent in the past. Two discoveries in Genetics, in the latter half of last century, solved this conundrum. Genetic switches are a group of genes that switch each other on or off. These switches thus control whether effect of a gene is expressed or not, and also the age of the organism when it is expressed. Genes in chromosomes seem to be scattered randomly, with no apparent order. Order is seen only in their expression. Hox genes, first discovered in house fly, Drosophila, are an island of order in this jumble. They specify segmental identity – whether a segment of the developing embryo will develop into head, abdomen, a wing, or the antennae. Hox genes sense the varying chemical gradient in the embryo in specific directions, i.e., top to bottom, head end to the tail. And in turn they switch on the required genes for the particular organ – for liver they only switch on the liver genes, while the genes for kidneys, intestines, etc. are kept in the switch-off mode. Hox genes have been found in every animal. They are almost similar in composition in various species – a housefly or a human – but for minor alterations. Only their number vary. Richard Dawkins called the genome of a species, the ‘genetic book of the dead’. On its genome is written the history of its evolution. Why did an omnipotent creator have to resort to Hox genes and gene switches? Why did it have to hide these details from its progeny for so long? Silence.

Universe does not impinge on our senses with a force as persistent and intense as does life. It is not difficult to parry queries about the origin of universe and the nature of its fabric by assuming them as abstract concepts not of urgent consequence to human condition. But all of us, at one time or other in our lives, perhaps in the moments of unbearable grief or unreckonable ecstasy, wonder how we came to be in this world.

Darwin revealed to mankind this truth. This truth is the essence of life, our raison d’etre. I was beside myself with surprise and rapture, as I caught the first glimpse of this immense knowledge. My understanding of evolution till then was infantile. Man has descended from apes. This to me summarised evolution. I devoured book after book on evolution, genetics, cognitive and evolutionary psychology, human nature, and working of mind. Understanding of natural selection and evolution, when it dawned, dazzled me with its magnificence. It continues to hold me in its thrall. Born of dust, created in the image of God, a clan from its head, another from its soles; I could finally consign these concepts to where they belonged - puerile concoctions of unimaginative minds. I had now truly lost belief.

 

^*A female bee inherits 50% of her genes from her father and these she shares with all her sisters as her mother mates with only one male in her life. Male bee has only one set of genes unlike a female, and these are therefore not halved during production of sperms. All sperms of a male bee therefore have the same genes. Worker bee inherits 50% of her genes from her mother, and since these are halved during the production of ovum, she shares 25% of these genes with her sister, making a whopping 75% shared genes among sisters, unseen in any other living species.