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Rapid Change

February 7, 2016

You’ve seen the headlines.  “A new stage of evolution”, says one article.  “Warmest year on record”, says another.  Both of those are meaningless when it comes to evolution or climate change.

The reason is that both evolution and climate change happen over a very long period of time, longer than a human lifetime.  We can see weather, because it changes every day, and because the changes can be very dramatic.  We can’t see climate at all.  It’s just not visible to us.  How could we ever notice one degree of warming over a hundred years, when we get that much warming in an hour every day.  Sure, climate is the long-term average of weather, but it’s just not tangible to us.  Instead, we have to rely on scientists to tell us how the climate is changing.  They study things like the geologic record, or the carbonate content of shells to determine past temperatures.  We can’t do it ourselves.  We only experience weather, a distraction for us, not climate at all.

Likewise, evolution takes place over a long period of time.  Our human species appeared 200,000 years ago, and has been essentially unchanged since then.  Our species is even relatively young as species go.  Many animal species are much older.  We are not going to see evolutionary change in humans in our lifetime.  We may see it in viruses and bacteria because they can go through thousands of generations in a few weeks.  Again, we have to rely on scientists to tell us how species are evolving.  They study the fossil record to determine the timing of evolution and when a particular species split from an ancestral species, and when it became extinct.  Even though the fossil record is scattered and fragmentary, there is plenty of evidence that evolution is the true pathway for long-term change of species.  This sort of change won’t be visible to us.

Rapid change of multi-cellular creatures, on the other hand, is unlikely to be a result of evolution.  There are several other mechanisms that can result in rapid changes within a limited range.  These are all survival strategies, which creatures can employ when necessary.  Indeed, these strategies may have been formed by evolution, as a way for organisms to get their genes into the next generation.  That is the true goal of evolution.

For humans, communication is supremely important.  Even if it is only spoken communication, we can learn from people who have more experience that we do.  With written communication, we can also learn from our ancestors.  The more lessons we have from other people, the more likely we are to survive.

The phenomenon of epigenetics has been in the news lately.  It’s a mechanism by which the mother of an unborn child can affect the biology of the child.  For example, a mother living in an environment where food is in short supply can give birth to a child who is able to thrive in such an environment.  The advantages are clear.

Genetic diversity is another strategy for rapid change.  Creatures that have a wide range of genetic diversity are more likely to survive under difficult conditions.  They can respond quickly, in a generation or two, to severe threats.  Moths can change their colour to better suit the background colour.  Guppies can change their size to escape being eaten by larger fish.  This all happens because the original stock has a range of colours or sizes to begin with.  The same thing holds for any human population.  We fall on a range between tall and short, muscular and swift runner, or any other criteria that you care to name.  Humans have a fairly wide range of genetic diversity.  Cheetas are an example of animals that have quite a narrow range.  I understand that veterinarians can transplant organs between unrelated cheetas without fear of rejection.  Doctors can’t do this with humans.

Finally, we can change rapidly because of our intelligence.  We can employ analogy, for example, to solve a new problem in the same way that we solved a similar problem.  In computer terms, we have replaced hardware with software.  Hardware takes many generations to change.  Software can be changed in an instant.  That’s a powerful technique for survival of the species.

The problem with anything that involves change over a long period of time is that we can’t observe it in action.  Because of this behavior, it’s easy for us to deny that it’s happening at all.  We deny climate change because we can’t see it.  For the same reason, we deny evolution.  They don’t make sense to us, in our short lifetimes.  We have to open our minds to changes that we can’t observe personally.

 

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