Which evolved first, the human skin, blood, or the human heart?

[RobRit]

I am in a discussion with a theist and he gave me a very weird question indeed.. one that I find a bit moronic and yet a bit interesting.. I then thought about it and I really don't know.. I am not a scientist but am interested in this area.. so if anybody has the slightest ides about this question.. much appreciated.

Which evolved first, the human skin, blood, or the human heart?

Edited August 11, 2016 by RobRit

[Strange]

They all evolved together.

[Phi for All]

Which evolved first, the human skin, blood, or the human heart?

 

Since you specified human skin and heart, but just blood in general, the answer is blood. Blood as we know it developed long before anything you'd call a human existed.

 

But that's the problem here, what you'd call a human. If you try to point and say "This is the first human!", then its parents aren't quite human yet. So didn't the first human's skin, blood, and heart all happen at once?

 

This shows the absurdity of trying to pin evolution down when it comes to speciation. There's a smooth progression that makes it impossible to draw a line. Find a color wheel representing hundreds of thousands of shades in the spectrum, a wheel with no white lines between the colors. When you find one, try to point to where blue becomes violet, or yellow becomes orange. That's what it's like with evolution.

[Strange]

It is certainly true that in early animals, blood developed before the heart. In some organisms the blood (or equivalent fluid) is moved around by the normal movements of the animal, not by a specific organ. But then where do you draw the line between "blood" and other fluids that may have shared some of the functions.

 

And "skin", in the sense of an outer membrane would have come first before any specific circulatory system.

 

But the question as asked seems to imply that humans appeared de novo. There isn't really a sensible answer the the question. It should just be unasked.

[Phi for All]

But the question as asked seems to imply that humans appeared de novo. There isn't really a sensible answer the the question. It should just be unasked.

 

You're right, this is an important point.

 

Trying to answer the question as is lends it relevance it shouldn't have. It leads you down a path that looks well-traveled and brightly lit, that dumps you out under the creepy troll bridge.

[pzkpfw]

Isn't this is another flavour of the "irreducible complexity" argument?

[sethoflagos]

Isn't this is another flavour of the "irreducible complexity" argument?

 

Probably. The intention being to ensnare you in the logical paradox of stating that (for instance) human blood circulated in the veins of a non-human ancestor. And by recursive reasoning, that your non-human ancestor was therefore in fact human. And the house of cards comes tumbling down.

 

It's a sad fact that for certain sections of society, there is little point in responding to such questions with logic and reason. Because your adversary (and it is an adversarial exchange) will not respect those rules.

 

What is being exploited here, as mentioned by Phi for All, is the inherent logical weakness of the taxonomic system in handling a continuum of variation.

 

If the question must be answered, maybe one strategy would be to reply that they were all simultaneously jury-rigged from the corresponding parts of the final missing link. It's a naughty argument. But it sidesteps the paradox, and they deserve no better.

Edited August 12, 2016 by sethoflagos