How have changing sea-levels influenced evolution on the Galapagos Islands?

May 06, 2014

The Galapagos Islands have an iconic status in the history of evolutionary study, now new research shows that the islands' own geological past may have influenced the evolution of the chain's native species.

Writing in the Journal of Biogeography, Jason Ali and Jonathan Aitchison explore how fluctuating sea-level changes over thousands of years impacted the island chain's ecology. They estimate that when the sea retreated, most recently 20,000 years ago, the water would have been 144m below its current level.

As a result, Santa Cruz, the island in the center of the archipelago, would have expanded, enveloping many of the smaller while creating a series of shallow 'land bridges' between the volcanic outcroppings. Such bridges explain the range and diversity of the islands' species, such as snakes, geckos and iguanas, which appear landlocked to modern eyes.

"As soon as I saw that that half the islands in the archipelago were sat on a single, shallow, submarine platform, I realized that the implications for biology could be significant," said Dr. Ali. "My geological knowledge told me that sea-level falls must have regularly re-connected the islands, and that this must have profoundly shaped the landlocked biota's distribution, and very likely its composition."


Explore further: Dynamic atolls give hope that Pacific Islands can defy sea rise

More information: Jason R. Ali, Jonathan C. Aitchison,'Exploring the combined role of eustasy and oceanic island thermal subsidence in shaping biodiversity on the Galápagos,' Journal of Biogeography,DOI: 10.1111/jbi.12313

add to favorites email to friend print save as pdf

Related Stories

French islands under threat from rising sea levels

Sep 18, 2013

By the year 2100, global warming will have caused sea levels to rise by 1 to 3 meters. This will strongly affect islands, their flora, fauna and inhabitants. A team of researchers from the Ecologie, systématique et évolution ...

Iconic Galapagos bird suffering population decline

Apr 30, 2014

One of the iconic birds of the Galapagos Islands, the blue-footed booby, has suffered a sharp population decline, authorities in the Ecuadoran archipelago said Wednesday, blaming overfishing.

Moth lineage provides a key to species diversification

Mar 28, 2014

To many, moths are just the dull relatives of butterflies that often startle us in the dark. But for UH Mānoa Junior Researcher Dr. William Haines, former Junior Researcher Dr. Patrick Schmitz and Professor ...

Recommended for you

Dolphin hunting season kicks off in Japan

2 hours ago

The controversial six-month dolphin hunting season began on Monday in the infamous town of Taiji, but bad weather would delay any killing, a local official told AFP.

User comments : 0