Photo: NASA

Evolution is everywhere — including in the news! That's why each month we publish a new Evo in the News feature on our Understanding Evolution website. This month, we focus on oxygen as an evolutionary constraint. When life began 3.5 billion years ago, all organisms were tiny. Today, earth has some pretty big inhabitants, like the blue whale and the giant sequoia. Learn how the amount of oxygen in the atmosphere opened the door for the evolution of these big organisms. Read the latest Evo in the News story, oxygen as an evolutionary constraint!

Click here to read more Evo in the News stories.

During the Cretaceous, dome-headed pachycephalosaurs roamed through what is now the Hell Creek Formation, covering parts of Montana, Wyoming, and North and South Dakota. But UCMP Curator Mark Goodwin and Museum of the Rockies Curator Jack Horner argue that there were fewer pachycephalosaur species than we thought. Mark and Jack suggest that two species, Dracorex hogwartsia and Stygimoloch spinifer, are actually juveniles and teenagers of the species Pachycephalosaurus wyomingensis. Learn about this modern day dinosaur extinction — read Mark and Jack's paper, published this week in the open access journal PLoS ONE, read the UC Berkeley News press release on the study, and watch this video!

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Photo: Roy Caldwell

Sometimes, the study of basic biology can lead to technological advances, and a recent discovery about the vision of mantis shrimp is a perfect example, providing insight that could help us improve the technology inside DVD players. What is the connection? Circularly polarized light!

You're probably familiar with linearly polarized light. Fishermen often wear polarized sunglasses to reduce the glare from the water and make it easier to see the fish. Typically a ray of light vibrates randomly in all planes, referred to as e-vectors. When light reflects off water at a certain angle, only waves with certain e-vectors are reflected. A linear polarizing filter can be oriented to block those waves, allowing us to see the rest of the light that has passed through the water and is reflected by the fish below. But light can also be circularly polarized, travelling like a corkscrew, twisting either clockwise or counter-clockwise. We can’t see this property of light, but there is one animal that can!

Odontodactylus scyllarus is a stomatopod, or mantis shrimp, living in the Great Barrier Reef. Stomatopods have the most complex eyes in the animal kingdom. About a year ago, UCMP Director and Faculty Curator Roy Caldwell was part of a team of scientists who discovered that when light bounces off the hard exoskeleton of some stomatopods, that light is circularly polarized. What was particularly surprising was that the stomatopods responded to that light — they were capable of seeing circularly polarized light!  What eluded Roy and others was how.

Now colleagues have discovered that the stomatopods don't see the circularly polarized light directly. Special photoreceptor cells in their eyes, called R8 cells, filter/convert the circularly polarized light into linearly polarized light, which can then be sensed by other photoreceptor cells below it. The R8 cell is quite remarkable and might serve as a model for tiny manmade dual-function microsensors.

Manmade filters that convert polarized light are called quarter-wave retarders and are effective only across a very narrow band of wavelengths. The R8 cell (acting like a quarter-wave retarder) can filter light across a wide band of wavelengths, spanning the entire visual spectrum, into the UV spectrum.

There are lots of applications for a highly effective quarter-wave retarder, including DVD players. As DVD technology advances, people are already using circularly polarized light to create 3D movies — one eye sees the clockwise corkscrews of light, and the other eye sees the counter-clockwise corkscrews (Roy received some prototype 3D glasses using this technology and used them to verify that the stomatopods were producing circularly polarized signals!). Digital cameras along with many other optical devices also include quarter-wave retarders in their sensors.

We can learn a lot about optics from the stomatopod eye, and apply this knowledge to new technologies.

Want to learn more about stomatopods? Watch the UCMP video Field notes: Collecting collecting stomatopods on the Great Barrier Reef. And check out Secrets of the Stomatopod: An Underwater Research Adventure.

Image courtesy of the National Geographic Channel

UCMP Assistant Director Mark Goodwin's research on Triceratops is featured on National Geographic Channel's video of the week. Triceratops are named for the three horns that protrude from the skull — and as Mark and his colleague Jack Horner have discovered, those three horns tell a fascinating story about the growth and development, and potentially the behavior, of these dinosaurs.  The National Geographic video is an excerpt from an hour-long television program, Dinosaurs Decoded. Be sure to catch it on the National Geographic Channel on Sunday, October 11 at 9pm, and on Tuesday, October 13 at 9pm.  And check out a preview of the video, along with photos and fun facts, here.

UCMP and the other Berkeley Natural History Museums are well represented on a new exhibit in the Bancroft Library — Darwin and the Evolution of a Theory. We had a special tour of the exhibit last week thanks to UCMP Faculty Curator – and exhibit co-curator – Kevin Padian.

The exhibit is stunning. There are rare books and manuscripts from the Bancroft Library and other campus collections, as well as numerous specimens, including a South American ground sloth fossil from the UCMP, Galapagos tortoise shells and finches from the Museum of Vertebrate Zoology, plant specimens from the Jepson Herbaria… the list goes on. Check out the exhibit's catalog to see more of the specimens included in the exhibit.

Kevin explained that only Berkeley could put on an exhibit like this. Only Berkeley has libraries and natural history museums with the rich collection of books, manuscripts, and specimens required to put on an exhibit of this depth. If you're in the Bay Area, make the trip to the Bancroft Library — the exhibit is open Monday through Friday from 10am – 4pm, and will be on view until December 23, 2009.

Want to learn more about Darwin? Kevin Padian will be part of a panel discussion, "Darwin's Enduring Legacy," on Wednesday, November 4 at 7pm. Look here for more information.

Check out this week's issue of The Economist — it features the work of UCMP Faculty Curator Tony Barnosky. Tony looks at how climate change affects the ecology and distribution of mammals — in the distant past and in the future. The UCMP last blogged about Tony's work here.

This week's big paleo story centers on Ardipithecus ramidus, a species of hominid that lived in the woodlands of Ethiopia, 4.4 million years ago. UCMP Faculty Curator and Human Evolution Research Center (HERC) director Tim White is co-director of the Middle Awash Project, the team of researchers that excavated and studied the fossils. The team includes UCMP Faculty Curator and HERC Associate Faculty member Leslea Hlusko.  Find out more about the discovery:

Tim and his colleagues found a lot of fossil material — over 125 pieces from the skeleton of a single individual (nicknamed Ardi), as well as specimens from nearly three dozen other individuals. The teeth provide clues about the species' social structure, and the pelvis, hand, and foot bones indicate how it may have walked and climbed.

If you're on the Berkeley campus, be sure to check out HERC's exhibit on human evolution, on the second floor of the Valley Life Sciences Building at UC Berkeley. There is a new section of the exhibit about Ardipithecus ramidus.

Photo Credits, clockwise from top left: University of California Irvine, NASA/Goddard Space Flight Center, British Antarctic Survey, Rolando Garcia, NASA, Susan Solomon

Well, hairspray is not really the focus of this article, but the process of science IS, and that explains its connection to the UCMP!

With all of the efforts on our Understanding Evolution website, it did not take long before it became apparent to us that much of the confusion about evolution is linked to confusions about science itself – how it works, what it is, what it is not, and what is not science. In response, UCMP pulled together an astonishing set of advisors and launched a new website that is gaining a lot of attention in the science education community – Understanding Science. The site is extremely rich and contains numerous examples of how science really works.

So back to the hidden hazard of hairspray - Read Ozone depletion: Uncovering the hidden hazard of hairspray, one of the online interactive case studies on the Understanding Science website. This article looks at the work of chemists Mario Molina, F. Sherwood Rowland, and many others and examines how scientific research revealed the global threat posed by chlorofluorocarbons and influenced policy changes. And see how Molina and his colleagues' investigations measure up against the Science Checklist: read The science checklist applied: CFCs and the destruction of the ozone layer.

And while you are there, explore the rest of Understanding Science, an NSF-funded website, and let us know what you think!

I am a graduate student with the UCMP and the Department of Integrative Biology at Berkeley, and I study the biogeography, conservation biology, and microevolution of molluscs. From July through August of 2009, I traveled to nine islands in the Eastern Caribbean looking for Cittarium pica, a large, marine gastropod, or snail. This species has many common names, including West Indian Topshell, burgao, burgos, cingua, magpie shell, wilke, and “whelk”, which is why knowing the scientific name is so important!

Cittarium pica is the largest snail that lives along rocky coasts, reaching a maximum width of 13.6 cm! Since at least the Pliocene, about 5.2 million years ago, the species has lived in the West Indies and along the Caribbean coasts of South and Central Americas. Humans have fished this snail since they first arrived in the region, eating the meat and using the shell for both jewelry and as tools.

Conducting research on the islands of the Caribbean and Northwestern Atlantic is a breathtaking experience, both because of the spectacular views and because it’s hard work! When I found locations on the islands with C. pica populations, I recorded the size and location of individuals within the intertidal zone. I will use this information to assess the fishing pressure on island populations, determine the habitat preferences of the species, and map the distribution of habitat during the Pleistocene. This map can then be used to predict the future distribution of C. pica habitat as the sea level rises due to global warming. During the Pleistocene, sea level fluctuated from ~130m below to ~6m above present day sea level!

At each site, I also collected tissue samples from 25-30 snails (taking them does not fatally harm the animals) to determine the genetic variation of the species on both local and regional scales. These data will provide information on the patterns of larval dispersal within the region and help to identify populations that are at high-risk of local extinction (due to low genetic diversity).

During six weeks of fieldwork, I collected 385 tissue samples from 13 different field sites, conducted ten population surveys, recorded habitat and size information for 2,542 individuals, and collected shells from each site. Whew! I had a busy six weeks! While exploring the rocky coastlines, I also found C. pica fossils in Barbados and several locations with fossil corals. I didn't have a permit to collect fossils, so I'll have to return to those sites in the future.

This trip was the third of four field seasons for my dissertation research. To read more about my summer adventures, please check my research blog.

My 2009 fieldwork was funded by the American Museum of Natural History, Unitas Malacologica, and the Reshetko Family Scholarship Fund.

Jere Lipps retired this year, but the accolades keep coming! Jere has just been awarded the 2010 Raymond C. Moore Medal for Excellence in Paleontology by the SEPM Society for Sedimentary Geology. He receives this medal in recognition of his outstanding contribution to paleontology. Congrats Jere! You can read about his career accomplishments in the most recent UCMP Newsletter. The Raymond C. Moore Medal will be presented to Jere at the SEPM Annual Meeting in New Orleans in April.