cofty wrote:
I find your thinking on this very puzzling JWS.
Any attempt to draw a line would be arbitrary.
How can a mother give birth to a child of a different species?
Can we draw a line between a human and a dog? Or is that too arbitrary? A one cell organism and a human? Or is that line too abitrary?
The question asks about the first human? The first what? Human. We have an idea of that, but what is the exact definition of human? If we are going to find out if there was a first human, we need to know what one is. You are one, I am one. We can agree on that. But that in itself is arbitrary.
We need a specific defintion of what a human is. And the criteria may be arbitrary and include a wide variety of classifications. But once the criteria is decided upon, it eliminates the arbitrary in applying it. And that goes for ANYTHING. Animals, objects, shapes. If you have a definition, you can apply it to a thing. Does it match the definition? Yes or no? And the question is was there a first human. So the term human is a thing and needs a definition.
With a definition, we can compare it to each of our ancestors going backwards. At some point in the past, one of our ancestors didn't fit the definition, if ever so slightly. That's were the previous incarnation ended and humanity began. The last ancestor to fit the definition of human was the first human.
It's all about definitions. Either you fit a definition or you don't. What is so puzzling about that? If you can't define what a human is, then we're all just organisms. Why call a dog a dog or a cat a cat? Why not call everything an animal or an organism?
A mother can give birth to a genetic variation from her own DNA. That's the mechanics of evolution. At some point, that variation fit the definition of human, wheras the parents did not. The change would have been tiny, but just enough to cross that line.
Like with the gradient example. Let's say I define red as an RGB value where Green and Blue are both 0 and Red is a red value of 192-255 (C0-FF). That's an abitrary definition I made up just as biologists could choose what they feel makes up "human". But with definition in hand, I can now use it as a measuring stick. When has the blue changed to red? At the first column that meets the definition for red. Slight change from the pixel before? Sure, but now it meets the definition and the previous one didn't.
Let's say you have an animation of a circle that slowly morphs into a square. When does it become a square? We have a specific definition of a square. A 2D object with 4 sides that comprise 4 lines of equal length and 4 right angles. The circle may start to look like a square as the animation nears completion, but it is not a square until it meets the exact definition.
And BTW, I think the term human would have to encompass variations. We have several races, heights, sizes, hair colors, etc. Just like a red RGB value might be defined by several R values. Still, what meets the definition and what doesn't? If we can't define human then we're the same as everything in that deck of cards.
Hope that clears up the puzzle. And BTW, enjoy reading your posts.