OG study that found a roughly same number of heartbeats was only concerned with averages - https://pubmed.ncbi.nlm.nih.gov/9316546/ . Interestingly humans are outliers with 2-3x the expected number of heartbeats. The way the data was presented always gave me a strong "everything looks linear when plotted on a log scale with big marker" vibe... however it could be totally possible that there is some correlation there.
Maybe evolutionary, there is optimal amount of time for organisms to survive relative to their size. Organism size, in turn, correlates with heart size and heart size correlates with how fast it beats. Probably totally missing the mark, but if it was true, it would be interesting to look into why there are outliers.
Anywho, I find it humorous to think about a battery theory car analogy - "every car has a preset number of miles and maintenance would decrease usable lifespan of the car because you need to drive to the mechanic".
Maybe evolutionary, there is optimal amount of time for organisms to survive relative to their size. Organism size, in turn, correlates with heart size and heart size correlates with how fast it beats. Probably totally missing the mark, but if it was true, it would be interesting to look into why there are outliers.
Anywho, I find it humorous to think about a battery theory car analogy - "every car has a preset number of miles and maintenance would decrease usable lifespan of the car because you need to drive to the mechanic".