Study to Focus on Hawaii’s Unique Insects and Spiders

A team of scientists say Hawaii’s geology, geography and insects provide a unique opportunity for the study of evolution.

University of Hawaii at Hilo biology professor Don Price will be among the researchers taking a look at the biodiversity of Hawaii’s insects and spiders, and how they came to settle in the various islands.

The $2 million project spearheaded by the University of California, Berkeley will study the way the native arthropods have evolved over millions of years.

University of Hawaii at Hilo biology professor Don Price. Courtesy photo.

Price said Hawaii is ideal for the study. It is remote, which means its wildlife developed in isolation, which led to unique species. And it is a fairly small land area, which makes it easier to study.

Also, the volcanic islands developed in stages, providing niches and a timetable for the development of new species.

And nowhere is that more evident than on the still-growing Big Island, where the study will begin.

Price said the first forests that developed on the Kohala volcano a half-million or so years ago were likely colonized by species from Maui Nui, the land mass that would become the islands of Maui, Molokai, Lanai and Kahoolawe.

Many millennia after Kohala, Mauna Kea rose from the sea, providing another new opportunity for the expansion of life. It was followed by Hualalai, Mauna Loa and Kilauea, each providing an opportunity for new species to develop.

“In time they become a community,” Price said.

A prime example of that development is the fruit fly drosophila (droh-SOF-uh-luh). Price said in Hawaii, that genus has developed into 800 different species, representing 25% of all drosophila species in the world.

That genetic diversity, which includes unique courtship behaviors scientists previously nicknamed “dirty dancing,” has made the insect a prime candidate for evolutionary studies.

One species of spider on the Big Island (Tetragnatha anuenue) shows an extraordinary diversity of color as well as genetic diversity, which scientists believe serves as the raw material for the formation of new species. Photos by Rosemary Gillespie, UC Berkeley. (Click collage to enlarge.)

The study will also look to trace the origins of Hawaii’s spiders, and how they diversified.

The researchers will collect DNA to look for genetic markers that show how the various species have adapted to their individual environments.

According to Rosemary Gillespie, director of UC Berkeley’s Essig Museum of Entomology and one of the university’s principal investigators in the study, one of the questions researchers hope to answer is how such diversity resulted from what is essentially a genetic bottleneck.

“One of the most puzzling features of the high diversity of species on remote islands is that these species almost certainly arose from one or very few colonizers,” Gillespie said in a statement issued by the university.

“We are trying to see which animals get there first — something that eats plants or animals, dead or alive, for example — and whether the pattern of arrival and the community thus formed is predictable,” Gillespie said. “Then we can see how the community of organisms thus assembled might allow its members to diversify.”

Price said the study will bring together scientists from a variety of disciplines. Some will be population geneticists, who study the diversity of species, while others are evolutionary biologists like Price who look at how the species have adapted.

Yet others are specialists in energy and resources who will explore how interactions between species change as a community develops.

In addition to Price, other collaborators on the project include scientists from Cornell University; the University of Maryland, College Park; and the British Museum in London.

The study will examine how Hawaii’s unique wildlife has evolved. Photo courtesy of Don Price.

The project is funded by the National Science Foundation’s Dimensions of Biodiversity program. It also ties into the Berkeley Initiative on Global Change Biology, which looks at how biodiversity has responded to past environmental changes with an eye toward predicting the consequences of future environmental change.