Earth's richest concentrations of marine life have shifted over time, cropping up where tectonic plates collide and the climate is friendliest to life, new research suggests.
Today, seas surrounding Indonesia are a hotbed for marine life. But eons ago, the Mediterranean and the Arabian seas were just as rich, scientists report in tomorrow's issue of the journal Science.
In their study, researchers compared genetic data with fossil records to discover at least three marine hot spots in the past 50 million years. The zones have migrated over time, so that almost half Earth's surface has hosted them at various periods.
"There are always hot spots, but they are always moving," said Willem Renema, a geologist at the National Museum of Natural History in the Netherlands, who led the study.
"[Hot spots] are dynamic entities. You can predict the location by looking at climate and tectonics."
Warm, Shallow Seas
Renema and his colleagues launched their investigation to explain rich veins in the marine fossil record.
Climate alone wasn't an exact match, Renema said: "The areas that are most diverse are not the warmest areas."
But when climate was considered alongside large-scale geologic processes, the fossil and genetic markers of marine biodiversity synched up.
Hot Spot Life Cycles
A present-day hot spot for marine life is the "coral triangle," a border area between the Indian and West Pacific oceans that is generally defined to include the coastal waters of Malaysia, the Philippines, and Papua New Guinea.
(See a map of the region.)
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