Tag Archives: Evolution

From Simplicity to Complexity

What makes the existence of life and the universe seem so improbable? Without question, the incredible complexity of all things is at the heart of the improbability dilemma. And it requires some form of explanation. In order to properly examine improbability, we must first address complexity. How can complexity be explained?

The complexity of the universe is staggering, in some ways beyond human understanding. For many, this fact alone can’t be accounted for without a design, particularly when the only alternative considered is chance. With this comparison, design usually wins over chance, and design implies a designer. Ancient civilizations observed a universe that was much simpler—in their eyes—than the universe we know exists today. Nevertheless, it would have appeared complex enough to invoke a designer. Even a number of natural phenomena that are easily explained today were attributed to gods.

Our present understanding of the universe reveals a universe that is far more complex than the ancients could have imagined. We have the opportunity of looking back in time for answers—back to a time when the universe wasn’t nearly as complex. Through a series of scientific discoveries, simple origins were found to be the precursors of the present universe.

Darwin opened our eyes, albeit slowly, with his insights on evolution. As it pertains to life, Darwin showed us a different way of thinking about the emergence of life. His theory of evolution by natural selection broke down the complexity of life into incremental steps. He managed to shift the focus from the finished product (or the present product) to the steps that led to it. According to Darwin, and verified by other more recent discoveries, life has evolved from simple beginnings—simple relative to its present state. It all began with single cell organisms, and perhaps only one. Now we have a world full of diverse and complex life forms, some containing trillions of cells. Darwin showed that from simple origins, complexity could arise over time, and by a natural process.

Even the life that we see today starts simple, and grows in complexity. For example, a tree begins with a single seed, and grows to a complex structure of roots, branches and leaves. When I look at a seed I find it difficult to imagine that a tree can come out of it, and yet it does so naturally. Like the seed of a tree, a human being also has a simple beginning—we were all initially a single cell. You could make the argument that a cell is complex on its own, and it is, however, millions and trillions of cells working in unison is several orders of magnitude more complex. Keep in mind that what we classify as the origin of life—a single cell—is somewhat arbitrary. Even a cell has to be constructed from simpler chemical processes, which at some point we call life. Although life, especially the origin of life, is an amazing and mysterious process, we can clearly see that it moves in a direction from simplicity to complexity.

Now let’s turn our attention to the universe as a whole, and see if the same principle applies. After Darwin had provided an explanation for the evolution of life, it was not automatically assumed that the universe evolves by a similar process. In fact, the idea that the universe was eternal and unchanging was a long-held belief by the general population and scientists alike. This idea took some time to overthrow. But by the mid-twentieth century, new discoveries were pointing directly towards an evolving universe; one which had a beginning.

The big bang is analogous to a cell. Just as a single cell can be viewed as the origin of life, the big bang can be viewed as the origin of the universe. And as I mentioned earlier, a cell can also be thought of as complex, but nowhere near as complex as the life that arose from it. The universe can also be viewed in a similar light. Although the big bang was not necessarily a simple event, it was nonetheless simpler than the universe that emerged from it.

Scientists theorize that a substantial amount of activity occurred at the initial moment of creation. The basic forces of nature emerged (gravity, electromagnetism, and the strong and weak nuclear forces), as well as a host of elementary particles (such as photons, protons, neutrons and electrons). Space and time as we know it were also created.  All that and more happened in a tiny fraction of a second. On the surface, this seems to present a problem as far as a simple beginning is concerned, however, there is more to consider.

In spite of this initial creative activity, for the first 300,000 to 500,000 years the universe was nothing more than an enormous cloud of hot expanding gas. Complexity would then increase gradually over time—in a sort of cosmic natural selection. It took one billion years before stars and galaxies formed. A few more billion years before supernovae explosions (the death of stars) created and distributed the heavier elements necessary for life. Simple life on earth emerged 9.9 billion years after the big bang. And from there it would take over 3 billion years of evolution to arrive at modern humans. From this simplified timeline, we can see that the early universe was much simpler than it is now—the result of 13.7 billion years of cosmic evolution.

There is another point worth noting that relates to the discussion. The big bang theory is a theory that describes the universe a fraction of a second after the universe came into existence. The big bang theory is silent on the cause of the creation event. Although scientists speculate on what the cause may have been, the big bang represents the edge of our present ability to understand the universe, a theoretical time barrier that we have not yet crossed. I like the way Bill Bryson wraps up the discussion regarding the cause of the big bang. In  A Short History of Nearly Everything, he writes:

“… it may be that space and time had some other forms altogether before the Big Bang—forms too alien for us to imagine—and that the Big Bang represents some sort of transition phase, where the universe went from a form we can’t understand to one we almost can.”

Like a cell, which is created by more elementary processes, the big bang could have been a transition phase that was precipitated by a simpler pre-existing cosmos. Some scientists even suggest that the universe may have been created out of nothing. And by nothing, I don’t think they really mean nothing, but perhaps something very small that we don’t completely understand. Physicists now believe that you have to incorporate aspects of the quantum world in order to understand the big bang. And if you go by quantum theory, particles can spontaneously come in and out of existence from nothingness. That is the nothing that scientists are talking about. Bryson writes: “It seems impossible that you could get something from nothing, but the fact that once there was nothing and now there is a universe is evident proof that you can.” Therefore, if the universe was created from nothing or very little, you can’t get much simpler than that. And if this is even remotely correct, the principle of things moving from simplicity to complexity definitely applies to the universe as a whole.

Having said all that about complexity, let’s insert improbability into the equation. Both life and the universe evolved from simple origins, and through incremental steps, have grown in complexity. Although this does not explain how the simple origin came about, it does show that complexity can be achieved by gradual steps, even if the finished product seems improbable—improbable by means other than design. Also, an after the fact approach of looking only at the finished product can be deceiving, that is in terms of what improbability entails. If something is improbable, does it mean that it can’t happen? And because the existence of life and the universe appears improbable, does it mean that it came about by design?

Let’s begin with a simple exercise. Do you remember what you did yesterday? I mean everything you did yesterday. If you went to work, think about the route you took, and the exact location of the cars you passed. What about the people you met and the exact time you met them. Then there are the phone calls or emails you received. Where did you have lunch, what did you eat, and with whom? What tasks did you perform? And what about after work, what else happened? You get the idea. Although you may think you had an ordinary day, the fact is that the exact details of your day will never happen again. Yesterday, just as it occurred, was extremely improbable. And today, tomorrow, and every other day will unfold in a way that is also improbable.

Now let’s look at another example, something more profound than an ordinary day—your own existence. In order for you to have a life, an almost endless series of events had to occur. Think about the coupling of your parents, and their parents, and every ancestor that came before that. In order for you to exist, every combination of ancestors had to mate, and possibly at the exact time that they did. I will spare you the trouble of going any further down the evolutionary line, but the basic idea is that your life is extraordinarily improbable. And so is my life and everybody else’s. Just because something is improbable, does not mean it can’t happen. The fact is that as long as you have a universe, something has to happen, and that just about everything that happens is improbable.

Therefore, if improbable things happen all the time, does it have to come about by design? I am certain that many would say that it does. They could also argue that the existence of life seems so improbable that it implies a higher order to the universe. Although that may be true, it does not necessarily mean that life was designed. The universe’s enormous scales of time and space allows for limitless opportunities to create. Given the mind-boggling numbers that are involved, what seems improbable or impossible does not necessarily apply to the universe.

We know that the universe allows life, because we find ourselves on a planet that allows life. On the other hand, on all the planets that don’t allow life, there is no one to count the failed attempts, or whether any attempts were made—no one to contemplate why it wasn’t designed to allow life to exist, or if it was designed at all. Although we can’t definitely confirm that life exists elsewhere, we know that life is rare relative to the size of the universe. If life was plentiful, we probably would have found some elsewhere by now. This means that vast regions of the cosmos are without life. And if we could closely observe those regions, we wouldn’t think that they were anything special. We would see planets orbiting stars and swirling galaxies, but this would go on for eons, without any conscious experience. Keep in mind that the process that led to life here on earth is essentially the same process that led to the lifeless regions. Of course, there are a few exceptions. One of which is the earth’s special location.

The location of the earth is an example of something that appears improbable, and thus appears designed. The earth’s location has been called the Goldilocks Zone, taken from the fairy tale Goldilocks and the Three Bears. The obvious reason being that its location is just right (just the right distance from the sun to support life). Of all the possible locations that couldn’t support life, why here? Again you could say that it is by design. But it doesn’t have to be, simply because improbable things can happen, especially with large scales like the universe. With a universe as vast as ours, it is inevitable that some planets will be located in Goldilocks Zones. It may be that we just happen to be here. Not necessarily because it was designed that way, and not merely by chance. But rather by an evolutionary process on a cosmic scale, which moves in a direction from simplicity to complexity. It is a process that creates stars, galaxies, and planets. Sometimes when the conditions are just right, it creates life.

Goldilocks Zones are not only applicable to planets, but the same principle is also present in nature. For instance, let’s examine something that is closer to home, such as the life cycle of a tree. A mature tree can produce at least several thousand seeds in a growing season, which are eventually deposited on the ground. The vast majority of these seeds will never become trees. Usually, only a very small percentage will germinate and grow to become trees. They are seeds that fall in Goldilocks Zones. In this context, a Goldilocks Zone would include fertile soil, sufficient water, sunlight, shade, etc. The probability of any one specific seed becoming a tree is very remote; however, when all the seeds are taken into account, probabilities can be viewed in a different light. We know that some seeds will become trees, because they will benefit from conditions that are just right. What we don’t know is which seeds will be selected by this process.

There is another analogy that I have heard a few times, which deals with the improbability question. This analogy has been used in support of design, and it goes something like this: the world’s oceans, with the comings and goings of its tides and waves could never construct a sand castle. The argument being that it requires a design for something constructive to emerge, and this applies to all the complexity we see today. The problem with this view is that it evaluates design against only one other alternative—whether chance alone could construct the sand castle.

There is another way to look at this analogy, which in my opinion, better shows how seemingly improbable things emerge. I agree that the ocean could not directly construct a sand castle, but it could do so indirectly. Life emerged from the ocean, and gradually made its way on land, and over billions of years evolved into more complex forms. One of these forms, a child, walked on the beach and built a sand castle. Consequently, the sandcastle came about from a complicated natural process that can’t be broken down into simplistic explanations, such as the polar opposites of design or chance. If we could go back in time a few billion years, we would think that the likelihood of a sand castle appearing on any of the world’s beaches would be very low. And yet today, sandcastles regularly appear (and disappear). Therefore, whether we are talking about living planets, trees, or sandcastles—and even if the finished product seems improbable—it doesn’t mean it can’t happen.

 

References: Bill Bryson, A Short History of Nearly Everything (London: Black Swan, 2004), 31, 32.


 

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Living in a Medium-Size World

The human experience is limited by the range of our senses. We can only see, hear, touch, smell and taste so much. Our sensory input is the result of the world directly around us, and that is what we perceive as reality. Humans have evolved to intuitively deal with the medium-size world. Hidden from us are the microscopic realm and the large-scale universe. In addition, we are not well equipped to deal with things moving at light speed and extreme time scales (sometimes called deep time).

universe-telescopeTo a large extent modern science has advanced due to decoding the small-size world and the large-size world. The current picture of the universe is defined by technologies that probe realities beyond the human senses. Scientists have come to the realization that human intuition is deceptive in understanding how the universe works. For example: the behavior of atoms, the formation of stars and galaxies, the speed of light, and the evolutionary timeline. This creates a gap between knowledge and perception, which demands a stretch of imagination to bridge the gap. It may even be wise to expect that new scientific discoveries will be counter-intuitive, just like many significant discoveries from the past.

 Some People Can’t Go There

Why are some people able to digest objective scientific information, while others can’t get beyond their subjective experience? In other words, to expand our world view we need to look outside ourselves. An individual’s life experience is by far too small a sample size to make any meaningful conclusions, particularly when examining some of life’s big questions. There is tremendous variety in life experiences, both in time and geography.

Before modern science the earth was viewed as the center of existence; humans were the focal point of all life and the universe. Now the message is clear that humans occupy a planet that is a tiny part of a much grander scheme. Human life is also a brief existence in an epic evolutionary tale of innumerable life forms. An appreciation of the modern scientific view requires we look beyond our direct experience and consider a reality foreign to ourselves. It is a challenging mental and emotional exercise to honestly look at life from a truly universal perspective.

Albert Einstein was a revolutionary thinker and well-known for his thought experiments. It was by first imagining physical scenarios that he came up with his great insights. He is quoted as saying:

“The true sign of intelligence is not knowledge but imagination.” and “Logic will get you from A to B. Imagination will take you everywhere.”

A Miss-Match Between Intuition and Reality

If we had to find candidates for the most influential and revolutionary scientific theory of all time, at a minimum the list would include: Newton, Darwin, Einstein and the quantum theory scientists. These three individuals and the group of scientists that formulated quantum theory have created the foundation of modern science. Newton’s ideas describe the physics of our everyday reality. Einstein worked out the precise laws of space, time and the large-scale universe. Quantum physics describes the atomic and subatomic realm. And Darwin’s theory of evolution is the cornerstone for studying all life.

quantum-universeAn interesting angle with these landmark ideas is that they are all counter-intuitive. These theories are defined by hidden realities that required great minds and creative techniques to uncover. It is not clear whether others could have come up with similar discoveries; however, I think that few thought along those lines. In the early years of science, knowledge of the world was limited to the human senses. The idea that to accurately describe our world required a leap beyond the sensory experience of the medium-size world must have been revolutionary. Today, scientists and philosophers have come to accept theories based on evidence, even if it goes against common sense.

Before Newton no one had considered that the same force was responsible for controlling the orbits of the planets and falling objects on earth. Space and time were believed to be absolute and unchanging before Einstein showed that they were flexible. Life was clearly designed by God (each species set apart in its present form) before Darwin unveiled the mechanism of natural selection as a powerful creator. And in several ways quantum theory is the most bizarre of scientific theories; For instance, even those that work with quantum mechanics can’t explain why light behaves as both a particle and a wave.

If these examples are too abstract for you, consider the deceptive everyday observation of the sun traveling across the sky. In medieval times it was thought to be heretical to suggest anything other than the sun moving around a stationary earth. And today, if we go by our senses alone we would reach the same conclusion. The earth moves, it spins and orbits the sun, but we don’t feel it. To take it a step further, if the sun actually orbited the earth, it would still look exactly the same. How many other things about our world do we get wrong by overlooking scientific facts? This could be due to ignorance, oversight, or possibly by over rating subjective experience.

Evolution is the Big One

charles-darwinDarwin clearly knew the implications of his theory of evolution; perhaps that is why he waited a couple of decades to publish. Evolution, properly understood, solved the great mystery of life’s propagation and overthrew centuries of beliefs. In terms of its philosophical implications, evolution is the most life-altering scientific idea. Yet, it is still not universally accepted or understood. If I was only exposed to one scientific idea, I would pick evolution; it has the farthest reach and most deeply influences us.

We don’t need to know how atoms work or how galaxies form to function in everyday life. Common sense and intuition will serve us well enough in most situations. Understanding evolution is debatable; I think it is very valuable in understanding human behavior and how our lives unfold (not to mention the natural world).

If we neglect thinking in evolutionary terms we can easily be led astray. Take for example the vibrant colors of flowers: We could assume that the flowers are meant for the enjoyment of human observers (designed for our benefit). But we are only bystanders, which have stumbled upon a deeper truth. The colorful flowers have attracted pollinators over long periods of time, allowing seeds to spread. Nature favors brightly colored flowers over duller colors, because they are more noticeable to birds and insects. Generation after generation the colorful flowers have the advantage. It is not about us, it’s about the insects and the flowers. Nevertheless, we are here and can still enjoy the flowers.

The point I am trying to make is that the deeper questions of our lives need a deeper view. We can’t tackle profound questions with the same reasoning that we use to bake a cake or change a tire; a leap of imagination is required. Although we can’t think about the mysteries of life and the universe all of the time, for those that are philosophically inclined, we cannot help but think about it some of the time. Be forewarned that surface impressions are usually not the whole story.

 

References: Brainy Quote, 2001-2016. http://www.brainyquote.com/quotes/authors/a/albert_einstein.html


 

Memes that Make the World

dnaMemes are the cultural equivalence of biological genes. The term meme was coined by Richard Dawkins in the 1976 publication of The Selfish Gene. The premise behind The Selfish Gene is that Darwinian natural selection acts at the level of genes; ultimately, it is genes that guide evolution by controlling the traits in bodies that contain the genes. In order for natural selection to work, there needs to be something like DNA and genes in which information is replicated. There also requires some copying errors so that small variations can occur from one generation to the next. Memes also fit that description.  Memes are ideas that survive in human brains, and similar to genes they can be copied and passed on.

There are many different types of memes: for example, songs, hairstyles, phrases, beliefs, words and manners. In today’s world the word meme has become popular on the internet. Whenever we here that something has “gone viral,” it is often referred to as a meme. In most cases the meme is something trivial, such as a piece of music, a surprising story or a silly video. It spreads rapidly, but usually it will not last very long. However, other memes have a far greater impact on society, and become part of cultural evolution. Or you could say that the memes guide cultural evolution, much like “the selfish genes.”

The Meme Codes

Language may be the key ingredient that allows memes to spread. Like a DNA code, language is also coded information. It comes in the form of letters and words. Speech is one variation of language, which is surely copied, but written language is even more stable as a replicating code.

We can all recall numerous instances when an event is passed from one story-teller to another. In most cases the details in the story changes until we have conflicting accounts. The information is transferred from one individual brain to another, but memories are not perfect and the copies are not exact. However, written language can exchange hands without the story being altered. The stories still have to resonate in people’s brains and the interpretations will vary, but the fidelity of the written word is higher than the spoken word.

Music is another meme that has two routes of transition. 1) Tunes are passed on by hearing the sounds and attempting to duplicate them. If a tune sounds appealing there is a higher chance it will be copied. As time passes the tune will change a bit. 2) Music can also be written in sheet music using mostly symbols. Like written language, the written music will remain close to the original form. One piano player following a sheet music may sound slightly different from another player. But as the song is played by many piano players it will not change significantly.

MathematicsMathematics is a meme of numbers, symbols and diagrams. It is more accurately copied than language, because there is less ways it can be altered. 2 plus 2 will always equal 4. There is an order in mathematics that is self-correcting, although concepts evolve over time with new applications. Language, music and mathematics are coded information that are replicated and evolve in human brains.

Marching on Through the Generations

The idea of generations is different for memes than it is for genes. A different generation for a gene is an offspring, which will carry some of the same genes. For memes, there is a double meaning for a generation. A meme can be passed on from person to person in a single day, or survive for many years. For instance, I tell you an idea, and you share it with someone else. That’s 3 generations, from me to you to someone else. In this scenario the meme could evolve like microbes, where mutations can occur in a matter of days or weeks. The idea will spread quickly, but each person could add to it or leaves something out; these would be mutations of the original idea.

There are also memes that are handed down in the traditional sense of generations, that is, from a father to a son. These memes are long-lasting and could become cultural norms or traditions. For example, holidays are memes that have survived for many years. In many cases the original customs and purposes behind the holidays are lost or changed (at least by some people). Still the celebrations continue and millions of people observe the holidays. Do we know why the colors of Christmas are red and green, or why the Easter Bunny gives out eggs, or why children get candies at Halloween?

Memes Working Together

Similar to a single gene, a single meme has a minor impact. Genes are effective when they combine with other cooperative genes. Memes also combine with compatible memes and also compete with other memes for attention in human brains. One could think of different ideas as a meme pool, which people select (consciously or subconsciously). The memes that work well together will be more likely to be copied. A meme-complex could be copied because it benefits society, but it could also be copied because it aids the propagation of itself. It is not a guarantee that humans will make the best possible choices; there are equal reasons to believe that we will choose unwisely.

football stadiumA sport is an example of a well-established meme-complex. The North American culture is fascinated with sports on a daily basis. Many play sports at local venues; many more watch sports at stadiums and on televisions. What memes could be working together? How about this list: (memes for running, throwing and catching), (memes for competing, winning and losing), (memes for watching, cheering and analyzing). Any stable and self-replicating cultural norm will consist of mutually beneficial memes.

History-Making Memes

Recorded human history is a story of culture. The ideas that populations believed in mass, whether real or imagined, has fueled the events of history. The most influential ideas (memes) have won out over other ideas. Not always because they were better ideas, but because they were more effective at spreading from brain to brain. Historian Yuval Harari writes in Sapiens: A Brief History of Humankind:

… history’s choices are not made for the benefit of humans… There is no proof that cultures that are beneficial to humans must inexorably succeed and spread, while less beneficial cultures disappear.

Religion symbolsThe cultural enterprises that have dominated human life contain large numbers of memes. Such examples are: religion, war, agriculture, kingdoms, art, music, politics, nationalism and science. No one can tell if the history-making memes (or meme-complexes) took the best course of action for humanity. Some did and others did not. Nevertheless, they had the attributes to enter human brains and to be imitated. Our modern culture is formed by memes with the same qualities as the historical memes. That is, copying fidelity, with variation, and wide-spread selection from the meme pool.

 

References: Yuval Noah Harari, Sapiens: A Brief History of Humankind (Canada: Signal Books, an imprint of McClelland & Stewart, 2014).

Richard Dawkins, The Selfish Gene (Oxford: Oxford University Press, 30th anniversary edition, 2006).

Richard Dawkins | Memes | Oxford Union, Published on Feb. 26, 2014. 

Susan Blackmore sobre memes e “temes” – TED Legendado, Published on Jul. 13, 2013.


The Rise of Homo Sapiens

From about 2 million years ago until about 10,000 years ago, the world was populated by at least 6 different human species. They evolved from a common ancestor in East Africa, a hominid called Australopithecus (Southern Ape). Over thousands of years these primitive humans migrated to regions in North Africa, Europe and Asia. It is likely that environmental changes initiated the exodus, and as time passed new opportunities opened up in other lands. The diverse environments caused humans to evolve different survival traits, eventually branching out into several species.

For many years vast distances separated each species, which allowed them to survive independently. For instance: Homo neanderthalensis (Neanderthals) occupied regions in Europe and the Middle East, and Homo denisova (Denisovans) settled in Asia. Homo erectus (Upright Man), the human species with the most longevity (around 2 million years), populated eastern Asia. And a few species, including Homo sapiens (Wise Man), continued to evolve in East Africa. How closely related to Homo sapiens these other humans were is difficult to assess. How were they genetically different? What were their mental capabilities? And how complex were their social structures?

Homo sapiensNevertheless, starting at about 70,000 years ago Homo sapiens began moving north from Africa; they spread into the Arabian Peninsula and Eurasia. This led to direct competition with other humans. It is difficult for anthropologist to piece together what actually happened in the ensuing millenniums. But the Neanderthals became extinct about 30,000 years ago, and all other humans also disappeared (except for the sapiens). The extinction of Homo floresiensis in Indonesia (13,000 years ago) ended the last of the other human species. Interestingly, Homo floresiensis were a dwarf species, which had become isolated on the island of Flores. What caused Homo sapiens to outlive all other human species?

Two Possible Theories

1) The Interbreeding Theory: When Homo sapiens encountered other humans they coexisted peacefully. The species were genetically close enough that they could have interbred. The result being that today’s human population is not pure Homo sapiens, but rather a genetic mix of humans that lived 70,000 to 30,000 years ago.

2) The Replacement Theory: In this scenario, the genetic difference between species was too great to allow for interbreeding. Or possibly the sapiens’ way of life was drastically different from the others, and they had no interest in mingling with them. Or more likely, there would have been an intense competition for resources. Homo sapiens were the winners in a battle for survival. One could entertain a number of possible ways in which the battle could have been fought and won.

New Evidence

Recent evidence has shed light on the competing theories. In 2010 Neanderthal DNA was extracted from fossil remains. Enough genetic material was still intact to map out the Neanderthal genome. A comparison with modern human DNA revealed that 1-4 % of the DNA of people from the Middle East and Europe is Neanderthal DNA.

Several months later a similar analysis was performed from another primitive human. A sample from the Denisova cave in Siberia showed that about 6% of its DNA was found in modern Melanesians and Aboriginal Australians. The Neanderthal and Denisovan findings prove that some interbreeding did occur, but the amount of DNA in modern genomes is still small. This suggests that interbreeding was not the whole story.

The species may have been at a transition phase, in which they were not completely separate species, but merging of populations was rare. The replacement theory still carries a lot of weight in explaining why about 95% of our DNA is pure Homo sapiens. The conclusion being that sapiens essentially drove the other species to extinction. But what was the crucial difference that resulted in one species dominating the landscape?

The Story of Homo Sapiens

When scientists are uncovering evidence from per-historic times there are bound to be gaps in knowledge. Therefore, a fair amount of speculation comes into play. The rise of Homo sapiens from an insignificant animal to one that claimed the globe is remarkable. Especially when you consider that other humans, as far as we know, started out with the same opportunities.

What unique attributes enabled Homo sapiens to become the only human species? Although we are so accustomed to a world with only one human species, it is the rarest of exceptions in nature. In the animal kingdom there are many species of cats, birds, turtles, and whales. Only in modern humans do we find a single unique species.

In the book, A Brief History of Humankind, historian Yuval Noah Harari identifies one critical sapiens trait that allowed our human ancestors to conquer the world. He calls it The Cognitive Revolution. According to Harari, prehistoric sapiens had evolved a rare ability to cooperate in large numbers, and to do so flexibly.

Homo sapien huntersIt was the development of complex language and social structures that set them apart from other humans. They could communicate everyday practical information, such as where and how to hunt and gather berries. In addition, myths, gods, legends and religions emerged at this time. Whether fact or fiction, storytelling allowed large groups to unite and work for a common cause. Stories also made it possible to pass on knowledge and wisdom to the next generation.

Other animals also work together in groups, but their behaviors are inflexible. In order for significant changes to come about, genetic changes have to occur through the process of evolution. This takes a long time, and that is why animal behavior remains consistent from one generation to the next. But this is not the case for modern humans. Our history reveals an unprecedented pace of change with each generation. For the first time in the history of life sapiens were able to adapt using cognitive abilities. Today, humans are the only species that can survive in all land environments and diverse climates. This is mainly due to our adaptability.

 Taking Over the World

Neanderthals

Neanderthals

When the first wave of Homo sapiens arrived in Neanderthal territory, about 100,000 years ago, the Neanderthals forced the sapiens to retreat. Evidence shows that the Neanderthals had large brains, muscular bodies, could withstand cold temperatures and lived in groups. But it is likely that they could not organize in large groups, or share knowledge in the same way sapiens did. 70,000 years ago a second wave of sapiens left Africa and overran the Neanderthals. This time there was no turning back; Homo sapiens gradually settled much of the globe, and all other human species disappeared.

As Homo sapiens discovered new lands they found an abundance of large animals. This may have been fortunate for the humans, but not for the animals. The archeological records show that roughly 1/2 of the large land mammals became extinct during this period. Climatic or environmental changes may have contributed to the extinctions, however, the human invasion is hard to ignore. In every corner of the world, from large continents to remote islands, extinctions followed humans arriving for the first time.

Large prehistoric animals, such as ground sloths, saber tooth cats and mammoths could have been victims of the sapiens success. This was the first wave of extinction caused by human activity. But they could not have known the full impact of their actions, nor could they have imagined the evolution of human civilizations that would follow. Today, our unique cognitive ability separates us from all other animals. It was developed thousands of years ago in an epic battle for world supremacy.

 

References: Yuval Noah Harari, Sapiens (Canada: Signal Books, an imprint of McClelland & Stewart, 2014)

The Nature of Things: The Great Human Odyssey, (2015).


 

A Gene Centered View of Natural Selection

Natural selection was Darwin’s term for the mechanism of evolution. In the slow process of evolution nature selects which organisms adapt to their environments successfully (that are most successful at surviving and reproducing). But what is the unit of selection? Is it the species, group, individual or gene? At what level do natural environments shape the evolution of life? Could there be a blending of different units or is one dominant? For example, do species evolve as a consequence of group selection, or do groups evolve as a result of individual selection; or do genes ultimate control the process?

Richard DawkinsThese questions have been debated by biologists and academics for a long time. Richard Dawkins, with the publication of The Selfish Gene, sided on the gene centered camp. The idea of gene selection had been proposed in scientific papers: First by Bill Hamilton in 1964 and then by others, such as John Maynard Smith and Robert Trivers in the early seventies.

Published in 1976, The Selfish Gene placed gene selection into the public sphere by getting beyond the technical aspects of the scientific papers. Dawkins’ book was accessible to a general audience, and has been influential in shaping evolutionary thinking (the 30th anniversary edition was published in 2006). It was, however, controversial as much for its implications as for the gene centered view it supported. According to Dawkins, the book was misinterpreted and used by some groups as biological justification for selfishness in humans; but his intention was to explain how natural selection works, not how people should behave. Dawkins clearly points this out in the first chapter of the book:

“I am not advocating a morality based on evolution. I am saying how things have evolved. I am not saying how we humans morally ought to behave.”

The Metaphor

The title, The Selfish Gene, is a metaphor for how genes propagate. By controlling the traits of organisms, genes influence their own survival. The genes that aid in survival and reproduction are more likely to be copied in future generations. In that sense the genes are selfish and potentially immortal (in the form of replicas), while the bodies that contain them are mortal. Dawkins writes:

“Individuals are not stable things, they are fleeting. Chromosomes too are shuffled into oblivion, like hands of cards soon after they are dealt. But the cards themselves survive the shuffling. The cards are the genes…They are the replicators and we are their survival machines. When we have served our purpose we are cast aside.

genesThe selfish gene metaphor, though powerful, has its limitations; a single gene can’t do very much. Genes interact with each other and combine in complex ways to give rise to physical traits. It is essentially groups of genes that survive (genes that work well together). Therefore, a successful gene can be defined as a portion of genetic material that survives through a number of successive generations.

 Explaining Altruism

“Survival of the fittest,” that is the popular catchphrase for evolution. But an analysis of the mechanisms of evolution requires that we ask: the fittest what? For Darwin, it was the fittest individual that would survive and reproduce. In the middle of the 21rst century, biologists were reintroducing and debating Darwinian ideas. Group selection (the idea that the fittest groups would survive) was gaining popularity. The propagation of the species was the consequence of the fittest groups. However, some biologists were pointing out that group selection was inadequate to explain altruism in animals.

Altruistic Behavior in  Animals

Dawkins is a zoologist by training, and The Selfish Gene focuses mainly on the role of genes in animal behavior. He analyses animal behavior in a variety of species, and points out the correlation between altruistic behavior and relatedness. In other words, the closer the relationship (in terms of shared genes) the more altruism we can expect to see. In this view the genes are at the core of the altruistic behavior, as they aid in the survival of copies of themselves.

zebrasWhen an animal acts altruistically, it appears that the animal is sacrificing some survival need in order to increase the chance another will survive. It does not matter how small the sacrifice is, because a number of small sacrifices can accumulate over time, and also can be reciprocated. The group selection hypothesis interprets altruism as benefiting the group, and in the long run, these groups will be more successful. However, others claimed that selfish individuals would undermine the altruistic group. The selfish individuals within the group would exploit the altruistic system, eventually winning out. The struggle for existence would favor the selfish individuals over the altruistic individuals.

Dawkins argues that seemingly altruistic behaviors can be interpreted differently from a gene centered view. From the gene point of view, the act is still selfish because it aids exact copies of itself (in the form of children, siblings, cousins and so one). Animals are sometimes altruistic because they are programed by their genes to be so. Whether to be selfish or altruistic is a delicate balancing act that is ultimately guided by the genes chances of survival. In addition to helping close relatives, individuals are also dependent on groups. Therefore some consideration for the well-being of the group would likely come into play.

The Social Insects

Perhaps no other example of altruism in animals is as evident as in social insects. This is probably the best example of which a gene centered view of natural selection is adequate. Honey bees, wasps, ants and termites are familiar social insects, and they live in large colonies. The colony functions as a highly organized unit, where each individual has a specific role. Although the roles vary, they can be broken down into two main categories: Carers and bearers. The carers are sterile workers; the bearers are the reproductive females (queens) and reproductive males (drones or kings).

In most species each individual shares in the caring and bearing roles (not necessarily equally). But with social insects it is clearly divided. The sterile workers will devote their lives to providing and protecting the reproducers, even to the point of suicidal actions. This is what we observe when a bee stings a perceived threat to the hive. The bee will almost certainly die.

With an individual selection view, we would not expect suicidal behavior to evolve, because there is nothing to gain for the individual. However, the fact that the workers cannot bear offspring of their own, self-sacrifice for the good of the colony aids in the survival of their genes (shared genes with the reproductive members of the colony). From the gene centered view, what really matters is not just reproducing offspring, but assisting the survival of one’s own genes. There are many strategies in which this can occur (usually a balance of risk and reward). The triggers for the behaviors are surely subconscious. You could say they are controlled by the genes, or call it instincts.

Are Genes Really in Control?

Although there are mountains of evidence that shows life does evolves, determining the level of selection is tricky; it seems like a matter of interpretation. It is not hard to see how each unit of selection would naturally influence the others in the same way (either positively or negatively). For example, if the fittest individual is selected, it will aid its group, species and genes to propagate. We could change the last sentence by randomly shuffling the units (individual, group, species and genes) and it would still hold true.

Maybe natural selection is a complicated process that includes several units of selection. Species, groups, individuals and genes are likely interconnected in ways that are difficult to quantify. I suspect that this issue is not completely resolved among scientists. Nevertheless, I find that the gene centered view is both fascinating and compelling. It is a somewhat counter-intuitive way of looking at evolution, and yet upon closer examination it makes so much sense. Logically, it all hangs together.

 

References: Richard Dawkins, The Selfish Gene (Oxford: Oxford University Press, 30th anniversary edition, 2006).

Beautiful Minds: Richard Dawkins, Published on April 25, 2012. BBC4 https://www.youtube.com/watch?v=C2I8f4lpBLU


 

Darwin’s Theory of Evolution: The Best Idea Ever

Charles darwinCharles Darwin’s 1859 publication, On the Origin of Species, changed the way we look at biology forever. Its central idea, evolution by means of natural selection, explains how all life evolves. No single idea has ever explained so much. It stands apart from most, if not all, scientific discoveries in its outreach and simplicity. As with most great ideas, once grasped, one is inclined to ask: “Why didn’t anyone think of this before?”

Actually, others had similar ideas before Darwin, including fellow naturalist  Alfred Russel Wallace. Wallace had figured out that species evolve through natural selection and sent Darwin his version prior to Darwin’s landmark publication. In 1858 they jointly presented their work to the Linnean Society of London. But ultimately, it was Darwin’s detailed explanation in 1859 that history would recognize.

The Idea

Organisms evolve over time by means of natural selection. Each generation is tested by its environment; the traits that aid an organism to survive and reproduce will tend to be passed on to the next generation. Not necessarily all the time, but often enough or in greater numbers. Traits that are not useful will tend to be discarded when the organism that bears them fails to survive or reproduce.

Through this process survivors are copied with slight random variations, which are then tested many times over. In other words, survivors live longer and usually reproduce more, keeping their survival traits alive in the ensuing generations. Darwin wasn’t the first to suggest that organisms evolve from previous forms, but he provided the mechanism (natural selection).

Why is This Idea so Special?

  • Outreach: Natural selection provides an explanation for how all of life evolves. It accounts for microorganisms, plants, fish, insects, birds, animals and of course humans.
  • Simplicity: As oppose to other notable scientific ideas it can easily be understood by the general public. One does not need any technical science background to grasp the basics of this simple, yet elaborate idea.
  • A confidence boost for science: Before Darwin, few could have predicted that all life on earth could be explained by natural means. Ever since Darwin, few should doubt the power of science to explain just about everything else.
  •  Philosophical implications: Darwin compelled us to take a second look at our place in the world. Long-held beliefs that humans held a privileged position, separate from the other creatures, had to be re-evaluated.
Darwin's Tree of Life

Darwin’s Tree of Life

The Controversy

Darwin delayed the publication of his theory of evolution for about 17 years, because he feared a public backlash. And he was right in assuming that controversy would follow. His chief concern, I can only speculate, was probably religious. Natural selection can easily be viewed as taking god out of the creation business. If nature is shaping all of life, what is god left to do? Despite some criticism, his book drew worldwide interest. Even today evolution still gets some people upset. Why is such a profound idea so difficult for some? Let’s look at possible reasons why:

  • Religious : Evolution contradicts the bible’s account of creation; however, many people seem to have no problem squaring evolution with the bible. They either don’t really know what the bible says or they don’t take it literally. Whereas literal interpreters of the bible clearly see what evolution means for their faith. For them evolution is akin to a fatal blow.
  • Supernatural thinking: If one is inclined to believe that there exists a dimension outside the laws of nature, then anything is possible. Life can then be guided by a supernatural force. If that is the case, evolution is no longer required as an explanation.
  • Evolution is confused with natural selection: I suspect that some people think of evolution as simply gradual change over time. In terms of the cause, they can use their imagination. However, the key insight is the means by which change happens. Evolution is the process and natural selection is the mechanism.
  • Deep time: There is nothing in everyday experience that can prepare us for the time scales involved in evolution. Simple life emerged on earth (in the ocean to be exact) 3.8 billion years ago. And from there spread to all regions of the planet. That’s 38 million centuries for life to evolve to eventually create you and me. Given enough time, minor variations in each generation can result in changes that may be hard for some to grasp.          
  • Sometimes the truth hurts: There is no plan in evolution, no final destination that has to be achieved. Furthermore, human beings don’t hold any privileged position in the tree of life. Darwin described life as a family tree, with different species spreading in all directions. Life could no longer be seen as analogues to a ladder, with humans occupying the top rung.  

A Scientific Idea

Darwin’s idea was much more than a moment of insight. It was a scientific idea, a theory that he developed based on years of experience as a naturalist. As a young man Darwin sailed across the globe on the HMS Beagle. He accompanied Captain Robert FitzRoy on a 5 year journey, where Darwin collected a multitude of natural specimens and fossils. It is on this voyage, from 1831 to 1836, that Darwin gathered extensive evidence for his theory of evolution.

Darwin collected many fossils; some were from ancient sea creatures, which he found in mountainous regions. This was clear evidence that mountains moved over time—that a high altitude had once been under water. From a geological perspective the earth had changed slowing throughout the ages. This principle of gradual change over time was extended to include life forms. If the earth changed, life could also change.

Influential to forming his ideas, Darwin collected bird specimens (finches) from the Galapagos Islands in South America. He noticed that the shape of the finch’s beaks varied depending on the island they came from. Darwin reasoned that the finches all originated from a common ancestor, and had evolved different beaks. The finches had become isolated on separate islands, thus evolving differently to meet the demands of the local food supply.

These and other similar ideas got the wheels in motion for Darwin, showing him that species were not stable, that they can change dramatically over long periods of time. Some of the fossils he unearthed were from extinct species, distant ancestors that resembled species that were still living. He also examined different mammal skeletons and noticed they were all variations of a similar bone structure. Beyond his own ideas, Darwin corresponded with other naturalist around the world through letters, thus gathering piles of information.

It would eventually culminate in the publication of On the Origin of Species. Darwin surely struggled with the implications of his theory, as it would have been radical in Victorian England. Creationism was the overwhelming belief of the time; however, it became clear to Darwin that organisms where not created in their present form. Darwin must have been apprehensive upon the publication of his book. Nevertheless, he was guided by the overwhelming evidence he observed as a scientist. He had to accept what his scientific mind was telling him, regardless of the belief of the day. Darwin’s Theory of Evolution is a great scientific idea, and that is why it still stands today.

 

References: The Genius of Charles Darwin, The Science Foundation, https://www.youtube.com/watch?v=ptV9sNezEvk, Published on Jan 12, 2011.