Tag Archives: Darwin

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


 

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Evolution in a Deck of Cards

dnaFor some people the process of evolution is a difficult concept to grasp. For sure, evolution is a counter-intuitive idea. We don’t experience evolution in our daily lives. It only makes sense when we look beyond the surface of things; evolutionary concepts require a long-term view. Perhaps the biggest stumbling block towards understanding evolution is the disconnection between our lives and the evolutionary timeline. If we compared the history of the Earth to the length of a person’s arm, all of human history could be wiped out with a single stroke of a nail file.

Still, despite much scientific evidence for evolution, many people are not convinced. They may look for supernatural explanations for the existence of life, or conclude the question is beyond human understanding. How is it possible that all life evolved from single cell organisms? How did even a single cell evolve? And how did life diversify into millions of species? To get a grasp for evolution we need to shift our attention from the finished product to the process.

Evolution is indeed a process, which is ongoing. And it has no finished product in mind. Evolution can be defined as gradual changes and development over time. However, there is a mechanism that generates those changes, which Darwin called natural selection. Perhaps Darwin’s greatest insight was recognizing the power of natural selection. It is similar to an algorithm, because nature selects positive survival and reproductive traits. It also discards negative survival and reproductive traits. The process is cumulative and continuous from generation to generation. Once the process began improvements to life were inevitable, even though specific outcomes were not guaranteed.

The Card Game

deck-of-cardsAs a thought experiment we can use the analogy of a card game to show how natural selection works. The analogy is not perfect, because there are subtleties in evolution that are more complicated. The exercise is meant to provide a simple analogy for natural selection.

Although it was not known in Darwin’s time, we now understand that life is controlled by genetic information. Essentially, it is genes that are passed on through the generations. In our analogy it is more useful to view the cards as genes, and a hand of cards as a group of genes (or an individual life form). The game has 4 basic ground rules:

1) The deck of cards represents the gene pool: We need to assume multiple decks, because the same genes exist simultaneously in other individuals and are copied many times over. Each card carries information, which may or may not survive each reshuffling. For example, the 5 of spades is one gene and the 10 of harts is another gene.

2) The shuffling symbolizes the generations: Every time the cards are shuffled and handed out, it’s like a new generation. The cards are always being rearranged in different combinations.

3) The players act as natural environments: The players select which cards they want to keep. Just like nature favors different genes in different environments, each player will select different card combinations. In our game some players are playing poker, others cribbage and others bridge. For example, the poker player represents a specific environment, such as an ocean.

4) The goal of the game is to collect the best hand possible: Every player keeps the cards they want, and discards the ones they don’t want. The poker players will collect different card arrangements than the bridge players. But all the cards come from the same card pool. This selection process is done with every deal.

Stable Arrangements

For natural selection to work the process had to work in the primordial period. The creation of life on earth probably did not start in an instant of time. It is more likely that the building blocks (atoms and molecules) were assembling for a long time; nature was favoring stable patterns. Richard Dawkins points out in The Selfish Gene:

“The earliest form of natural selection was simply a selection of stable forms and a rejection of unstable ones.”

microscopic-lifeJust like today, things that last are stable arrangements of atoms (whether living or nonliving). Consequently, life began in a fuzzy period where forms were interacting and assembling. At some point the forms acquired the ability to replicate (with occasional errors). The errors are necessary for evolution; this would be like randomly adding new cards to the deck (like a 15 of diamonds). Eventually, simplicity grew into increased complexity; small patterns grew into larger patterns. This is also what happens with the game of cards.

Exact patterns would be difficult to recognize in the first few hands. Nevertheless, there would still be cards that are more desirable than others. Generally, an ace or a face card is better than a numbered card. But there are exceptions, which depends on the type of game and the combination of cards. With each reshuffling patterns will emerge, where eventually an onlooker could identify the game each player is playing. This is analogous to the time when stable patterns would be recognized and classified as organic life (that’s if someone where watching).

Reshuffling the Deck

We can now see how the process of reshuffling the deck, selecting and discarding the cards would work. It would not take too many hands to achieve almost perfection. Each player would select for their specific game, just like nature selects for its specific environment. All the hands would contain some of the same cards, but in different combinations. Nature mixes the genes in the same way.

cards-in-rowsThe power of natural selection is the continual selection and discarding process, which occurs at unfathomable timescales. Successful genes are kept from generation to generation, random gene mutations are added, and remixed in endless combinations. Only the best of the best survive the process. That is why an after-the-fact view of evolution can be deceiving. Incredible order can emerge without a design and a planned outcome.

Our card game never ends; the players are always looking to make improvements, no matter how small. Many poker players will end up with a Royal Flush (the best possible hand). Bridge hands will end up with every card of the same suit or all aces and face cards. This is where our analogy doesn’t quite measure up. In real life the environments constantly change, which drives evolution to adjust. It’s like occasionally changing some rules to each card game, which will force the players to change their hands.

I hope this thought experiment helps to conceptualize how evolution can accomplish a seemingly daunting task. The basics of natural selection are only a starting point towards understanding evolution. Evolution is a messy process of trial and error, an incalculable amount of trials and errors, which muddies the water. Yet the time involved is critical to the process (more than 3 billion years).

Knowledge of evolution is fundamental towards understanding all life on earth. The life sciences could not progress without it. Our own bodies function as a result of evolution and much of human behavior has evolutionary roots. It has been said that, “Evolution is not something you believe in; either you understand it, or you don’t.”

 

References: Richard Dawkins, The Selfish Gene (Oxford: Oxford University Press, First published 1976, Second edition 1989, 30th anniversary edition 2006).


 

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.