And when I tag this thing as a “point refuted a thousand times,” I pretty literally mean that. Here’s a quote from 2004 making essentially the same argument.
And now for the equally tired counterargument:
Dawkins muses: “Living things are not designed, but Darwinian natural selection licenses a version of the design stance for them [oh, that’s very generous of it!]. We get a short cut [one has to pick up that he is being sarcastic here] to understanding the heart if we assume that it is ‘designed’ to pump blood.”
That’s not sarcasm. That’s the result of human minds being highly tuned to anthropomorphize. Perhaps human intelligence got the way it was because of an arm’s race with other humans, which would imply that most of the new brain equipment is purpose-built for thinking about other humans? Or maybe it’s just that living in a society means that the empathy center of the brain gets the most exercise? I’m not sure, and I know even among evolutionary biologists it can be controversial.
So, au contraire, the heart just by chance grew to be a pump – for no purpose whatsoever, mind you – because, well, “accidents happen?” Why didn’t it “accidentally” grow to be, say, a waste-disposal site, a pulley to hoist objects upward, a bone-assembly plant, a poison-producer, a … (fill in the blank)?
If it had evolved to act as a pulley instead of a pump, and it had worked, you’d be asking “why didn’t it ‘accidentally’ grow to be, say, a pump.” If it had evolved to act as a pulley, and it didn’t work, our bloodline would have died off and the pump-hearted people take their place.
Seriously, man. It’s Evolution By Natural Selection. Explaining why humans don’t exist with non-viable organs is the easy part. The hard part is explaining the mutually-dependent body parts.
Fancy that: it just so happened to coordinate its development with that of blood! And in cooperation with an enormously complex circulatory system of a myriad of blood vessels needed to make blood useful for tens of trillions of cells, missing none!
There are animals with circulatory systems that don’t rely on a heart or other pumping system. They’re small, because you can’t get nutrients through a large body very efficiently by relying entirely on dissolving them in a liquid and letting them diffuse, but they exist.
I should point out that, if you examine animals like that, you’ll find their system is equally refined to ours. This is not a coincidence — there is no such thing as a “less evolved” creature outside of fossils, since all species alive today date back to a common ancestor and are therefore equally old — but it still serves as an existential proof that animals with no heart to move their blood are viable.
And miraculously timed to receive electrical signals from some clump of gray stuff in the head to make the fool thing function on a timed cycle of beating!
That’s just not true. The human heart does not rely on the brain to continue beating. The brain can ask it to speed up or slow down, but the heart has its own pacemaker.
And choreographed with these things called lungs that provide oxygen and remove carbon dioxide to make blood relevant at all!
Modified version of a fish’s swim bladder. So-called lungfish, that use these sacs for breathing in addition to controlling their buoyancy, also exist. There’s a nice book, Your Inner Fish, about all the vestigial carryovers that connect humans with other animals.
Interesting how the heart can autonomously operate, but the lungs can’t? I bet it might have something to do with fish possessing hearts, while swim bladders would obviously have started out as voluntary muscles!
And a handy stomach to supply nutrients that blood can then transport to all parts of the body!
And you think these all had to emerge, formed exactly like they are in humans, for any organism to be viable?
And a shell of skin to keep that blood from squirting out into space!
You’re not even attempting to think about a reasonable order of events where most of these features evolved, independently, and only came to become interdependent later. Seriously, you aren’t going to overturn relativity with a racecar-on-a-lightspeed-train idea, and you aren’t going to overturn evolutionary biology with yet another tired variant of the Mousetrap Argument.
Skin seems like it could be useful, even in an animal with no blood, to allow it to keep bad stuff out. Like sea sponges; they don’t have blood, but they have outer and inner layers anyway.