About 2 to 3 million years ago, a group of spiders let out long silk threads into the wind and set sail, so to speak, across the Pacific Ocean to Hawaii. These spiders were parasites of other spiders, invading their webs, snipping threads to steal insects that had been caught. But there weren't many webs to rob on Hawaii when they arrived. So they expanded their repertoire, looking for other ways to survive by trapping and eating other spiders. A new species evolved from those first spiders, after finding a way to live on rocks. And then another species evolved to live under leaves. And then another. And then 11 more species.

Gold Molokai spider [Credit: George Roderick]

Charles Darwin first noted this phenomenon, called adaptive radiation, in the beaks of finches of the Galapagos Islands. His study of the finches' diversity led to his theory of evolution by natural selection. Yet today, much remains unknown about how adaptive radiation, and thus evolution, actually work. Hawaii is even more of a hotbed for biological diversification than the Galapagos due to its isolation.

In Hawaiian Ariamnes stick spiders, adaptive radiation has resulted in 14 species now living across Hawaii. They share a generally similar body type, but each is a separate species with distinct physical traits. Remarkably, stick spiders with similar traits - yellow and red coloring, for example - live on different Hawaiian islands but aren't each other's closest relatives; they are a rare instance where a physical form has evolved separately on each island, according to a new study by scientists at the University of California, Berkeley. The study shows that evolution has led to a predictable and independently evolved set of similar forms in spiders on each island.

"This very predictable repeated evolution of the same forms is fascinating because it sheds light on how evolution actually happens," said Rosemary Gillespie, professor and Schlinger Chair in Systematic Entomology at UC Berkeley and lead author of the paper. "Such outstanding predictability is rare and is only found in a few other organisms that similarly move around the vegetation."

Ariamnes corniger, a stick spider from East Maui, Hawaiian Archipelago. This white matte ecomorph is cryptic against lichen [Credit: George Roderick]

The study of Ariamnes stick spiders will be published in the journal Current Biology. It was funded by the National Science Foundation and the William M. and Esther G. Schlinger Foundation.

"This study provides insights into a fundamental question about the origins of biodiversity, but also presents a remarkable story that can call attention to the need for conserving nature in all of its forms," said study co-author George Roderick, professor and chair of the Department of Environmental Science Policy and Management at Berkeley.

Hawaii is a chain of islands that formed chronologically, so the scientists were able to study the spiders' adaptive radiations over time as they moved from old to new islands. The oldest island, Kauai, was formed 5 million years ago, followed by Oahu, Molokai, Lanai, Maui and finally the big island of Hawaii, the youngest at less than 1 million years old.

The study found that stick spiders have evolved and differentiated from a single species on the same island. So, spider types on any one island were generally more closely related to very different looking spiders on the same island than to spiders that looked the same on other islands. For instance, a white spider on Oahu is a closer relative to the brown spider on the same island than it is to a white spider on Maui.

An undescribed species of Ariamnes from Kauai, Hawaiian Archipelago. It is an example of the dark ecomorph [Credit: George Roderick]

"You can find these spiders in pretty much every habitat on each island," Gillespie said. "This really detailed and finely tuned repetition of evolution of the same form is really quite uncommon."

The spiders can be grouped into three distinct ecological types, called ecomorphs: A brown one that lives in rocks; a gold one that lives in under leaves, and a white one that's a matte color and lives on lichen.

The analysis of stick spiders mirrors Gillespie's previous discovery in Hawaiian Tetragnatha spiders, another group that shows remarkable adaptive radiation. This group of spiny-legged spiders does not spin a web and has repeatedly evolved similar ecomorphs since its ancestor arrived in Hawaii. That study was featured on the cover of the journal Science in 2004.

The varied habitat types on the Hawaiian Islands, cold and wet areas closely juxtaposed with hot and dry, have provided a rich tapestry of species diversity. The flip side of such extraordinary diversity that evolved in isolation is its vulnerability to change and to invasive species that are now flooding in as a result of human traffic, Gillespie said.

"We need to be able to figure out this diversity and document it and describe what's so special about it, so that people know about it," Gillespie said. "It's being lost and it's a desperate situation."

Source: University of California - Berkeley [March 08, 2018]

The island chain of Hawaii consists of several volcanoes, which are fed by a "hotspot." In geosciences a "hotspot" refers to a phenomenon of columnar shaped streams, which transport hot material from the deep mantle to the surface. Like a blow torch, the material burns through the Earth's crust and forms volcanoes. For a long time, it was assumed that these hotspots are stationary. If the tectonic plate moves across it, a chain of volcanoes evolves, with the youngest volcano at one end, the oldest at the other.

The graph shows the dates of volcanoes of the three volcanic chains in the Pacific and their relative movement over time (left). The location of the three volcanic chains shown in the map (right). The stars mark the youngest end or the active volcanoes today [Credit: Nature Communications, Kevin Konrad et al.]

This concept was initially proposed for the Hawaiian Islands. They are the youngest end of the Hawaiian-Emperor chain that lies beneath the Northwest Pacific. But soon there was doubt over whether hotspots are truly stationary. The biggest contradiction was a striking bend of about 60 degrees in this volcanic chain, which originated 47 million years ago.

"If you try to explain this bend with just a sudden change in the movement of the Pacific Plate, you would expect a significantly different direction of motion at that time relative to adjacent tectonic plates," says Bernhard Steinberger of the GFZ German Research Center for Geosciences. "But we have not found any evidence for that."

Recent studies have suggested that apparently two processes were effective: On the one hand, the Pacific Plate has changed its direction of motion. On the other hand, the Hawaiian hotspot moved relatively quickly southward in the period from 60 to about 50 million years ago -- and then stopped. If this hotspot motion is considered, only a smaller change of Pacific plate motions is needed to explain the volcano chain.

This hypothesis is now supported by work in which Steinberger is also involved. First author Kevin Konrad, Oregon State University in Corvallis, Oregon, and his team have evaluated new rock dating of volcanoes in the Rurutu volcanic chain, including, for example, the Tuvalu volcanic islands in the Western Pacific. Furthermore, they added similar data from the Hawaiian-Emperor chain and the Louisville chain in the Southern Pacific. Based on the geography and the age of volcanoes in these three chains, researchers can look into the geological past and see how the three hotspots have moved relative to each other over millions of years.

The new data published in the journal Nature Communications shows that the relative motion of hotspots under the Rurutu and Louisville is small while the Hawaiian-Emperor hotspot displays strong motion between 60 and 48 million years ago relative to the other two hotspots.

"This makes it very likely that mainly the Hawaii hotspot has moved," says Steinberger. According to his geodynamic modelling the Hawaiian hotspot moved at a rate of several tens of kilometers per million years. Paleomagnetic data support this interpretation, says Steinberger.

"Our models for the motion of the Pacific Plate and the hotspots therein still have some inaccuracies. With more field data and information about the processes deep in the mantle, we hope to explain in more detail how the bend in the Hawaiian-Emperor chain has evolved."

Source: GFZ GeoForschungsZentrum Potsdam, Helmholtz Centre [February 27, 2018]

A strange sight in the sky over Oahu caught the attention of many people overnight. We received several messages via the Report It feature on our website from viewers who saw the lights.

By khon2.com 9-19-17

Mash Hatae says he woke up at around 2:30 a.m. Tuesday to get some water, and the lights in the sky caught his eye.

In the video, you can see two bright lights, and then slowly a third light appears. Hatae says he saw about eight to 10 lights total.
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Every night, the Gemini cloudcam atop Mauna Kea in Hawaii monitor storms approaching some of the world's largest telescopes. It often captures bright bolts of lightning lancing down to the ground below the towering dormant volcano. On July 24th it captured something lancing up:

By spaceweather.com 7-26-17

"This amazing lightning-like phenomenon is known as a Gigantic Jet," says Frankie Lucena of Puerto Rico, who processed the video. "They are related to sprites, but more powerful and easier to see with the naked eye."
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Four men and two women will spend eight months in a dome on a Hawaiian volcano, as part of a human behavior study designed to help NASA prepare astronauts for the journey to Mars.

January 21, 2017 —The eight-month journey to Mars is expected to be arduous, with its cramped conditions, isolation, and monotony. By simulating Mars-like conditions on Earth, NASA hopes to learn how to mitigate the challenges.

By Ellen Powell The Christian Science Monitor 1-21-17

On Thursday, the latest simulation began. Four men and two women – carefully selected from over 700 applicants – moved into a vinyl-coated pod just below the summit of Mauna Loa, the world’s largest active volcano. During their eight-month stay, which mimics the journey to and life on Mars, they will eat primarily freeze-dried foods, have limited personal space, and experience a 20-minute lag in communications (the length of time it takes a message to travel from Mars to Earth).
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