Evolution’s Arrow


Does the epic of evolution have a direction?


The universe began around 13.8 billion years ago. Within moments of the birth of our universe, time began. Since then, the universe has been getting bigger and changing.    In certain areas, the universe flows toward more complexity.

Some call this direction “Evolution’s Arrow.”

Note that while the universe clearly has a direction, there is no evidence to suggest any particular destination.

Evidence for Evolution’s Arrow

But people have only had evidence for evolution’s arrow only in the past few hundred years. The sciences of thermodynamics and astronomy have shed light on this.

At the most basic level, the arrow of evolution is caused by the flow of energy.   For more information, check out physicist Eric Chaisson’s article, Energy Rate Density as a Complexity Metric and Evolutionary Driver.

In 1929 Edwin Hubble discovered that our universe is expanding.  Hubble found that light emitted from galaxies shifted toward the red part of the spectrum the more distant that galaxies were.   In 1964, scientists Arno Penzias and Robert Wilson discovered cosmic microwave background (CMB) radiation,  which provided more compelling evidence that the universe had a beginning.

Evolution’s arrow explains why there is such a thing as time, why stars form, why cells cooperate to become organisms, why people congregate into complex societies, and even, why we love.

In what seems like a paradox, the same energy flow that is adding entropy to the universe, can,  at the same time, create areas of local complexity, and thus drive the emerging complexity that we see in life.

It may be that the expansion of the universe causes these local areas of complexity is the expansion of the universe itself.

By showing us where we have come from, Evolution’s arrow shows where we may be going.