Ghosts of Evolution

[HT: brain pickings]


Age of Dinosaurs

The first of the dinosaurs appeared around 231 million years ago, and they dominated earth for more than 135 million years. Homo Sapiens, on the other hand, evolved only around 200 thousand years ago. Here’s a chart to help put this into perspective (click to embiggen):


[Pic courtesy: Wikipedia]

Previous “Sense of Proportion” posts: IIIIIIIVVVI.

Survival Machines

theselfishgenePublished in 1976, The Selfish Gene remains one of the most influential scientific books I’ve ever read. In this book, Richard Dawkins introduced the novel concept of the replicator: “the initial molecule that managed to reproduce itself and thus gained an advantage over other molecules within the primordial soup.” I was flipping through the first chapter of this book a few days ago, and the following passage gave me goosebumps all over again:

Four thousand million years on, what was to be the fate of the ancient replicators? They did not die out, for they are past masters of the survival arts. But do not look for them floating loose in the sea; they gave up that cavalier freedom long ago. Now they swarm in huge colonies, safe inside gigantic lumbering robots, sealed off from the outside world, communicating with it by torturous indirect routes, manipulating it by remote control. They are in you and me; they created us, body and mind; and their preservation is the ultimate rationale for our existence. They have come a long way, those replicators. Now they go by the name of genes, and we are their survival machines.

Take a moment to grasp the profundity of this rather unnerving passage. It begins to set-up the central premise of this iconic book, and its many-fold implications are unraveled with elegant prose and extensive detail.

Among other things, this excerpt alludes to the prevalence of behavioral traits that may not be beneficial to an organism (i.e., the vehicle) but still exist because they are favorable to the the genes (i.e., its drivers). The selfish genes do not “care” about their vehicle insofar as it can be used and manipulated for its own survival. Often, there’s no conflict between the long-term survival goals of the genes and and short-term survival motives of an organism. The gene’s longing for eternity is in accordance with an organism’s desire for a long life. But there are exceptions.

Consider the male spider, for instance. The sexual impulse of a male spider is beneficial to the “spider genes” because a potential copulation with a female spider increases their chances of surviving yet another generation. However, this often gets the male spider killed — by getting eaten by the female spider. Good for the spider genes, not so much for the poor male spider. Similarly, there are human traits and impulses that may be unfavorable to an individual, but are necessary for the survival of our selfish, manipulative genes. When I first read this book many years ago, this revelation blew my mind. It left an indelible impact on my understanding of evolution, and continues to shape my worldview even to this day.

The Watchmaker Argument

One of the most popular arguments in support of God’s existence is what’s called the watchmaker argument: the world is so complex and refined that there must be a designer. Without an intelligent designer, the existence of such an intricately beautiful world is impossible. This theological argument – that design implies designer – is attributed to Paley, and I’ve heard several versions of this improbability argument during religious discourses over the years. Daniel Dennett calls it one of the oldest ideas known:

[T]he idea that it takes a big fancy smart thing to make a lesser thing. I call it the trickle-down theory of creationism. You’ll never see a spear making a spear maker. You’ll never see a horse shoe making a blacksmith. You’ll never see a pot making a potter.

Richard Dawkins refers to another metaphor (attributed to Hoyle) in his book The God Delusion:

[T]he probability of life originating on Earth is no greater than the chance that a hurricane, sweeping through a scrapyard, would have the luck to assemble a Boeing 747. […] The odds against assembling a fully functioning horse, beetle or ostrich by randomly shuffling its parts are up there in 747 territory.

This is indeed a strong argument. The biological complexity and diversity of life on Earth seem to, quite logically, require an intelligent designer; it all just can’t happen by chance alone.

However, when analyzed throughly, the argument can be shown to have a circular logic, and instead of proving the necessity (and hence, existence) of an intelligent designer, it works in the opposite direction. The self-refuting idea of ‘an intelligent designer responsible for design’ doesn’t solve the problem, it just passes the baton, and raises another question.

Any entity capable of intelligently designing something as improbable [as a universe] would have to be even more improbable than [the universe itself]. Far from terminating the vicious regress, God aggravates it with a vengeance.

The improbability argument states that the universe is too complex, ergo there must be a God. But then God himself/herself/itself must be even more complex than the universe. Who created God? You can easily see how this can spiral out to an endless regress. The only way you can get out of it is by saying something like ‘No one created God.’ But then why not make the same argument for the universe itself?

What is the solution then, to this problem of improbability? Well, to understand the solution, the first roadblock that needs to be cleared off is the wrong assumption that chance is the only possible alternative to intelligent design.

A deep understanding of Darwinism teaches us to be wary of the easy assumption that design is the only alternative to chance, and teaches us to seek out graded ramps of slowly increasing complexity. Before Darwin, philosophers such as Hume understood that the improbability of life did not mean that it had to be designed, but they couldn’t imagine an alternative. After Darwin, we all should feel, deep in our bones, suspicious of the very idea of design. The illusion of design is a trap that has caught us before, and Darwin should have immunized us by raising our consciousness. […]

Natural selection is not only a parsimonious, plausible and elegant solution; it is the only workable alternative to chance that has ever been suggested.

Understanding Darwin’s theory of evolution by natural selection removes the necessity of an intelligent designer. And God suddenly finds himself left with fewer things to do than before. What shouldn’t be surprising here is that science has consistently done this over the years: shrinking God’s circle of influence. We have come long way from superstitious mythologies —  draughts are caused by angry gods etc. — to the current understanding of the universe that leaves fewer things left for God. This, of course, is a continual process. One of the things that makes science awesome is its denial to admit that we’ve reached a final, ultimate, unchangeable truth. (All scientific truth is provisional.) However, this doesn’t stop the theists to proclaim that science does not have all the answers.

Creationists eagerly seek a gap in present-day knowledge or understanding. If an apparent gap is found, it is assumed that God, by default, must fill it. What worries thoughtful theologians […] is that the gaps shrink as science advances, and God is threatened with eventually having nothing to do and nowhere to hide.

Jerry Coyne hits the nail on the head:

Why is God considered an explanation for anything? It’s not – it’s a failure to explain, a shrug of the shoulders, an ‘I dunno’ dressed up in spirituality and ritual. If someone credits something to God, generally what it means is that they don’t have a clue, they’re attributing it to an unreachable, unknowable sky-fairy. As for an explanation of where that bloke came from, and odds are you’ll get a vague, pseudo-philosophical reply about having always existed, or being outside nature. Which, of course, explains nothing.

On that note, here’s a hilarious comic by Jesus and Mo.

[The quotes are from Richard Dawkin’s The God Delusion. Emphases are mine. Image courtesy: Wikipedia]

Rainbows Have Seams

Did you know that the Japanese people call their traffic light ‘blue’ when it turns on? This is not because the third color – apart from red and orange – in their traffic lights system is blue; it looks exactly the same as it does everywhere else (i.e. green). It’s just that for centuries they didn’t have a separate name for the color blue. For them, blue and green are just two different shades of the same color which they call Ao. I didn’t know this surprising fact until I first saw this tweet, and then read this lovely post.

This implies that when the Japanese look at a rainbow, they recognize six distinct colors, not seven. Are they mistaken? Of course not! The choice of seven colors is arbitrary anyways. There are in fact infinite number of colors in the rainbow, which is a continuous spectrum of colors rather than a collage of seven discrete colors. There are no natural boundaries in the frequencies of visible light. It just so happened that Sir Issac Newton defined seven distinct colors because he thought that the number had some mystical, divine properties (seven days of creation, seven musical notes etc.) and that definition persisted till this day.

Now, there are other languages too that have fewer names for colors than the modern standard of ROYGBIV. You may wonder, what difference does it make if some societies have fewer names for colors? When they look at the rainbow wouldn’t they see exactly the same thing as we do? Well, as it turns out, language and words (or the lack thereof) do shape the way we perceive the world. But before we get into that, here’s a thought-provoking excerpt from the blog post I mentioned above:

Imagine that you had a rainbow-colored piece of paper that smoothly blends from one color to the other. This will be our map of color space. Now just as you would on a real map, we draw boundaries on it. This bit here is pink, that part is orange, and that’s yellow. Here is what such a map might look like to a native English speaker.

But if you think about it, there’s a real puzzle here. Why should different cultures draw the same boundaries? If we speak different languages with largely independent histories, shouldn’t our ancestors have carved up the visual atlas rather differently?

Apparently, some research had been done to answer this question, and it revealed some fascinating insights. It turns out that largely unique and independent cultures do take different evolutionary paths in naming colors. As language evolves, most cultures first come up with words for black and white, usually followed by red. However, eventually they do “somehow gravitate towards the same choices for how to slice up the visual cake“.

The picture that’s emerging is that colors aren’t quite random slices of the visual pie. They’re somewhat basic categories that humans from different cultures gravitate towards, and must have to do with how the biology of how we see the world. In other words, rainbows have seams.

That’s just fascinating to me.


Back to my earlier comment about how languages shape not only the way we talk but also how we think, experience, and perceive the world. In a post I wrote several years ago, I referred to some research that showed how the languages we speak can have a profound effect on the way we think. For example, in a study the participants were asked to describe a key. Half of the participants were native German speakers who used words like “hard”, “heavy” and “metal’ more often than the other participants. The other half of the participants were native Spanish speakers who were more likely to use words like “golden”, “tiny” and “shiny”. The difference in the choice of words to describe the same concrete object can be explained by the fact that the word ‘key’ is a masculine noun in German and a feminine word in Spanish.

The researcher also performed some tests to see whether differences in color language lead to differences in color perception. Indeed, the data suggested that the the Russians were quicker to distinguish between two shades of blue, as the Russian language makes an obligatory distinction between light blue (goluboy) and dark blue (siniy) colors. The English speakers have only one word, “blue”, for both shades and hence were relatively slow in recognizing the shade variance.

In conclusion, she writes:

I have described how languages shape the way we think about space, time, colors, and objects. Other studies have found effects of language on how people construe events, reason about causality, keep track of number, understand material substance, perceive and experience emotion, reason about other people’s minds, choose to take risks, and even in the way they choose professions and spouses. Taken together, these results show that linguistic processes are pervasive in most fundamental domains of thought, unconsciously shaping us from the nuts and bolts of cognition and perception to our loftiest abstract notions and major life decisions. Language is central to our experience of being human, and the languages we speak profoundly shape the way we think, the way we see the world, the way we live our lives.

So when Nietzsche called language a “prison house” and Wittgenstein wrote that “the limits of my language means limits of my world”, they weren’t kidding!

Knowing They Know That You Know

This opening paragraph from an old NYT article tickled my fancy:

(Follow closely now; this is about the science of English.) Phoebe and Rachel plot to play a joke on Monica and Chandler after they learn the two are secretly dating. The couple discover the prank and try to turn the tables, but Phoebe realizes this turnabout and once again tries to outwit them.

As Phoebe tells Rachel, “They don’t know that we know they know we know.”

“This layered process of figuring out what someone else is thinking — of mind reading — is both a common literary device and an essential survival skill.”

The human facility of three mental states – the triangularization of minds – is a trait that evolved due to our excessive social interactions. An extension of this triangularization of minds is the concept of common knowledge which was briefly touched in one of the puzzles I posted on this blog: The Blue-eyed Islanders.

[Hat Tip: Cheap Talk]

The Better Angels of Our Nature

I am immersed in Steven Pinker’s engrossing new book The Better Angels of Our Nature that released few months ago. I am not even half-way through this 700-page epic but I can say that it is one of most interesting, thought-provoking, and intellectually satisfying books I have read in a long time. (Bill Gates would nod in approval!)

For the longest time, I have been an advocate of the fact that we live in a much better world today than our ancestors did. The world has become a safer, healthier, peaceable, and in general, better place. We may grumble about how technological advancements have made us lazy and “stupid”, how we have lost touch with the culture and tradition, how were are increasingly becoming less considerate about the climate. But a basic introductory lesson in cognitive psychology will explain how we are inclined to have what’s called “pessimistic bias”: practically every generation believes that their own generation, and especially the next generation, is not up to the standards of their parents and grand-parents. [See my earlier post Cultural Pessimism.] In reality, while there are occasional detrimental effects of modernization, we have grown by leaps and bounds when it comes to timeless intellectual values (like objectivity, truth, factual discovery), physical values (like overall health, safety, life-span), and civil values (tolerance and fairness, liberty, justice).

The Better Angels of Our Nature immensely helped me to consolidate this worldview yet again. The central argument of this book is that we may be living in the most peaceful era of our species’ existence. However,

[t]he very idea invites skepticism, incredulity, and sometimes anger. Our cognitive faculties predispose us to believe that we live in violent times, especially when they are stoked by media that follow the watchword “If it bleeds, it leads.” The human mind tends to estimate the probability of an event from the ease with which it can recall examples, and scenes of carnage are more likely to be beamed into our homes and burned into our memories than footage of people dying of old age! No matter how small the percentage of violence deaths may be, in absolute numbers there will be always enough of them to fill the evening news, so people’s impression of violence will be disconnected from the actual proportions.

Pinker starts with an elaborate exploration of our evolutionary instincts that make us violent. Drawing from one of his favorite philosophers, Hobbes, he explains how there are three incentives of violence that applies to members of an intelligent species: competition, diffidence/fear, and glory. This discussion leads into some fascinating concepts, like the Hobbesian trap and Prisoner’s dilemma, that I was familiar with but never considered them from such distinct vantage point. The psychology of violence remains the main focus for a large part of this book. For me, those are the most interesting chapters. Once that foundation is established, he marches on to persuade the reader that violence has gone down over the years. By using myriad data sources, statistics, and illuminating charts he portrays a robust picture of the gradual, persistent and unmistakable retreat from violence over time. The first major shift in the trend came when we settled down into agricultural societies. The production, preservation and protection of crops eventually led to administrative mini-states that further reduced violent feuds and confrontations. There were other major factors that Pinker delves into, like commerce and women empowerment, each having a profound impact on our retreat from violence.

One of the most important points he makes is that not only violence has declined over time, but our tolerance towards violence has also waned. As a result, we are more sensitive to a level of violence that may be pretty mild stuff by historical standards. Due to this heightened sensitivity, when we see violent crimes, we focus on how low our behavior has sunken, not on how high our standards have risen.

Now, modern technologies have produced lethal weapons that can wreck mass destruction on the scales that were unimaginable to prior generations. Pinker is not claiming that everything has improved, neither does he ignore the fact that our retreat from violence may not necessarily continue into the future. But the arc of history is certainly in the positive direction – understanding that is essential if we were to truly reap the benefits of living in a (relatively) peaceful society and even more importantly, maintain the growth curve to build more peaceful societies.

The conventional view that glorifies the past, and laments the current state of the society, is seriously flawed. This book is a powerful blow to that romanticized nostalgia. However, this is also a very long book – a serious and monumental study, albeit filled with a lot of humor, wit, and interesting tidbits from the history – so I would recommend it to only those who are keenly interested in this subject. For all others, the book can get a bit too comprehensive and exhaustive. Instead, this brilliant TED talk (by the man himself) should suffice:

Survival of the Sneakiest

I have previously written a post about how natural selection doesn’t necessarily lead to the best or the most optimal designs. Like the classic example of the QWERTY keyboard, evolution is not about what’s best. It’s about whatever works.

Well, here’s a comic that explains this – with an example of a sneaky cricket. It’s a bit long but amusing; not very refined, but succeeds in conveying an important lesson in understanding evolution… And there’s a bonus trivia about those annoying cricket chirps at the bottom of the comic!

[Click to embiggen. It might be easier to read it on the original link.]

The Argumentative Theory

Here’s one of the most thought-provoking quotes I read recently:

Reasoning was not designed to pursue the truth. Reasoning was designed by evolution to help us win arguments.

We think we use reason to enhance decisions making and improve knowledge. But more often that not, when we think we are reasoning, we are merely trying to rationalize a conclusion that we’ve already made. Reasoning often equates to justifying an existing belief as opposed to getting at a better belief.

A recent white-paper proposes a hypothesis that the function of reasoning is not truth-seeking but argumentative. We use reasoning to devise and evaluate arguments for persuading others and ourselves. They conclude that while reasoning makes human communication more effective and potent, it not only falls short of delivering rational beliefs and rational decisions reliably, but it may even be detrimental to rationality in many cases.

This explains why humans reason rather poorly, and are vulnerable to cognitive biases such as confirmation bias.


The quote is from the recent edition of Edge online magazine, and the white-paper is available here for free.

The Mediocrity Principle

Some of the most brilliant minds on our planet respond to this year’s Edge question suggested by Steven Pinker. The question is: What scientific concept would improve everybody’s cognitive toolkit?

There are many good entries but I was especially intrigued by the responses from Sean Carroll, a Theoretical Physicist, and P Z Myers, a Biologist. Both argue that the concept that people need to grasp to better comprehend our place in the universe is to understand that we are not special. In Carroll’s words:

This isn’t an obvious way for people to think. Looking at the universe through our anthropocentric eyes, we can’t help but view things in terms of causes, purposes, and natural ways of being. […] Human beings like to insist that there are reasons why things happen. The death of a child, the crash of an airplane, or a random shooting must be explained in terms of the workings of a hidden plan. When Pat Robertson suggested that Hurricane Katrina was caused in part by God’s anger at America’s failing morals, he was attempting to provide an explanatory context for a seemingly inexplicable event. [more]

Myers calls it the “mediocrity principle”:

The mediocrity principle simply states that you aren’t special. The universe does not revolve around you, this planet isn’t privileged in any unique way, your country is not the perfect product of divine destiny, your existence isn’t the product of directed, intentional fate, and that tuna sandwich you had for lunch was not plotting to give you indigestion. Most of what happens in the world is just a consequence of natural, universal laws — laws that apply everywhere and to everything, with no special exemptions or amplifications for your benefit — given variety by the input of chance. Everything that you as a human being consider cosmically important is an accident. The rules of inheritance and the nature of biology meant that when your parents had a baby, it was anatomically human and mostly fully functional physiologically, but the unique combination of traits that make you male or female, tall or short, brown-eyed or blue-eyed were the result of a chance shuffle of genetic attributes during meiosis, a few random mutations, and the luck of the draw in the grand sperm race at fertilization. [more]

This has been a recurrent theme on this blog (see, for instance, Seekers of Depth and Profundity). Our innate proclivity to seek deeper and hidden meanings in everyday events, struggles and conflicts is responsible for making us seek higher meaning in the existence of life itself. But science (more specifically, evolution) tells us otherwise: we are products of a random, unsupervised and impersonal process. Just like apes, monkeys, whales, bugs, worms and bacteria. Our existence is not a part of any Grand Scheme (supervised by a Supreme Being). We just exist.

However, this needn’t be disheartening. Carroll sums it up succinctly:

None of which is to say that life is devoid of purpose and meaning. Only that these are things we create, not things we discover out there in the fundamental architecture of the world. The world keeps happening, in accordance with its rules; it’s up to us to make sense of it and give it value.

P. S. All entries can be found on the Edge web-site (link). Do check out We are Lost in Thought by Sam Harris, and Positive-Sum Games by the man himself.

Enter your email address to subscribe to this blog and receive notifications of new posts by email.

Join 66 other followers

On Twitter