Scientists uncover factors that shape sea life.
A team of researchers led by Dr. Hudson Pinheiro, postdoctoral ichthyologist at the California Academy of Sciences, have proposed a new conceptual model of island biogeography for marine organisms—a theory that explores how different processes (like sea level fluctuations and geographic isolation) influence marine species diversity around islands.
An unprecedented model of marine evolution The new model suggests that marine species are better dispersers than land-based animals—arriving quickly around inhabitable islands to fill available ocean niches.
This fast action by skilled dispersers leaves no chance for adaptation to cause species to change and fill new niches, as is typically seen over time on terrestrial island habitats.
"In order to crack the forces that shape ocean life around islands, we decided to dig into the evolutionary history of Brazilian reef fishes," says Pinheiro, Academy researcher and member of its Hope for Reefs team.
By tracing the evolutionary history of the reef fishes restricted to this specific chain of seamounts and islands through their DNA, the scientists were able to better understand exactly how island geography, geological history, and sea level fluctuations generally impact the diversity of nearby marine species.
The findings confirm that sea level changes and the locations of exposed seamounts play a critical role in marine evolution over time, mainly by intermittently providing stepping-stones for weak disperser species to colonize island habitats.
Fast-dispersing marine organisms quickly colonize available niches, and we don’t see the same pattern of specialized adaptation over time."
"We knew that MacArthur and Wilson came up with parts of their theory by drawing on restaurant napkins.
Understanding the forces that help shape what allows species to persist in (and adapt to) different environments over time is a useful tool in tailoring conservation work and modeling for the future.