Scientists are investigating the remarkable longevity of certain tropical butterfly species, which can live for months rather than weeks, in hopes of understanding the evolutionary mechanisms behind extended lifespans that could hold relevance for human aging.
Extended Adulthood in Heliconius
Butterflies from the Heliconius genus, found in South and Central American rainforests, display a wide range of adult lifespans. While some species, like the Dione juno, live for about 14 days, others, such as Heliconius hewitsoni, can survive for up to 348 days, nearly 25 times longer. The study, published in Nature Communications, notes that other Heliconius species endure between 106 to 277 days. Previously, scientists speculated that this extended adulthood might be linked to an enhanced diet, going beyond the carbohydrate-rich nectar typically consumed by most butterflies.
Dr. Jessica Foley, the study’s lead author and a postdoctoral scholar at Tufts University’s Jean Mayer USDA Human Nutrition Research Center on Aging, was inspired by these differences to explore the Heliconius genus. Foley highlighted the vast lifespan variations across the animal kingdom and expressed interest in the evolutionary basis of these differences, suggesting they might offer insights into healthy aging for humans.
Diet and Evolved Mechanisms
The research team combined data from commercial butterfly facilities, mark-and-recapture studies, and controlled experiments to analyze lifespan and aging patterns within the Heliconius genus. A key focus was understanding the role of pollen, which some Heliconius species consume as adults, unlike most butterflies that rely solely on nectar.
While typical adult butterflies feed on nectar for carbohydrates and die after depleting these resources, many Heliconius species have adapted to feed on pollen. Pollen provides lipids and amino acids, which are crucial for reproduction and energy storage, and may also boost immunity. The study investigated whether removing pollen from the diet would shorten their lifespans.
Of the 28 Heliconius species studied, only six did not feed on pollen and lived between 14 to 98 days. However, even when pollen was withheld from pollen-feeding species, they still lived significantly longer than their non-pollen-feeding relatives. This observation led researchers to suspect that beyond diet, these butterflies have evolved specific anti-aging mechanisms.
Measuring Age-Related Decline
To assess physiological aging, the researchers developed a device called “The Pullinator.” This apparatus, a sandpaper-lined perch attached to a balance scale, measured the grip strength of older butterflies. The Heliconius hecale, capable of living up to 277 days, showed minimal age-related decline in grip strength. In contrast, the closely related Dryas iulia, which does not feed on pollen and lives for 98 days, exhibited signs of age-related decline.
The findings indicate that many pollen-feeding Heliconius species not only live longer but also age more slowly. Pollen-derived amino acids also appear to support continuous egg production in adult females, extending their reproductive lifespan. Crucially, the fact that Heliconius butterflies maintained longevity even when deprived of pollen suggests they possess evolved mechanisms for living longer, independent of their diet.
“We show that these butterflies do have evolved mechanisms of longevity, and that they also seem to have evolved a delayed physiological decline, making them excellent new models for studying the mechanisms allowing for long life,” Foley stated. “However, we do not yet know what these mechanisms are.”
Other researchers, like Dr. Jaret C. Daniels of the Florida Museum of Natural History, view Heliconius as a valuable model organism for studying longevity and potential adaptations that could slow aging, with possible applications for understanding human longevity.
Norman Pearlstine is the Chief Editor of News Raise and focuses on Business news. His responsibility is to oversee the editorial content including business, commodities, personal investments and the stock market.
