Archive for April, 2012
“The process is remarkably simple. It requires only that individuals of a species vary genetically in their ability to survive and reproduce in their environment. Given this, natural selection — and evolution — are inevitable.” — Author Jerry A Coyne in “Why Evolution is True”, page 11.
Any book that has the endorsement of both Richard Dawkins and Christopher Hitchens has my interest. But I’d also read references to Jerry A. Coyne’s “Why Evolution is True” in another science book I was reading, so I sought it out.
What a great book! First off, let me say that the title of this book tells you exactly what you will find inside. This is a fine primer on the actual evidence for evolution, along with a solid description of what the theory does and does not say.
The subtitle to this book could easily be “and why Intelligent design if false”.
Upon reflection, it is a sad commentary that a writer and scientist of this caliber has to spend an entire book working to refute a religious claim that continues (and with some real success) to pass itself off as a valid, competing scientific theory on the origins of life on earth. But that is the reality we live with. In the United States, fully 40% of those surveyed believe that God created the earth and all that is in it pretty much according to the account in Genesis. And believers in creationism are vocal in classrooms across this country, forcing the false notion that both “theories” deserve equal treatment.
But, of course, there are not two theories at all: there is one scientific theory (proven to a point to be considered “fact”), and a religious notion with no supporting scientific evidence at all. Those are not propositions deserving of equal treatment. It is akin to (as Richard Dawkins points out in The Greatest Show on Earth — reviewed this blog) a student in a history class claiming that ancient Rome never existed, but was made up by historians for their own purposes.
Read this book and be a soldier for reality. We need all of those that we can get.
There is one, huge, honking reason why we humans have trouble with the idea of evolution, and it is a reason that I think we give scant attention to: it is the fact that we exist. Because we exist and — more importantly — are conscious of our existence, we can’t help but examine ourselves, find ourselves wonderful, and think that somehow our wonderful existence must — on some level at least — have been the point of everything that has come before us. We are the reason for, well, life. “Clearly” we think, “the universe had us in mind from the very start?”
This sounds silly and overblown, but is it really? Don’t we start any consideration of our origins with the premise that we must find a system of “creation” that would clearly lead up to us? In other words, the process of evolution must be as complicated as we see ourselves to be, which, under the influence of our natural solipsism, means there has to be an intelligence behind it all that is at least as clever as we are (but only more so). And suddenly, we have replaced the idea of “life” having had us in mind from the start with the idea of The God of the Universe (who, apparently, had nothing better to do with 13.75 billions years of his eternal existence, and decided to run a grand chemical experiment to see if he could turn mass and energy into living hominins who would, occasionally, tell him how great he was).
This is not, I’m afraid, an understatement of the self-centeredness of our species, nor of the absurdity of the proposition of our own divine creation. The truth is that we can only hold such irrational ideas because we are a natural storytelling (and believing) bunch of hairless apes, and there remains much mutual support for such beliefs among us profoundly-social primates.
But the problem is this: we have built back from the end of the story, assuming that the story began as a tale with us as the ending. Even more fundamentally, we assume there was a story in the first place. There wasn’t. There was (and is, if you want to be absolutely clear about it) only nature.
By nature I mean purely natural forces, and the biological, geologic and meteorological products of those forces. For there wasn’t even “nature” (at least in the sense that we understand it today) 5 billion years ago. Only the cosmic beginnings of what would coalesce into our planet.
Seriously. We now know this.
Our planet formed from dust and debris and matter and gravity and atoms and elements born in other exploding stars (that “made” the stuff our planet is made from). This is how all of the planets and stars were formed — each of them “local” events (when compared to the vastness of the expanding universe). And, after untold millions of years of “forming”, the mix of solid crust, liquid water (and the chemical composition of that water), the fact that we had a solid core to produce a magnetic field to hold our atmosphere in place against the forces of solar winds, and time (lots and lots of time — about a billion years after the earth “formed”), something began to stir. Or maybe not even stir. In the beginning it was simple photosynthetic bacteria that began to occupy the earth.
And for the next 2 billion years that was it. That was the only life on the planet. For 2…billion…years. What kind of creation story is that? What kind of intelligence is behind that? There is the popular (perhaps apocryphal) quote that says “If there is a God, he must be inordinately fond of beetles” (having created hundreds of thousands of species of them). But perhaps we should change that to God being “Really, really fond of simple photosynthetic bacteria”.
Here’s the rundown of the history of the evolution of life on earth as laid out by Jerry A. Coyne in “Why Evolution is True”:
“If the entire course of evolution were compressed into a single year, the earliest bacteria would appear at the end of March, but we wouldn’t see the first human ancestors until 6 a.m. on December 31. The golden age of Greece, about 500 BC, would occur just thirty seconds before midnight.”
Most creationists either do not know the evidence for all of this, or are actively resisting it. I expect more of the latter than the former, for even the ignorance is fed, at some level, by an innate resistance to the notion that we aren’t special in the way we prefer to imagine.
But of course we are special, and by any measurement pretty damn amazing results of a non-random process of selecting random mutations in living, reproducing species. But we have to be clear that this is what happened. All it takes, it turns out, for evolution to occur is the presence of DNA that is exchanged and re-combined through (often sexual) reproduction.
Mutations in DNA happen all the time, all over the genome. But no-one is deciding what mutations will occur. This is truly a random process — there is no predicting when and where it will happen, nor what the result will be. Mutations are often the result of biological “copying errors” (take that, perfection of design). But whatever the cause, those mutations are then expressed in the developing individual, and, once expressed, have entered into the race for survival, living, reproducing, competing and dying on the stage of life where natural selection exerts its unforgiving force on every living thing.
Yet despite what every creationist seems to believe, natural selection is not an intelligence (though it creates an outcome that mimics an intelligence). It is simply describes the process whereby the reality of climate, food supply, competition for resources, competition for mates, and an animal’s innate suitability for a specific niche in the world place that animal under selective pressure. Those that are better at surviving tend to survive and pass on their particular set of mutations. Those that aren’t, don’t. But conditions are always changing, so today’s winner will not always be the winner. Dinosaurs were winners for 160 million years, but then they lost. Big time. Right now, we’re the winners. Right now.
Once you take the time to understand what evolution is, and what it is not, the arguments against it are shown to be what they actually are: nothing. I mean it — there are no valid arguments against evolution. There are only dodges based in fear, ignorance and credulity (because of the things we want to believe about ourselves).
The reality is that there was never any plan or system in place. Everything that we see around us is the eventual balance of forces that tends to come about over time. Earth settled into its shape because of the materials it is made of, which set the levels of gravity where they are. The dominant cosmic lement of carbon became the building block of all biological life. Our bodies took the shape they did because of the mix of air we evolved in, and the gravity that gives us weight. Our eyes evolved to work well in the kind of light we experience, our guts to the kind of food we can eat.
We are constantly taking in nutrients, feeding the bacteria that still makes up half of our cellular weight. We carry in our DNA huge collections of genes that have been switched-off by random mutations (left in the “off” position by the selective pressures of natural selection). In many ways, our complex and inspiring bodies are nothing more than the result of a survival “arms race” (as Dawkins put it) that began with the first bacteria competing for a place in the sun.
And DNA, it turns out, builds up entire bodies by completely local actions. There is no blueprint, but each gene and protein does it’s own little thing and, before long, voila, there is a new living being.
How can this be? It can be because we evolved from the simplest of life forms that gradually grew more complex (even incorporating other organisms, and turning them to our own use). Every step of our evolution was built upon the life form we were before every mutation. Nothing about us ever simply came into being out of “nothing” (that is, ironically, the creationist view of what God is supposed to have done). We did not go to sleep one night as a bacteria and awake the next morning a fish, or dream our fishy dreams to awake as a primitive ape. Evolution posits no such thing. However, the inescapable evidence of our DNA shows the “indelible stamp of our origin” (Darwin’s famous words) — it is a record of the many different animals we were. There is no other plausible explanation for this than that which evolution supplies.
This drives creationists crazy: it simply cannot be — it sounds too improbable and impossible. There has to be a plan.
Why? Who says so? Who can say to reality “You cannot be thus” or “You must be this”? No one has that kind of power. Not you, not me, not the scientist (for this is the implication — that scientists are simply making this stuff up to disprove the God they hate so much). The scientist reports what is true, what is actual, what is declared by the evidence. And the evidence tells us that we evolved from bacteria — every one of us representing that unbroken chain of life back to the very beginning.
As Jerry Coyne puts it in “Why Evolution is True” (reviewed this week): “The process is remarkably simple. It requires only that individuals of a species vary genetically in their ability to survive and reproduce in their environment. Given this, natural selection — and evolution — are inevitable.”
Inevitable, yes. Designed? No.
But how could an entire human body evolve from a single cell? As has been pointed out by another: you did it yourself in nine months.
No wonder Darwin said “There is grandeur in this view of life”. For there is. But in order to find it, we have to first let go of the diminished, narrow, ignorant view of life as having been created by a divine intelligence. Then, and only then, will we see, face to face, the true story of our creation.
This is an outstanding experience. For one thing, Neil deGrasse Tyson is the most impassioned champion for science. He is inspiring. For another, Stephen Colbert turns out to be the best of interviewers. He is funny, yes, but what comes out most is his sincere interest and humanity. And underneath all of the great information is the sight of two smart, interesting people truly enjoying each other and the subjects they discuss. It’s a long video, and the audio is a bit distracting for the first part, but stick with it. You’ll be glad you did!
A friend asked me a question — an interesting thought experiment: If God were to make a 30-second announcement to all of humanity at once, what would he (or she) say?
The future-predicting part of my brain had already prepared a response to what I thought my friend’s question was going to be (if God did such a thing, how would I — as an atheist — feel about it? My answer: pissed). So at first I wasn’t certain I would have a decent answer question he actually asked. But then it came to me.
I thought that God would say to us all: “Every one of you evolved from earlier life forms that were created through completely natural processes. So relax. There are lots of other life forms out there in the universe, but you’ll never meet them. Be nice to each other.”
Today I’m thinking about my two reactions, both to the anticipated question and the actual one. I’ll talk about the “pissed” response first.
Despite what most believers might expect, I wasn’t angry that God existed. As one who puts his confidence in evidence, were there to be actual evidence of the existence of God, I would naturally bow to the obvious. (I’d want to be sure, however, that there was actual, testable evidence, and not merely a mass hallucination!). No — I wouldn’t be angry that God actually existed: I would be angry at God for being such a bastard son of a bitch.
Why? Because if God were to say what I suggested he say to his creation, he would be acknowledging that every shred of evidence that we’ve found on this planet was, in fact, correct (and that you religious fundamentalists could stop beating up on the poor scientists, thank you very much!). That would mean that God was, in truth, a distant commentator (of a deistic sort) who perhaps touched off the big bang and let the rest just happen according to physical laws.
Or perhaps not even that, for the questions inevitably multiply: was God, then, created by those natural forces? Did he design the natural forces themselves? If so, could anything so created really be called a natural force? Which brings us back to the uncomfortable fact that God had turned out to be, essentially, an evil trickster sort of god (with a lower-case “g”).
As soon as one inserts the actions of a supervisory intelligence into nature, you suddenly have to confront the question of intention and, hence, morality and ethics. So, when you bring God to a nature fight, that is when nature becomes cruel, wasteful and just plain mean. Without God, all you have are blind, mindless, unintentional natural forces that do the “picking and choosing” that are the process we call natural selection. And natural selection operates without thought or intention, which means it is also without malice or cruelty. Evolution, because (as a theory) it is essentially a description of the process by which species adapt into more or less successful creatures (through the non-random selection of random mutations — as Richard Dawkins might say it) it does not play favorites the way an individual with a mind would.
Okay. so let’s look at the alternative view (the one that is, essentially, put forth by young earth creationists), that God planted the evidence of evolution (all those pesky fossils) and deep geologic time to test our faith. In essence, he made sure that there was no direct evidence of his existence, and set humanity loose on a life-or-death scavenger hunt for clues that he cleverly decided to hide so deeply that no-one (or, at the least, only a chosen few) would ever find. And that even those sparse clues would be so vague and ambiguous as to be really, really tough to have faith in, even for the most faithful.
That’s the kind of God I could be really, really pissed at. That is the son-of-a-bitch God that would fit the model of the spoiled kid that thinks the servants in his rich parents household are his playthings and not equal human beings.
Am I being unfair to God? No. Not really. And I find that I have accidentally come upon another fundamental problem with the whole idea of God, and it is a paradox.
We believe that God is good, and the source of all that is good (and, therefore, the creator of the universal standard of human morality). We blame the Devil for all of the cruelty and evil in the world (the result of humanity’s famous fall from grace in the Garden of Eden). And so we modern humans are left to struggle upon the earthly venue for the heavenly battle between these two unequal (and yet somehow “allowed” to be nearly equal in this “world”) forces.
The paradox is this: it is the introduction of the idea of God itself that stains all of creation with the stamp of good or evil. It makes a moral problem out of the parasite that hijacks the brain of its victims so that its hatching young can eat the poor victim from the inside out, or the bleating of the young gazelle as it is torn apart by hyenas, or the disfigurement of an innocent human infant from a genetic mutation that lead to a birth defect.
Because of God we humans are called upon to make declarations about the morality of essentially amoral, natural events.
We humans are the moral animals, and our morality is a byproduct of our social natures that are, themselves, an evolved trait that we share with many other primates and mammals (think of whales and dolphins). We understand intention because we are intentional animals, with large brains that have several layers of function piled by evolution on top of our (more ancient) instinctive and reflexive brains. We are able to critique our own behavior and, therefore, have a set of semi-flexible standards for that which is the behavior that we tolerate, welcome or condemn in others.
The problem is that we project our own natural intentionality into a universe that has no idea what we’re on about. A universe, in fact, that has no idea at all. A universe that is open and vast and completely empty of any sort of God we can imagine.
Or at least it better be, or that poor God is going to have some answering to do for every act of cruelty that will end up being charged to his (or her, or its) account.
And this is why seeing nature for what it is proves to be better than the religious/mystical view that many of us grew up with. It turns out that it is God, in fact, that makes nature cruel and capricious. Evolution lets the world be what it is: natural. Which, in turn, frees up a good part of the contents of our brain case to deal with the very real ins and outs of our social interactions with our fellow animals, where intention and morality actually do exist.
Nature is not cruel. It cannot be: it has no mind or heart with which to form any intention at all, whether it be good or evil. Only we higher life forms, and the Gods like us that we imagine, can do that.
“In How to Think Like a Neandertal, archaeologist Thomas Wynn and psychologist Frederick L. Coolidge team up to provide a brilliant account of the mental life of Neandertals, drawing on the most recent fossil and archaeological remains”. (From the publisher’s website)
There’s no getting around it: there are a lot of things we simply cannot know about the past. We have to make inferences based on material evidence, but have no eyewitnesses to tell us if we’ve gotten it right or not (though, having read as much as I have of late about the unreliability of human perception, I’m not sure that we’re not better off without their testimony). We find a bit of scraped bone, a flint spear point, some evidence of a small fire and we naturally try to imagine the scene — a particular moment in time.
The fact is that we can do this by using our knowledge of how modern peoples of all kinds behave (as well as comparisons with our primate cousins). But there is always going to be a bit of fancy in the flights of our imagination.
Having said all of that (whew), the authors of How to Think Like a Neandertal are, at the least, well qualified to do some imagining for us about just what Neandertals were really like. As people like us, but not quite like us.
Neandertals and we modern humans share a common ancestor a long, long time ago. Neandertals moved into Europe and Asia out of Africa, and seem to have lived in those areas for quite a while before we showed up. Of course, we had some more evolving to do (while still in Africa) in order to take our modern form, but having done that it seems very likely that — once we reached those northern latitudes — we had a lot to do with hastening the extinction of the powerful (though technologically and — according to the authors — cognitively inferior) Neandertals.
This is a fascinating and transparent look at what we actually know about our extinct cousins (kissing cousins, one might say, as we now have evidence that at least a little Neandertal DNA worked its way into some modern human populations, but not vice-versa). I say “transparent” because the authors do a fine job of systematically laying out the latest evidence from archeology alongside studies of modern hunter-gatherer societies and chimpanzees (as well as other primates). But then they are also quite up-front about when the flight of fancy departs the runway.
To be sure the imagination is here given more reign than the evidence can confidently support, but the signal achievement of this book is the creation in the reader of a living, breathing, vivid sense of what a Neandertal was actually like. This is a remarkable achievement for a couple of scientists writing for a popular audience. And, naturally, understanding Neandertals provides, by contrast, a deeper understanding of our own evolved humanity.
This is the kind of science writing that welcomes this previously (overly) strange and exotic “other” humanoid back into the fold of the actual family of cousins that we all are (well, were). The mind-blowing fact is that we modern humans were occupying the same landscape as Neandertals as recently as 30,000 years ago.
The final chapter is a quietly moving guess at how the final Neandertals drifted into extinction. Reading it, I was reminded of the tale of Ishi, the last surviving man of the Yahi tribe in California that walked out of the mountains one day (shortly after the turn of the 19th century) and was taken in by a scientist who took care of him and tried to learn all he could about his about-to-become extinct culture. For the Neandertals — like the Yahi — there came a point where their remaining groups were simply too small to replace themselves, and one day, those many years ago, the last Neandertal died, alone.
This is a good book — and a pleasurable, often fun read. I highly recommend it.t.n.s.r. bob
We’ve all heard it: one half of a cell phone conversation.
“Nothing. Just waiting to pay for my groceries. What are you doing?”
Someone in their pajamas, at the grocery store, having all appearances of nowhere to rush to, and nothing pressing to do, nevertheless carries in her hand the technology to talk to anybody about nothing anywhere she wants to.
Our communications technology, it seems, has far outstripped our capacity to come up with something worth saying. It makes me wonder just what it is that we’ve done with our much-vaunted ability to talk. Though the creationists among us may see ourselves as the ultimate “purpose” of life on earth, I’m fairly certain that the rest of the animal kingdom is not (The Jungle Book’s King Louie’s plea of “I wanna talk like you” notwithstanding) desirous of our position.
Birds talk all the time. I often wonder what it is that they find to talk about. After all, how complex can the internal life of a grackle or sparrow be? Maybe, for them, chirping is the calming act of repetitive sound making — sort of a sing song meditation.
Whales, I think, would really have something to say. They live for a very long time, and must have interesting interior dynamics of affection, memory and even wisdom. But, alas, they do not possess verbal language. They do have a capacity for communication, to be sure (and something to say, I expect) but it is limited to clicks and rumbling sounds. They simply have not been endowed by evolution with the mechanical capacity for speech. Why not? Can’t they simply “evolve” a voice box and the brain parts to activate it?
This question seems almost reasonable when seen in the light of the way evolution is often discussed in the popular press. The language we use to describe evolution almost invariably borrows words that indicate intentionality: a shark is described as a perfectly-designed killing machine, we are told that dinosaurs evolved feathers and turned into birds, humans in higher latitudes developed blue eyes and narrow nostrils (as if they all got together one day and just decided to “do it”).
And this, it turns out, is a rather big deal, and it points us to a fundamental misunderstanding of evolution that is as maddening as it is widespread: individuals don’t evolve, populations do.
And populations evolve because of the way we reproduce: we make babies by combining the genetic material of two parent animals to form a new, single cell. Once that cell starts dividing, there is a whole lot of copying and duplicating of genetic code going on. And, like any such complicated endeavor, mistakes are made. Most often, these mistakes do not cause harm. But many times they do, and that future individual animal could be in serious trouble if the mistake is in a place in the DNA that causes a severe malformation (a missing limb, a heart condition, a lack of a pain response).
Most often such damaged fetuses are aborted spontaneously by the mother’s body before she even knows she’s pregnant (current estimates are at 50% among us humans). But just every so often (it doesn’t have to be very often, when you take into account the long years over which evolution and natural selection have had time to “work”), a mutation occurs which provides some tiny, incremental benefit to the animal that has it. In nature, it doesn’t take much — a touch more speed or agility, or a shred more smarts — to give you an advantage. In fact, giant leaps of change are most often disastrous and, frankly, wasteful (there is a reason we have the body shapes we have and the huge brains to run them — but as it is we are living right at the hairy edge of disaster as women often have a very challenging time getting that huge human head safely past their narrow pelvises).
A lot of the idiocy around intelligent design has to do with a belief that one animal simply decides, one day, to turn into another animal. And, since we don’t see that happening around us, evolution must be a fallacy. Of course, evolution and natural selection aren’t based on decisions at all. There is no “force” behind it that thinks about anything at all. It is simply a process in which the success of any and all life forms is the product of the inherited characteristics of that particular life form in a particular environment. If an environment is stable over time, then life forms will inevitably adapt to it (or fail to, and die off). So that throughout the history of this planet, life forms that began as the most basic of units have had time and opportunity to keep on reproducing, over and over, mixing and mutating their DNA until, due to an ever-increasing accumulation of those one-in-a-million (or billion, or trillion, or???) beneficial inherited traits, you end up with entire animals built up of cooperative collections of bacteria and bone and muscle and blood.
At some unknowable and uncountable moments in our human reproductive history, the genetic frameworks for our capacity for verbal speech were set in place. They did not evolve in order for us to speak, they just happened, bit by bit until, by chance, some sort of functional unit took shape that gave the first human that could grunt a slight advantage of the one who only squeaked and, voila, a line of grunting descendants was set to become dominant. The rest, as they say, is history. And this is the way that a bacteria becomes a mutlicellular creature, and then a fish and then a talking, thinking human being.
But it’s more complicated than just evolving the mechanical equipment of a voice box activated by air flowing from our lungs. Surely the nature of our language shapes our thought. We rightly wonder whether the internal, cognitive complexity of animals isn’t itself limited by a lack of verbal language (or, conversely, greatly enhanced by it). After all, it is our language — our words with their shared meanings — that provides the sort of filing system of our experience of living. Without language, I think much of our memory and ideas would remain undifferentiated, like our memories of very early childhood (or even of our birth).
(I mean, surely we were conscious during all of those early experiences, but they are ideas we had before we had words to form ideas with. They are like digital files from our first computer in a program that no-one has anymore. The data is surely locked in our minds, but we cannot access it).
Such is the power of language.
And this is also why we will never be able to talk to the animals. As much as we are able to communicate with chimps and dolphins and dogs and cats, we can’t actually talk with them. We do share a very real understanding, at times, with other creatures. But it is not simply a problem of translation (in the way it might be when trying to talk to another human who does not speak our particular language). For we don’t even know how whales, say, file the memories and ideas that they have. To read a whales mind would pose the same problems as trying to recall the pre-language experience of our own birth: how can we translate thoughts that were not recorded in any language?
It’s like the aging floppy disks that I keep in now dusty boxes…well, sort of. For though those disks carry data in an actual language readable by an actual (if out-of-date and-hard to-find) technology, they will soon be, for all practical purposes, impossible to read. The difference is that our pre-language memories (and likewise, one assumes, the thoughts of the whale) were never recorded in a language at all.
As one scientist said to me: what we really assume in our inter-species communication fantasies is that the other animal will learn our language, and tell us what he or she is thinking. But for that to happen, that animal would have to evolve the brain and body structures that we did. And since evolution is not directed, there is no reason to expect them to do that over the next million years or so. But even if they did, they would no longer remember life without language, and could not tell us some of the secrets to our own wild past that we seek.
So what we really hope for, I think, is for a dolphin to suddenly start talking to us. But it should be obvious by now that this is a fantasy. For that magical talking dolphin, too, would have no access to its pre-verbal memories (unless it were, truly, “magical”). This is why the notion is such a potent subject for fantasy in film and fiction. It’s appeal is only outweighed (or perhaps enhanced) by the sheer impossibility of it actually happening.
I think we should be appreciative of both the benefits and limitations of our unusual capacity for language. I coo at dove, or moo at cows all the time, and talk to cats and dogs as if they have a clue. It amuses me and doesn’t traumatize the animals. And it serves as a kind of wry reminder that we humans are in this talking life alone, together. Our capacity for verbal language is one of the highly unusual products of an incredible series of tiny historical mutations that had to rise or fall in our population in the living conditions of untold numbers of individual lives.
And make no mistake: our capacities evolved step by step, always built upon the body plan that came before. There is nothing “irreducibly” complex about us. We see analogues to our own eyes and hands and throats and minds in the animals around us. They echo our sameness and shed light on our uniqueness. It is a wonder that the whales would probably enjoy talking about. If only they could.
Or maybe, like us, they’d quickly run out of things to say. And then we’d be reduced to visiting them at Sea World where, instead of thrilling us by leaping out of water for their wet-suit clad trainer, they would instead entertain us by chattering endlessly on their own whale-sized cell phones: “Oh nothing. Just jumping for some fish. What are you doing?”