Part 6 - Why Are We Here? Why Do Humans Exist?
March 2019
Now that we have travelled through the universe, explored its size and origins, let’s think about our place in it and ask – Why are we here? Why do humans exist?
A “natural” answer to this, to my mind, would be twofold – we are here firstly to eat and so survive and secondly to procreate and carry on the race. All of the species that have ever existed – lions, T Rexes, May flies, dodo s have had these two primal functions so on a very fundamental level that is why we as animals are also here.
However, to understand why we are here on another level, we first need to know how we were formed, what we evolved from and where this organism evolved.
The Burgess Shale is a limestone quarry in Canada. It was formed by a landslide into an ancient sea after the events of the Cambrian explosion, approx. 540 million years ago. The Cambrian explosion refers to the many new species that evolved at that time.
In the Shale are the remnants of that ancient sea that had more varieties of life than today’s modern oceans. The Shale is the best record we have of Cambrian fossils after the Cambrian explosion. Preserved in the Shale are a wide variety of creatures. One of these creatures is our ancestor, the first chordate – it had a backbone and bilateral symetrical body. It is known as Pikaia gracilens and it was about one and a half inches long. Pikaia is the only fossil from the Burgess Shale we have found that is a direct ancestor of humans.
Now think about the Burgess decimation and the odds of Pikaia surviving. If this tiny one and a half inch organism hadn’t survived the Burgess decimation, then everything you see around you today would not be here. By chance, we humans are here today due to the very unlikely survival of Pikaia.
Stephen Jay Gould wrote a whole book on the Burgess Shale and ended his book Wonderful Life: The Burgess Shale and the Nature of History (1989: 323) as follows:
And so, if you wish to ask the question of the ages—why do humans exist?—a major part of that answer, touching those aspects of the issue that science can touch at all, must be: because Pikaia survived the Burgess decimation. This response does not cite a single law of nature; it embodies no statement about predictable evolutionary pathways, no calculation of probabilities based on general rules of anatomy or ecology. The survival of Pikaia was a contingency of “just history.” I do not think that any “higher” answer can be given, and I cannot imagine that any resolution could be more fascinating.
In Part 7 - What is to be Done? We shall draw things to a close and look at what makes a good life and how to live one.
