Let’s imagine that organs can be perfectly grown in a lab and installed into a body without any chance of rejection or other complications usually associated with organ transplant.
You, a perfectly healthy adult human, go to the doctor and have them put a second heart in your chest that is connected to the circulatory system with your original heart.
What would be the effects of this? Could it even be done in this hypothetical situation at all?
My concern would be complexity.
More points to fail, and I’m not sure that it reduces single-points of failure much.
I understand the concern, but I see it as more redundancy, like kidneys. If 1 heart gives out, you have a spare, and considering that we only have 1 that can do its job for 100+ years i dont see complexity as being an issue.
Also Im just here to advocate the theoretical that you could have 2 hearts with no issues, rather than it being something completely impossible.
The problem comes in, what happens when a heart fails? depending on the failure mode, it may represent a total blockage, in which case you’re toast. You might be able to survive with one heart if you had two, but if you add a second heart, then your other heart will likely be less developed unable to perform at whatever peak performance you had before.
If your method of redundancy adds more single points of failures. Also, the addition of a second heart poses the problem of keeping them coordinated; with all sorts of problems coming up if they get out of sync. adding redundancy will always add complexity, especially as you work to remove single points of failure and try not to add extra. In some systems, it’s just unwise to add redundency because the complexity means it’s more likely to fail.
Famously, Charles Lindbergh, for example, opted for a single reliable engine over two engines. It kinda flew in the face at the time. But then he was the first to go from NY to Paris in a non stop flight, in the Spirit of St Louis. Similarly, we can expect, if there was in fact some significant advantage, that then, everybody would be doing it. Or, at least, lots.
Keep in mind, cephalopods have 3 hearts- 2 are single chamgered things that boost blood over gills, and the 3rd provides bloodflow to the rest of the body. Hagfish have one chambered heart and several boster things that aren’t really much of a heart. Earthworms aren’t possessed of true hearts (they lack chambers and valves,) cochroaches and leaches also don’t have true hearts.
But where we see 4 chambered hearts (birds, mammals, and crocodillian reptiles,) they all only have 1. That should tell you something.
I agree with what youre saying completely, Im just saying i theoretically could see how you could live with 2 hearts, not the efficiencies, intricacies, or failures of having 2.