Why do some animals live much shorter lifespans than humans and others much longer? What determines the lifespan on an animal?
In: 58
Its not a straightforward question as every animal has a maximum possible lifespan determined primarily by its ability to regenerate cells, and this in turn in governed by telomeres, their length and the presence or not of telomerase (this is the genetics answer).
Other than that, maximum lifespan is limited by how the animal functions everyday and what factors might degrade its cells and/or cause new cells to be created in healing and replacement.
Factors that shorten life could include hormonal stress, food source, physical stress, toxins, or a whole lot of other factors. Basically anything that makes an animal perform above its resting state or directly attacks it; and buses… they really shorten life expectancy.
Edit. many wrong comments on this question. You cannot associate size with life expectancy, and while metabolism can play a part it is by no means definitive.
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