A male Labord’s chameleon is ready for a mate, an urgent quest in a life span of one year. Two-thirds of its life is spent as an egg buried in the sand.

By NATALIE ANGIER

A small, speckled, asparagus-green chameleon of Madagascar holds a world speed record among just about all of the nearly 30,000 different animals equipped with four limbs and a backbone.
Admittedly, it’s not a record many of us would aspire to beat. As researchers recently reported in The Proceedings of the National Academy of Sciences, the entire life span of the Furcifer labordi chameleon - from the moment of conception to development in the egg, hatching, maturation, breeding and right through to its last little lizardly thud to the ground - comes in at barely a year.
That hypercondensed biography, the scientists said, may well make the chameleon the shortest-lived tetrapod on Earth, a creature chronologically more like a butterfly or a sea squirt than like the other reptiles, frogs, birds and mammals with which it is taxonomically bundled.
Equally bizarre, said Christopher J. Raxworthy, an author of the new report, the chameleon spends some two-thirds of its abbreviated existence as an egg buried in sand, with a mere 16 to 20 weeks allocated to all post-hatching affairs.
Moreover, the chameleons operate by a synchronized schedule, hatching, growing, mating and dying at more or less the same times and at the same pace throughout the year. As a result, said Dr. Raxworthy, associate curator of herpetology at the American Museum of Natural History in New York, “if you go into a forest during the dry season, the whole population of chameleons there will be represented by eggs.”
The extremity of F. labordi’s schedule could prove valuable for tracking down genes and other biological factors that promote longevity. The researchers observed that the chameleon is not merely short-lived as a matter of averages. It is an obligate annual species, destined for death after a single spin around the sun, and that stated fate differs markedly from the varying degrees of a long life span found throughout the tetrapod clan.
“There are about a dozen lizard species known to be short-lived, in which a good proportion of individuals die off by a year,” said Kristopher B. Karsten of the zoology department at Oklahoma State University, another author of the report. “But there are always some that make it to the next year, so the species’ maximal longevity is greater than one year.”
That is not the case for our bug-eyed Malagasy friends, which live in the arid, scrubby southwestern region of the giant island. “Once they reach the end of the season,” Dr. Karsten said, “they’re done.”
Assuming a short life is somehow part of the chameleon’s program, researchers might be able to identify the specific genetic or hormonal assassins in lizard cells and find their analogues in human cells.
The new work also underscores the growing use of so-called life history theory to trace the history and contours of life on Earth.
Scientists have determined that many essential features of an animal’s portfolio are linked, among them whether at birth it looks fetal and helpless like a newborn kitten or precocious and competent like a neonatal giraffe; how big the average litter is; the speed with which the animal reaches sexual maturity; the length of time between births; and the pace at which an adult ages.
Try to improve or optimize one of these parameters and you end up paying somewhere else along the line.
Selective pressures in the environment push species toward one life history course or another.
One example is that if you are a species in which the great majority of adults end up being killed by predators or disease, it’s best to invest your resources in breeding early and often and not to bother worrying about long-term needs like a robust DNA repair system.
If you’re a species in which infant and juvenile mortality is comparatively great , the emphasis is often on making the best of adulthood, with delayed maturity and extended life spans. The chameleon is one of the smallest members of its genus, and adults are avidly snacked on by birds and snakes. The local climate is harsh . In addition, the rainy season, which begins in November, when the chameleons hatch en masse, is brief and must be frantically exploited. The lizards immediately start lassoing insects, and they eat so much, Dr. Raxworthy said, “that they practically grow in front of your very eyes.”
By January the chameleons are ready to mate, a nasty, often violent business of males fighting males and females fighting males . Despite their cuteness, Dr. Raxworthy said, “chameleons can be very antisocial, and if you crowd them, they’ll happily fight to the death.”