Darwin Debugs With Death

_{Johanna Pung link
CC BY-SA 3.0 license}

When a computer program has a bug in it the developer goes into the code, searches for the problem, fixes it, re-compiles that code and then re-runs it.

Nature is not so benign when she debugs her mistakes.

In the mid-1800's Charles Darwin developed his Theory of Evolution and it is one of the greatest achievements in all of science. It was a very conservative and religious time and Darwin knew it was going to be a controversial theory so he kept it a secret for 20 years.

In its simplest form the theory goes as follows, survival of the fittest. Those animals, plants, fungi, bacteria or viruses that are not fit for their local environment die, usually before they get a chance to reproduce and spread their genetic code.

_{Miguel Discart link
CC BY-SA 2.0 license}

In evolutionary theory, the term 'fit' does not always mean strongest (i.e. Brock Lesnar), fastest (i.e. cheetahs) or smartest (i.e. Albert Einstein). It is far more nuanced than that.

For example. mosquitoes are not strong yet they are very abundant across the face of this Earth and they kill more humans than any other animal on this planet (read The Deadliest Animal in the World by Bill Gates). Mosquitoes are incredibly fit for their niche.

Jellyfish are not what anyone would call smart yet they fill the oceans and thrive there with ease. These creatures do not have brains or even what one would call a central nervous system. Instead they have what one would call a nerve net concentration in the epidermis of their bodies. In these ganglions are pacemaker cells that generate and control the swimming actions of these creatures. So, despite being brainless and jelly-like they thrive and are therefore fit for their niche.

Some species reproduce prolifically, generating many offspring that they do not invest any time or energy in (the so-called 'r-selection' strategy). This is debugging at any extremely high rate.

Others such as humans have only a few offspring and invest a lot of time and energy in their offspring (the so-called 'K-selection' strategy). This is debugging at a low rate but one that is potentially more effective.

Whatever the reproduction strategy in any species, there will be offspring with genetic mutations that may affect that individual's ability to survive and thrive in its environment.

_{LadyofHats link
Public domain image.}

There are more ways for things to go wrong than right so usually mutations are detrimental and the individual will die before reproducing.

This is nature debugging a species. Simple, cruel and effective.

Occasionally a mutation is a benefit to an individual such as the first creature to develop rudimentary eye cells ('in the land of the blind, the one-eyed man is king'). Just imagine what it was like to be the first creature to develop sight. Even if it was very poor eyesight compared to ours that creature would have had a field day hunting and eating any of its blind competitors out there.

Eyesight is an amazing advantage so the first creature with that mutation would have gone on to thrive and reproduce and so would its offspring. Eyes would become a thing and more mutations would have improved that sense until you eventually get humans and hawks.

_{Genomics Education Programme link
CC BY 2.0 license}

Closing Words

Life began on Earth over 4 billion years ago. The genetic material may not have even been RNA-based at that time but RNA eventually did develop and later so did the DNA molecule that much of life uses today. These linear molecules encode the programming for a species and if it is good code that individual survives, if it is bad code then it does not.

Over those 4 billion years many species have evolved and disappeared, and by 'disappeared' I mean died. This goes for human species as well, the Neanderthals being the most recent extinction event for a human species.

_{Maxxpixel.net link
CC0 license}

One might therefore wonder if our particular species will also end up being 'debugged' by nature (this topic is very popular source material for many scifi books and movies).

However recent advances in medicine, technology and genomics could mean the end of the cruel debugging by death.

Will future changes in human evolution be a kinder gentler thing more directed and less painful and less deadly? One can only hope.

Thank you for reading my post.