The way most human beings form their thoughts are based on sensory input: the eyes, the ears, the nose, taste and touch; these senses report information to the mind. In this chapter, despite brief digressions, I will describe the eye–the evolving window–and the way it allows us to form our image of the world. I will attempt to detail, among other things, the various ways that animals, with different faculties, have adapted to their environments…
I’ll start with something that is widely known, though I feel I should include it: there is a particular species of dolphin with eyes atop their head. They live in turbid water and ‘see’ by echolocation. This is a unique sensory input, denied to most humans, but flourishes in bats, the platypus, and other monotremes…
Echolocation has been known to develop in human beings to compensate for blindness. I am reminded of watching a video of a blind young man riding a bicycle, playing basketball, and being able to describe the way he mapped out objects. He emitted tiny clicks as he walked and, when they reverberated, appeared as a three dimensional green image inside his head. It lacked subtle definition, but he could play ball and, amazingly, could play video games, of which he was very fond. Likewise, bats see by projecting high pitch sound waves that vibrate in such a manner that works like sonar imaging, as used on submarines. There is another, special case, the star nose mole. It ‘sees’ with it’s nose, mapping three dimensional structures by measuring the closeness and distance of faint and robust smells. To human acuity, we rely most deeply upon our eyes. When we lose our sight, the other sensory organs become refined.
It is not always enough to be favored in your genetic makeup; human beings are most adept at meeting most of nature’s challenges. Since no genetic information is changed mid-life, adaptation throughout life is a type of natural selection, but a conscious one. There is a lot of evolutionary baggage, however, that we, as a species, carry around. Our prefrontal lobe is too small; our adrenal glands too big; and our awe is usually misled by ‘faery fancy’ as Richard Dawkins called it in his extremely provocative book Unweaving the Rainbow. Science represents the way in which we strive to understand a world of amazing complexity and beauty. A Christian ethologist, would, perhaps, have a greater sense of humility toward nature and our natural heritage. This field of research leads, inexorably, to the abandonment of the insipid idiom ‘intelligent design.’ But to listen to the televangelists, one sees the sales pitch of the used car dealer, lip service to a dead doctrine fleecing money from the gullible and dying.
Science doesn’t sell its information. It is available and observable and for the entire world. It is not a religion to say one is humbly awed at the mechanisms of life. It is through this process that theories live and die. How could one look at Moses’s burning bush and then look at the Helix Nebula and be more impressed by the shrubs? The Hubble Deep Field, a portrait of thousands, and thousands of galaxy is so staggeringly beautiful, it is hard to see the aversion to these discoveries and their understanding.
As for Dr. Dawkins, to whom this book is dedicated, he changed the way I looked at the natural world–reading The Extended Phenotype was somewhat of a revelation. It changed the way I viewed the behavior of different organisms and, in the by lines, the behavior of human beings, especially those repulsed by their natural heritage. I hope to settle this issue presently.
Galileo was imprisoned for the heresy (fact) of a Heliocentric Solar System; he was so imprisoned because, not for the information he was spreading, but for the egos he was wounding. It was not in accordance with a tribal book cobbled together by nomads who wandered through the deserts of Judea two thousand years ago. Galileo’s eyes were wrong.
It was a wound to pride; to think oneself to be the reason for all creation, at the center of the universe, and made in the image of God–all of these are real conceits. When the theory of evolution (I say theory out of habit; it is scientific orthodoxy and, at this point, indisputable) came about, the ego was again affronted.
To deny the great white males their place on the pulpit, to suggest we evolved from more brutish, less intelligent ancestors, couldn’t be true. It was an affront to the ego of man and that is at the core of the issue. To a man, having descended from Australopithecus, (the famous Lucy comes to mind) a creature on the cusp ‘tween man and ape, down through the generations having given spark to daughter fires: a. forensis, Africanus, the Cro-Magnon, and the Neanderthal. There are no gaps. It was a gradual gradation.
To me, the religious wonder is misplaced: to see that we are all children of the Earth, connected and having grown and diverged one among another; I think this is a grand and beautiful account of life, much more so than a ‘let there be light’ refrain. The true story of light and how it behaves will play a prominent part of the later segments of this book. To continue the apologist mode of ‘this meant that’ is, in this day and age, untenable. It can’t be both. Religiosos (from the Latin batshit crazy) pick and choose what they will allow to science, to allow what science says. If carbon dating confirmed that Jesus lived, I guarantee you they would have no issue with the ‘inability to date fossils.’ It is an offense to that which made us human to begin with.
To question, to seek answers, to ask why, to find meaning, that is human nature. Having meaning and answers given to you, from someone who says they are infallible, is missing out on a richer, broader perspective of the natural world–it is the self denial of humanity. And the pious themselves, though having benefited greatly from the minds of scientists, denounce that which affronts their delusions of importance. To trace the variety of life since the constitution of the eukaryotic cell takes you through millions of years: through the Cambrian (where many of the first phyla and fossils and eyes are found) into the Permian (and it’s great extinction) through the Carboniferous to the Cretaceous (another mass extinction) and find that, through it all, the will, the very drive of life, the force that still permeates us, the same eyes we share with long dead animals, our noses and our mouths, our diets, we are living the same way.
We are all children of the Earth, no species no more special than the other, and to equate intelligence with superiority is a crude method of approximating self worth. Competence is not inherited. Not by race, not by species, not by man. Evolution shapes and molds the natural world in a way that allows for organisms to be tuned. It is not the way around; nature found the statue under the block of marble in shaping us.
Throughout evolutionary history, along with our barbaric tendencies (one need only think of the genocide, slavery, infanticide, and wholesale slaughters of women and children in the old testament to see this–and this is where apologists say we should derive our morals) we have evolved a finer nature: a nature less accusatory and suspicious, less covetous and more serene, more appreciative of the world, and deeply interested in what science allows us to understand.
Like the other animals, we care for our children. We teach them how to learn and feed them. For my money, teaching a child how to learn on their own would be a most gracious favor, as there could be no bias. We follow the herds for food, we depend on the fruits of the trees. The world is truly our mother; having made us does she plant the fruits that we may live and bring more of our kind. We are another step in a very long slideshow of life and, having made it to where we are, I think constitutes more of a miracle than any parting of the seas.
This is a grand view of life, a sprawling tree with many fruits, and there is, to me, more wonder and awe before the laws of nature than for the obscurantist morality tales of primitive people. The common argument against evolution is not an argument against evolution. We did not evolve from monkeys. Evidence shows we are much further along than the old world monkeys (and the new world monkeys) but, if you were to go backwards in evolutionary time, you would encounter our common ancestor with our closest animal relative: the chimpanzee. One volume alone, compared to the massive genome, divides us from these animals.
I sometimes find myself thinking of a particular parrot; it was mentioned by Douglas Adams a few days before his heart attack (We miss you Douglas; you showed us how to laugh and love) and it was a story of a particular type of parrot living in isolation. He goes into convergent evolution briefly (something we will come to later) and tells a charming story of one of his favorite animals.
The animal was a flightless bird, a peekapoo, with really small wings, but it had still not evolved the understanding that it long ago abandoned flight because there were no natural predators. It was easy to eat more and more and fly less and less and they, over many generations, became flightless. What I found most endearing about his story, and its poignancy in human evolution, is the strange way the animal mimicked long dead evolutionary change. Despite not being able to fly, these birds, so determined, often climbed up trees and jumped off. They fly exactly like bricks don’t, as Douglas Adams once said.
There are evolutionary stable strategies that once were efficient and, because of some ecological change or displacement, rendered them inefficient. They will gradually be tuned by nature, blindly they will be selected. This same argument can be made of man.
We ascribe petty feelings to the Gods; jealousy, a demand to be worshiped; a demand for us to constantly beg; the vanity of such a being is detestable. I don’t see how, seeing the myriad of problems in the world (famine, disease, genocide, murder, the suffering of innocent children, etc) this being, if it were actually there, one should not through pomp ceremony celebrate his love; they should collude against him before he wipes out life again. The crime of religion is the uncanny fortification they instill in their children. They teach them to believe a book of uncertain origin over the tests and proofs of a million or more scientists of our modern times and instead rely on a book whose authorship can not be attributed whose construction is cobbled together and contradictory and, of course, there’s no need for proof of that. Somebody you never heard of is telling you how you should live your life (which most of the Bible does not) and, the opponents of evolution who demand its proof, demand no proof of their own creed. They don’t need proof that it’s a book of uncertain authorship. The most brilliant minds of our generation have explained things once in the realm of religion. And those who didn’t agree, whose opinions were different on some of the subtleties of thought, they weren’t burned at the stake; imprisoned; or tortured. The debates were settled with reason, logic, and experimental truth.
I use the term to describe a pejorative levied at me when writing for our journal in my senior year at high school. The paper was a call for people to stop worrying about what created the world, if there was an afterlife, and just be kind to human beings, and make the most of the only life we’re sure we’ll ever have. In the American South–this is tantamount to blasphemy. Being an atheist has, throughout my life, meant the end of relationships and friendships. I was once forced to leave a man’s house for writing with my left hand. I don’t know what the cosmic bogeyman has against lefties, or pigs, but there has to be a point when logic kicks in and you go, ‘Why do we believe these things said to have happened thousands of years ago, when we surely wouldn’t believe them if they were reported today?’
Why do modern people still, in the face of insuperable odds, still favor their delusions over what they can see with their own eyes? We see stars dying and coming together every day. Does this mean that God didn’t create all the stars in one day or decided to get up after the 7th day and make more stars? I think this has survived from the days where people believed that, if they didn’t dance for the rain or sacrifice a human being on an altar, the Gods would be unappeased and the sun wouldn’t come up.
These tendencies are still with our species. They just have more elegant forms. One would imagine a Mayan, perhaps an Einstein of their people, daring to wonder if the sun would return anyway, that it obeyed fundamental laws, and it didn’t require the still beating heart of a slaughtered man to do its job.
Today it is an amalgamation of superstition and statistics. I’m sure that many naturalists, myself included, have a lucky shirt, or a lucky tie. My brother has a special type of superstition when it comes to college football. If he wakes up and his team is winning, he goes back to sleep. If he wakes up and they’re losing, he watches the game. If his team wins the game, it reinforces the statistical likelihood matched to superstitions of this kind.
I’d like to introduce an animal parallel. In experiments done at Kings College, a particular type of flightless pigeon was placed into a box. Every time it pressed against a button, a small portion of food would come out. So after days of having lived under this condition the bird is certain that to press the button will bring food. However, the experiment has changed to deliver, at random, the food once brought by the button.
The way this pigeon coped with this has particular significance to psychiatrists studying ritualistic behavior. The pigeons developed certain eccentricities once they realized that the fruit was being dispensed at random. Some of them even developed rituals, rituals based on what they were doing the last time they were fed. Some would tuck their head under their wing and wobble their head back and forth, presumably it had worked, at one point, to bring them food. This type of experiment has shown that animals adapt superstitions in cases where there is no other explanation, beyond statistics and probability. This has been seen in man, also.
If knowledge begins in understanding how little you know, where does knowledge go–what is the price of this endowment? Knowledge is a bitten apple, and we so endowed, are, from the start, limited. It has been speculated that there is, ultimately, a limit as to what a person can know. The Uncertainty Principle is one such theory. I’ll give you an example.
We see a limited portion of the color spectrum, for instance, and do not see a flower in the manner that a humble bee is able. They can see into the ultraviolet and this we humans are incapable of doing without technology. Nor are we able to see into the infrared. There are pitches of sound which our ears are incapable of perceiving. Faculties in possession by other animals, as in sound waves, are heard only by whales and elephants.
Flowers rely on bees for pollination and, it has been said, without bees, if bees were to go extinct that is, the human race would join them in extinction four years later. Seeing the world in their peculiar manner, they are guided to the flower’s nectar. Without bees to pollinate the flowers, the flowers would not be able to derive energy from the sun, and would be incapable of photosynthesis. Photosynthesis is the process where by plants convert sunrays (photons) into breathable oxygen. Look at it this way, if not for bees, we could not survive as a species. This is a testament to the beauty of the interconnected species of this world.
Another fact about the way we perceive the world lies in the finite speed of light. Because light travels at a finite speed, it takes time for it to reach your eye. It might be less than a Planck second, but it is still a moment in the past. How did eyes evolve? Which animal was the first to see the stars? I shall endeavor to answer some of these questions.
A creature, in the early oceans, capable of seeing, was surely more likely to either catch prey or escape from being it. There are periods in evolution called arms races; it is this process by which each animal adapts based upon the higher functioning of the other animal.
The best way to explain this is by illustrating the speed of the cheetah, one of the many delights of the animal world. The cheetah, before its present form, was part of the family Canidae; to begin with, it probably didn’t rush out of the gates at 60 miles per hour. However, by slow gradation, the prey became faster and faster, as only the fastest of the prey were being able to survive to reproductive age. This in turn influenced the evolution of speed in the cheetah. The cheetahs incapable of catching the fastest of the prey died out, allowing for the ever faster cheetahs to out propagate their slower relatives.
The evolution of the eye has been a heavily debated study since the publication of perhaps the most profound scientific work ever published by a human being, On the Origin of Species by Charles Darwin. As Darwin himself wrote, ‘…that the evolution of the eye by natural selection at first glance seemed “absurd in the highest possible degree”. However, he went on to explain that despite the difficulty in imagining it, it was perfectly feasible:
‘…if numerous gradations from a perfect and complex eye to one very imperfect and simple, each grade being useful to its possessor, can be shown to exist; if further, the eye does vary ever so slightly, and the variations be inherited, which is certainly the case; and if any variation or modification in the organ be ever useful to an animal under changing conditions of life, then the difficulty of believing that a perfect and complex eye could be formed by natural selection, though insuperable by our imagination, can hardly be considered real.’
Today scientists have come up with explanations through which the first eye-like structure, a light-sensitive pigmented spot on the skin, could have gone through changes and complexities to form the human eye. Complex eyes appear to have first evolved within a few million years, in the rapid burst of evolution known as the Cambrian explosion. There is no evidence of eyes before the Cambrian, but a wide range of diversity is evident in the Middle Cambrian Burgess shale.
If you take a look at different morphology of eyes and photoreceptor cell types observed in various animals, this would give us an impression that animal eyes evolved multiple times independently. Interestingly ,the entire animal kingdom is dependent on function of the pax6 gene (a sort of master control gene) for the development of eyes and not only this, but the genes that interact with the pax6 gene to form the photoreceptor cells are also highly conserved in evolution providing strong evidence supporting one time evolution of animal eyes but modified on many occasion to suit the requirements of the organisms that bear it. Therefore, as it was previously thought that eyes formed independently many different times, we now know that each type of eye is nothing but a variation on a common theme evolved from a common, simple precursor called which could be called “the proto-eye.”
The proto-eye can be reconstructed by the structural and molecular comparison of extant eyes such as the insect compound eye, the vertebrate camera eye, and the simple pigment-cup eyes found in many invertebrate groups. Its common to believe that all animals do have eyes but a significant part of animal species lack eyes completely or have rudimentary looking eyes in the form of spots e.g.,: Sea urchins, Sponges, Ctenophores, flatworms etc. Eye spots in simple animals spots can sense whether it’s night or day or whether a shadow is passing closely, but fail to form any kind of image like the ones of jelly fishes and bilaterians.
The animal group that exhibit true eyes are a ensemble of multicellular organisms including jellyfish, arthropods, molluscs, annelid worms, onychophora (velvet worms), and chordates. This list is rather strange (if one look at the phylogeny tree) giving us an impression that eyes appeared in scattered lineages and mixed up with groups that lack them. This was one reason of the hypothesis that animal eyes evolved multiple times but this is not true as we have seen earlier.
One of the important aspect of natural selection is that it favors an organism which has slight advantage over others on the planet, which tends to survive and produce offspring for the next generation. According to many scientists from the field, the simple light-sensitive spot on the skin of some ancestral creature gave it some tiny survival advantage, which afforded it the ability to better evade predators and further subsequent changes by natural selection. This led to changes then created a depression in the light-sensitive patch, a deepening pit that made vision a little sharper. Later, the pit’s opening gradually narrowed, so light entered through a small aperture, like a pinhole camera. every little change counts, where the light-sensitive spot evolved into a retina and the magnificence of the human eye today.
For us the eye has been a window to the world. This has psychological ramifications. A child, having a familial bond with his / her mother, can be calmed by the sight of its mother. The child can be appeased when the lights are on, though unsure with the lights off and scared. The child reacts favorably to warmth and companionship. This inheritance, presumably, dates back to the Great Leap Forward (which we shall come to.)
From a psychological view, this childhood behavior can be explained by evolutionary inheritance: it can be understood by the way in which our ancestors lived. Think about the parrot, whose ability to fly has been stilted (though still they try) and the way this could relate to the issues of a developing child.
Today they may be irrational fears, like our dopey parrot, but the fear of the dark, for our ancestors, was a matter of life and death, real fear; a period of anxiety in the east African steppe.
The warmth of the mother could be seen as the calming influence of a group of ancestors round a fire, their happiness with their clan and mother have all been passed to us.
The eyes recoil from a darkness left as an evolutionary imprint on our psyche. One must remember the movie Jaws and, it is famously known, that the shark was scarier before one saw it. In this sense, this beautiful organ, homologous and present in many animals, from reptiles to mammals, attenuates our understanding of what first brought humans face to face with a world not yet understood. They had their senses, their eyes, and their brains. However, there is more than one type of life on Earth.