Ming Ming died this month at 34, a ripe age for a panda. But why do some species live longer than others? MARIE BORANexplains
MING MING, the world’s oldest panda, died this month at the age of 34. She lived 12 years longer than her average fellow panda. But why is 34 a ripe old age for some species and not for others?
Animals, it turns out, follow one of two paths. “One option is to live fast, die young and have lots of children,” says Dr Nicola Marples, who teaches zoology at Trinity College Dublin. “The second is to have a few children, live long enough to look after them, and reach old age.”
All mammals’ hearts are thought to be good for about a billion beats: as an elephant’s heart beats 28 times a minute and a mouse’s beats 500 times, elephants live far longer than mice.
This does not necessarily mean that a rapid heartbeat will make you die younger, but regular exercise leads to a longer, healthier life and naturally lowers the heart rate. Improvements in lifestyle and diet also play important parts in longevity: globally, humans now live for about 67 years.
Ultimately, though, our underlying metabolic rate – the rate at which cells divide – determines our destinies, says Marples. Over time, as cells divide more, errors occur in the genetic code, and the body begins to fall apart – which leads, eventually, to death.
