The Discontinuous Mind

Since Charles Darwin and Alfred Russell Wallace independently co-discovered the theory of evolution, the idea that all life evolved from a single common ancestor has been met with considerable resistance throughout the world.  In the past I’ve heard several explanations as to why one of the greatest scientific theories of all time has been met with such resistance and most people seem to converge on two different factors:

1)   Religion – specifically Christianity and Abrahamic religious philosophy

2)   Incredulity – evolution is simply too far-fetched of an idea for most people

These reasons obviously play a role in resistance to the idea of evolution.  Many religious people (especially people who adhere to Christianity, Islam or Judaism) feel as though this theory attempts to explain away their god and their belief system.  Many others are incredulous and simply don’t want to understand it or feel like it is an idea out of a science fiction novel.  However, these explanations for why so many people are resistant to the idea of evolution slightly miss the mark for me.  I think it is a problem that requires a deeper and more universal explanation.

The discontinuous mind

The problem, at its heart, is most likely rooted in “the discontinuous mind”.  The discontinuous mind is the human brains natural proclivity to think that the world can be divided and subdivided into categories (i.e., discontinuously).  By doing this we make great attempts to force the world into qualitative classes.  This is a big conceptual limitation when attempting to understand how evolution occurred and how evolution can explain the diversity of life on our planet.

The discontinuous mind doesn’t just prevent people from understanding evolution.  It pervades almost every facet of human culture and society and although it has practical utility in some cases, it has also produced confusion and has been used to justify discrimination.  A good example of the discontinuous mind at work is our species attempt at racial classification.  In countries that have historically been populated by peoples from diverse backgrounds (e.g., United States of America, South Africa), governments have sought to categorize their population by background.  These classification schemes were used to extend rights and opportunities to people of certain backgrounds and prevent others from acquiring the same rights and opportunities.  However, these governments frequently ran into logistical issues with categorization.  In the United States of America the government established three main racial groups: white, black and native American.  In South Africa, the main racial groups were: white, black and coloured.  Problems arose when governments were forced to categorize people of ‘mixed’ ancestry or when populations arrived that didn’t fit neatly into the established classification scheme.  What were these pro-white governments to do with a ‘white’ person who had a black grand parent?  Were they still to be considered white?  Questions like this arose and caused problems because these governments employed a discontinuous mode of thinking on a world that is continuous.

What does this have to do with resistance to the idea of evolution?

Just as people in the past (and many still today) have conceptualized categories of humans (races) that are static and unchanging throughout time, people have also conceptualized species that are static and unchanging throughout time.  As a result, most people learning about evolution accept that there are evolutionary mechanisms that can bring about changes within species, however they have difficulty understanding how a species can become an entirely new species over time.

When attempting to understand this, someone who thinks discontinuously usually asks the following questions:

How does a species start?

How can there be a first member of a species?

Who was the first human?

How can you go from a single celled organism to a multiple-celled organism to a fish to a lizard to a mammal?

I’ve encountered all of these questions (and many others).  Every time I hear a question like this I realize that this person thinks discontinuously, which means they are going to be enable to understand basic evolutionary theory and will also be unimpressed and confused with my responses to their questions.

“A species does not ‘start’”

“There is no first member of any species.”

“There was no ‘first’ human.”

“Very gradually over billions of years via accumulated advantageous mutations producing a biological ratcheting of complexity.”

The taxonomic classification system is partially to blame for the fact that some people have a hard time understanding that there was no ‘first’ member of any species.  This is because taxonomy arose from the discontinuous thought of the first naturalists who believed that species were unchanging discrete units.  However, modern biologists understand that the taxonomic system does not actually reflect biological reality in its truest form.  It is actually a socially constructed system of knowledge that is an inadequate but necessary conceptual tool used to understand levels of biological diversity.  In this way the discontinuous mind produced a system of knowledge that is now employed by academics that think continuously.

Explaining continuity as key to understanding evolution

In reality, our species, like all other species on the planet evolved gradually and continuously.  The divide between Homo sapiens sapiensHomo rhodesiensis, Homo antecessor, Homo erectus, and Homo ergaster is partly artificial.  There was no first member of any of these species.  There was not one generation when a family of Homo rhodesiensis gave birth to a child that was a member of Homo sapiens sapiens.

So how could this be?

Let’s use a concept employed in the book The Ancestor’s Tale to help conceptualize this difficult fact of evolution: a theoretical time machine.  Today there is one member of our species Homo sapiens sapiens, us.  The reason we are all classified as one species is because of the biological species concept.  With this concept species are members of a population whose fertile sexually mature members can actually or potentially interbreed to produce fertile offspring in nature.  If you were to enter our theoretical time machine and head back say, 500 years, you (a Homo sapiens sapiens) would still be able to interbreed with any other human on the planet.  Although there has been genetic change within our species over the past 500 years, there has not been enough time for mutations to accumulate within our species to prevent successful interbreeding.  Now step back in the time machine and head back 5,000 or even 20,000 years.  Although a great deal of genetic change has still occurred over that time span, you would still be able to produce offspring with a Egyptian pharaoh or a Paleolithic hunter and gatherer (whether you classified that offspring as a ‘hybrid’ would depend on the socially constructed system of knowledge employed to classify organisms).

However, if you were to head back 500kya or 1mya you would be entering a world with different species.  So much time would have elapsed that there would likely be one of two types of genetic barriers between you and Homo rhodesiensis or Homo erectus.  In one scenario, there would be a genetic barrier preventing you from producing fertile offspring with the other human.  There would be sufficient genetic similarity for you and one of these extinct species to produce an offspring, but enough genetic dissimilarity that that offspring would be infertile.  You may be familiar with this phenomenon in the contemporary spatial realm between species like tigers and lions (who produce infertile ligers (or tigrons)), or between species like a donkey and a horse (who produce infertile mules).  In the second scenario, there would be a genetic barrier preventing you from producing any offspring at all.  There would be so much genetic difference that your gametes would no longer be compatible on any level.

Remember, this is a thought experiment to help conceptualize how evolution can produce different species.  Scientists will never be able to test what extinct hominids our species would have been able to interbreed with and what hominids there would have been genetic barriers to interbreeding with.

So, with a slow, gradual accumulation of genetic change evolution can produce millions of species without any of them having a discrete origin.  In other words, we are all intermediates.  Over thousands and hundreds of thousands of years depending on numerous factors a species can turn into a different one, however it will never happen in one generation.  There will never be a situation when one species gives birth to a different species.  In this way, it is best to say that our ability to use language to classify the world is inherently insufficient.  Species exist as a biological concept that is useful (and perhaps necessary) to employ in order to make sense of the diversity of life.  However, in reality it is a discontinuous way to categorize a world that is inherently continuous.

The human mind thinks this way, perhaps innately.  We must learn to think continuously.  A person who teaches evolution or encounters someone who fails to grasp basic evolutionary concepts must first help that person think continuously.  The discontinuous mind, beneath the potential religiosity or incredulity, prevents the idea of evolution to take hold.  People who think discontinuously struggle to make sense of a world that is not static, unchanging and discrete.


About Cadell Last
Hello. I'm probably drinking coffee and reading.

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