All over the earth , islands are suffering catastrophic diminution in animate being and plant coinage , direct or indirectly from man ’s influence . Strangely , however , in Hawaii , the islands were experiencing local extinctions long before humanity turned up , grant to a subject inNaturethat impute the decline to the older island ' release of realm country .
Hawaii is famous for being created by a volcanic hot spot . Lava work up up the islands directly above the spot , but they started to subside and erode once the spot had moved proportional to the Earth ’s crust . Today only the Big Island is still produce .
" The older islands were all much larger than they are now , and it looks like the flora and fauna occupy up the bionomic outer space tight enough that once the islands began to contract the crowd render tug species to extinction , ” saidProfessor Charles Marshallof the University of California , Berkeley in astatement .
The oldest Hawaiian islands are only a little over 6 million eld old , and of necessity it took clock time for many species to attain such a remote location . Once wench , plants , and insects colonized Kauai , the first island , life jumped chop-chop across minute epithelial duct to New piece of land as they poked out of the sea .
coinage lucky enough to turn over Kauai found a paradise , free from their predators and competitors elsewhere . Colonizing species quickly radiate to fill available niche .
finally , however , these Edens became less idyllic as the inhabitants literally lost the ground from beneath their feet , with the exit of land forcing neighbour to compete for territory .
Estimates of the growth and decline of each of Hawaii ’s islands . Lim and Marshall / Nature
Marshall choose to study Hawaii ’s biological history to test the theory that declines in landmass can have more severe impacts on biological diversity than antecedently think . The discovery that some mammal group had refuse over period of 1000000 of years puzzled biologists , since diversity is expected to increase in the absence seizure of ruinous upshot , and overcrowding was raised as a possible account .
Although Hawaii has no native mammals , the islands ' diverse ages and shrinking size – Maui Nui is now two - third gear modest than it was at its visor – provided a good chance to prove the mind across 14 other group of plants and animals .
The challenge was to figure the preceding variety since Hawaii is for the most part bereft of fossil . Marshall used models of how the coinage ' richness would acquire and correct as the islands ' surface area full and waned , and compare them with what we love of the current richness of each island using the difference in island age to see which modelling describe realism well .
The implications may stretch beyond islands . The paper refers to moist forests and the Eastern Pacific marine tropic as ecosystem that have abridge over millions of year , and may have lose diversity in the process .
I’iwi , or scarlet honeycreepers , have survived despite the diversity of their genus declining as the Hawaiian islands have shrivel , negate the expectation that biological diverseness grows with time . Nate Yuen
