WEALTH begets wealth 鈥� at least when it comes to island ecosystems.
Like Darwin鈥檚 finches in the Galapagos, plants and animals that reach remote islands are often able to occupy vacant ecological niches and develop into new species. But the process forms a virtuous circle, with new species arising faster on the most biodiverse islands, according to Brent Emerson and Niclas Kolm at the UK鈥檚 University of East Anglia in Norwich.
They counted arthropod and flowering plant species on the Canary and Hawaiian islands and calculated the proportion of endemic species 鈥� those found nowhere else. The number of endemics is a good indicator of how fast new species have developed on the island. Emerson and Kolm found that islands with the richest variety of species for their size also had the largest proportion of unique species (Nature, vol 434, p 1015). Both volcanic archipelagos lie far from a mainland source of potential colonists.
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The study has implications for conservation. 鈥淚f the long-term goal is to maintain species diversity then you have to maintain a system that can also generate diversity,鈥� says Emerson. 鈥淭he more species that you lose the more you reduce the potential to create new species in the future.鈥�
