Evolution — How Life Changes
We learnt about evolution in school, often accompanied by the familiar picture showing an ape gradually becoming a modern human.
That picture, however, can give the wrong impression.
Evolution does not mean that apes turned into humans. Humans and modern apes share ancient common ancestors and have followed different evolutionary paths over millions of years.
At its simplest, evolution is the gradual change in populations of living organisms across generations.
Individuals within a species naturally have differences. Some of those differences can help an organism survive and reproduce in a particular environment. Over many generations, such characteristics can become more common.
This is the principle of natural selection, famously associated with Charles Darwin.
And evolution is still happening.
Bacteria can evolve resistance to antibiotics. Animals adapt to changing environments. Plants develop characteristics that help them survive particular conditions.
The extraordinary thing is the timescale.
A small change in one generation may seem insignificant. But over thousands or millions of generations, countless small changes can produce enormous differences.
So evolution is not a ladder with one creature climbing towards perfection.
It is more like a vast branching tree of life, with different branches adapting and changing in different directions.
And perhaps the most humbling lesson is this:
We are not separate from the story of life. We are one relatively recent branch on an immensely old tree whose story is still being written.
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