So Y is not human, but more human like than what birthed it. I'm good with that.
Well, we would call Y a human for all intents and purposes.
Y is not human and it gives birth to Z. Z is also not human, but more human like than Y.
I don't think you get this. Any letter is the same species as the letter before it and after it. The differences between them are not enough to call them a different species. But as you start to get letters further and further apart, then the differences become greater and greater. If the differences are two great, then they can't interbreed and they are different species.
Now Z is human, but Y birthed a human like individual called Z. In your example, Z was birthed more human like but then changed to human.
No. Once an individual is conceived, it can not change its species.
I truly understand what is being taught. I don't understand the coherency. What I'm reading is that non-humans become nearly, if not, infinitesimally more human like until something is born that is so human like that it should be called human because it actually is human.
Pretty much. Look back at my diagram. Humans are the green pixels at the top of the left hand side. If you go down a row of pixels, then the pixels are still green, aren't they? But they are a tiny bit more purple than the top row.
But then you say that now we have arrived at 'human proper', it's parents must also be so close to being human, that while not 'human proper', for all intents and purposes is human. Now, following that backwards, there is never a time when it's parents were not humans.
The problem is that you think of "human" as being a specific thing. There's no such thing as a default human. We're all different. I'm different to you, you are different to any other person. You have to stop thinking of HUMAN as a lightswitch. Lightswitches are on/off things. It's on or it's not. That's easy to understand. But humans are more like colours. We are all green, but some of us have a bit of blue in there. Some of us have a bit of orange, and others might have red. They are the differences that make each of us unique. Evolution is when those colours all change in the same direction throughout the whole population. Evolution is what changes us from being green and slowly, over many generations, changes us to orange.
For the scenario described to be coherent, there must be a birth it which every known parameter that defines human is met and, because it cannot be any other way, it's parents must have at least one parameter that defines human as not met.
That's lightswitch thinking again. Being human is not a Yes/No thing. It's a colour, not a lightswitch. You can say, "Yes, it's green, but there's also some magenta in here as well."
Although it's parents fail at least one parameter that defines humans, we still call them human in spite of them not meeting the full set of parameters that make human, human - OK, I'll accept that.
Sounds like you're starting to see it as a colour thing, not a lightswitch thing.
But, if you keep going back, there will be at least one of two parents that fail at least two parameter that define humans. Maybe we still call them human, but again in spite of them not meeting the full set of parameters.
Yes, that's right, but they don't have to be human. They just need to be the same species as their offspring - which they are.
Continue backwards and eventually there must be a parent that simply cannot be considered human as it fails too many parameters.
That's right. And if you followed your family tree back, from you, to your parent, to their parent, to their parent and so on, all the way back 70 million years, your great great great.... great great grandparent would look something like a shrew. And it would also be in my family tree as well.
Conversely, it's child is considered human because it doesn't fail too many parameters. It must fit the scenario because we birth one at a time, not populations or generations at a time.
No, not quite. The change in any one generation is always going to be very small. It will never be enough for a child to be a different species than the parent.
Thusly, when you use the term human-like, you are saying these creatures fail at least one parameter that defines human, but not enough to be considered other-than-human.
Remember the green rectangle I posted? The right hand side is slightly redder than the left hand side. It fails the parameter to be called the same colour as the left hand side, but you;d still say the right hand side is the same colour.
So, we have generations of very human-like creatures that fail one or more human parameters, but not enough to deem them anything other than human. But you must arrive, going backwards, at a generation that failed enough human parameters that they cannot be deemed human.
Stop thinking about parameters. That's lightswitch thinking. It's not a tick-a-box thing where something either is or isn't.
Because birthing is an individual thing, somewhere in the fuzzy-human-era, a human-like creature had to birth a human.
No. As I;ve said, each generation becomes a tiny bit more human. But each child is the same species as its parents.
Not quite. But you;'re getting there.