According to one estimate, about 108 billion humans have ever lived. The exact number is probably unknowable. However, one thing we can know with certainty is that all of them have been fallible. So far they have also all been mortal. And with billions of years of life behind us, we have enough data to indicate that pattern is likely to continue, unless there is an exception alive out there today (I doubt it).
In any case, the fallible humans have a number of consistent flaws and frailties in our biology — senescence, bad backs, myopia, etc. We should expect evolved beings to have built-in limitations in their biology. My favorite quote explaining why this should be comes from Matt Cartmill, who once said: “Evolution doesn’t act to yield perfection. It acts to yield function.”
Over at Scientific American, Kate Wong compiled a listof some of the most compelling discoveries in human evolution from 2013. I won’t rehash her entire list here, but the ones that will stick with me for a while include the variation found among the Dmanisi hominins, probably all within the same species. The other is the genetic evidence for interbreeding between Neanderthals, Denisovans, and other extinct humans. Fascinating.
With another contentious election now behind us, I’ve been thinking about this famous, lengthy quote from Bertrand Russell. In an interview from 1959, he spoke of the need for people to find common ground and to make an honest effort at seeking truth, even when we don’t like what the truth is.
I should like to say two things, one intellectual and one moral.
The intellectual thing I should want to say to them is this: When you are studying any matter, or considering any philosophy, ask yourself only what are the facts and what is the truth that the facts bear out. Never let yourself be diverted either by what you wish to believe, or by what you think would have beneficent social effects if it were believed. But look only, and solely, at what are the facts. That is the intellectual thing that I should wish to say.
The moral thing I should wish to say to them is very simple. I should say: Love is wise. Hatred is foolish. In this world which is getting more and more closely interconnected, we have to learn to tolerate each other. We have to learn to put up with the fact that some people say things that we don’t like. We can only live together in that way — and if we are to live together and not die together, we must learn a kind of charity and a kind of tolerance, which is absolutely vital to the continuation of human life on this planet.