Life, but not as we know it

species of chameleon, Furcifer labordi, in Madagascar that spends most of its life as an egg. in Madagascar and the American Museum of Natural History in New York, have found a chameleon with a remarkable lifestyle and report the results in the latest issue of the Proceedings of the National Academy of Sciences (published online). Although there are almost limitless theoretical combinations of life-history traits that species may evolve, they lie on a continuum of high reproductive rates, rapid growth and short lifespans at one end of the spectrum, to low reproductive rates, slow growth and long lifespans at the opposite end. Most tetrapods — four-legged vertebrates — have a lifespan that exceeds one year. The researchers examined the life cycle of F. labordi in the arid southwestern part of Madagascar. They found that in November a cohort of chameleons hatch, while no older juveniles or adults are present. These hatchlings grew rapidly, reaching sexual maturity in often less than two months, and reproducing in January and February. " After reproduction, senescence appears, and the active season concludes with population-wide adult death, " the Life, but not as we know it The idea for humans of a life lived mostly in juvenile or larval form appears bizarre. But for many invertebrates that is exactly how it turns out. Mayflies, dragonflies and even butterflies can exist mostly in larval form: the adult sometimes emerging as a brief mating machine. But a larval-oriented lifestyle appears to be rare amongst vertebrates where the progression of development tends to have a more familiar pattern for humans. So it has been a big surprise that researchers have found one Shelled: A new study finds that one species of chameleon, Furcifer labordi in Madagascar, spends most of its life as an egg. (Photo: Chris-topher J. Raxworthy.)