I just finished mowing the back yard today -- an activity which I don't really like but there was a confluence of events that necessitated mowing. The weather is fantastic, the grass is (was) as high as an elephant's eye, and the kids are napping. 'Round the back forty we have two maple trees and a magnolia. The maples were planted in 2002, just before the house was built, and started out around 4-5 feet tall. Apparently one of them just loves the location as it is as high as our two-story house. The other is about half that size. The magnolia I planted in '03 started at four feet (I brought it home in a bucket in the back of the now-extinct Altima) and is now around ten feet. As I was mowing around these trees, admiring the full foliage and soon-to-be-blooming magnolia buds, I was wondering: does a longer gestation/maturity cycle lead to longer, er, longevity? Perhaps put another way: if you take longer to "grow up", will you live longer?

Considering this question for trees is probably not the answer. I would imagine that given a relatively stable environment a tree will live indefinitelya really, really, really long time, given the species. And by stable I mean stable over the lifespan of a tree. So what about the fauna? Why have a lifespan at all? Supposedly cells oxidize over time, breakdown, and the internal biological clock of the cell determines that it is done, and that's that. Cells die and are not replaced, biological processes eventually breakdown, immune systems weaken and the animal/person either dies "naturally" as the cells contributing to life support are too few in number to sustain life, or the animal/person dies as a consequence of the immune system's dysfunction.

I will naturally require some empirical evidence. Off to Google and Wikipedia to look up the numbers.

UPDATE:
Well, I certainly found some interesting things to ponder. I still need some data on timespan for sexual maturity. Courtesy of the Encyclopedia Britannica:

Max Lifespan, in years:
Dog 34
Elephant 57
Horse 62
Human, Medieval England 33
Human, early 20th Century 50
Human, current 77-79 (varies by region)
Giant Tortoise 177

Gestation Period, in days:
Dog 62
Elephant 640
Horse 337
Human 266
Giant Tortoise 120-240

What gives with the tortoise?