Island formation promotes penguin diversity

Feb. 6 (UPI) -- Want more penguin species? Build an island.

New research published in the journal Molecular Biology and Evolution suggests the formation of islands spurs penguin speciation, boosting diversity.

Of course, Darwin was the first to make the connection between the isolation of island life, evolution and speciation. On the different islands of the Galapagos Archipelago, Darwin noted differences among the finches, turtles and lizards.

Scientists think a similar dynamic fueled the diversity of modern penguins, despite the fact that the birds spend the majority of their lives at sea.

"We propose that this diversification pulse was tied to the emergence of islands, which created new opportunities for isolation and speciation," Theresa Cole, researcher at the University of Otago in New Zealand, said in a news release.

Cole and her colleagues surveyed the modern penguin taxa using skin, bone and blood samples. Researchers also analyzed the remains of penguins housed in a variety of museum collections. Genomic sequencing helped scientists better understand the timing of penguin diversification.

The analysis of the branching of the penguin family tree and the emergence of islands over the last 5 million years revealed a strong link between the two phenomena. Researchers also determined that island-driven speciation can help explain two recent human-caused extinctions.

"Our findings suggest that these taxa were extirpated shortly after human settlement on the Chatham Islands," said Cole. "These findings thus potentially represent important new examples of human-driven, Holocene extinction in the Pacific."

Islands drive specialization and speciation, but they also make it harder for animals to relocate and adapt if and when the environment suddenly changes -- like the arrival of penguin-hunting humans.