Why Whales? What Sends Land Animals Back to Sea

Whales, the largest animals we know of that have lived on Earth, are descended from deer-like creatures that splashed around in creeks about 50 million years ago. It’s not just the mammals that went back to sea: Birds and reptiles also re-colonized the oceans after living on land.

Blue whale

A blue whale off the coast of Southern California. Photo by D Ramey Logan, via Wikipedia.

What drives species to move into such a different habitat? One prevailing idea is that following mass extinction events, surviving species occupy the habitats left empty in a burst of biological creativity. But there could be other, less dramatic reasons: perhaps there were too many predators on land, or an abundance of resources in marine environments.

Steps Towards Making a Hydrogen Fuel Enzyme

Science generally gets reported as if it happens in big leaps, but in reality most of the time science progresses in small but satisfying steps. One example of this is another step in a story I have followed for several years from Professor David Britt’s lab in the UC Davis Department of Chemistry, published April 9 in the journal Nature Chemistry.

David Britt’s laboratory at the UC Davis Department of Chemistry uses advance techniques to study how enzymes that can produce hydrogen are assembled.

Model of Blobs in Earth’s Interior Explains Unusual Pacific Volcanism

By Becky Oskin

Deep inside the Earth are two huge blobs of dense rock splayed across the core-mantle boundary. One of the underground structures sits under the South Pacific and the other is underneath Africa.

Plumes rising from these deep masses feed some of the planet’s most spectacular volcanic island chains, such as the Hawaiian Islands. Because the volcanoes fed by the plumes have an unusual chemical fingerprint, scientists think the blobs are made of rock different from the rest of Earth’s mantle. Scientists also know these continent-size structures are not like typical mantle rock because seismic waves pass through the structures more slowly than in the surrounding mantle. This observation gives the two large blobs their jargony name — “large low shear velocity provinces” or LLSVPs.

“Hey, Alexa…” Students Compete for Amazon’s AI Prize

By Bonnie Dickson

A UC Davis student team is one of eight teams worldwide  recently selected to compete in Amazon’s 2018 Alexa Prize Challenge – an artificial intelligence competition to advance the technology behind the company’s popular social bot.

Team Gunrock includes 12 graduate students and two undergraduate students with diverse, interdisciplinary backgrounds related to artificial intelligence. Advised by Zhou Yu, an assistant professor of computer science in the College of Engineering, the team has received a $250,000 research stipend, Alexa-enabled devices and support from Amazon’s web services team to assist with their development efforts during the competition. The team also has access to Alexa’s application programming interfaces as well as additional tools, data and support from Amazon’s Alexa team.

Making an Impact in Research: Advice from Experience, Pitch Slams from Grad Students

Sometimes there’s just too much going on at UC Davis. Today, you could hear from two groups of researchers at very different points in their careers, looking to make an impact and talking about how to have an impact with research.

Today’s UC Davis Research Expo was put on by the Office of Research with the theme “Pathways to Impact”. This afternoon, the Office of Graduate Studies hosted the final UC Davis round of the Grad Slam competition.

Panel discussion

A panel of accomplished UC Davis scientists (and one classicist) discuss how to make an impact with your research at the UC Davis Research Expo, April 5, 2018.

Podcast: Plant Biochemist is Top Teacher

In this episode of the Three Minute Egghead podcast, meet Judy Callis, professor of molecular and cellular biology, who has just received the UC Davis Prize for Undergraduate Teaching and Scholarly Achievement.

Professor Judy Callis studies the ubiquitin system in plants. She is recipient of the 2018 UC Davis Prize for Undergraduate Teaching and Scholarly Achievement.

Callis teaches biochemistry and her lab studies the ubiquitin system in plants. Once thought to be a way to tag proteins inside cells for “garbage disposal,” ubiquitin turns out to have a ubiquitous role in regulating metabolism.

Listen: https://soundcloud.com/andy-fell/plant-biochemist-is-uc-davis-top-teacher

With Giant Lens, Astronomers Find a Single Star Across Half the Universe

Through a lucky quirk of nature, astronomers have used the Hubble Space Telescope to view a single star halfway across the universe. Nine billion light years from Earth, the giant blue-white star, nicknamed “Icarus” by the team, is by far the most distant individual star ever seen.

Distant star image

Icarus is the farthest individual star ever seen. It is only visible because it is magnified by the gravity of a massive galaxy cluster, located about 5 billion light-years from Earth. The panels at right show the view in 2011, without Icarus visible, and the star’s brightening in 2016. (Hubble/STScI)

Study That Cast Doubt on Mouse CRISPR-Cas9 Retracted

A study that cast doubt on the usefulness of CRISPR-Cas9 “gene editing” technology to introduce genetic changes in animals has been retracted by the journal Nature Methods. Among those refuting the work were Professor Kent Lloyd, director of the UC Davis Mouse Biology Program, and colleagues from the International Mouse Phenotyping Consortium, whose letter was one of five published by the journal March 30.

CRISPR-Cas9 can be used to introduce very specific edits into DNA. In laboratory mice, the technology could be used to make edits in embryos that are then grown to adult mice. One of the attractions of CRISPR-Cas9 is that it is supposed to make these edits without affecting other genes.

Investigating the Seagrass Microbiome

By Karley Marie Lujan

Seagrass carpets the seafloor creating a unique and vital ecosystem in shallow marine environments. Sea turtles graze on seagrass leaves while smaller organisms seek refuge in the green fields but, on the microscopic level, seagrass is also home to microbial communities. Such microbes compose the seagrass microbiome and potentially play a role in seagrass ecology.

Turtle and seagrass

Sea turtles and other marine animals browse on seagrass meadows. (NOAA photo)

UC Davis graduate student Cassie Ettinger identifies and characterizes seagrass-associated microbial communities. A study published last year in the journal PeerJ suggests how understanding the role of these microbes could reveal new information about seagrass sulfur cycling and establish seagrass as a model organism.

Treating Koalas for Chlamydia Alters Gut Microbes

Koalas are one of Australia’s iconic animals, but they have been hard hit by an epidemic of Chlamydia infections contributing to a steep decline in numbers. Sick koalas brought to wildlife hospitals may be treated with antibiotics to clear up the chlamydia, but the antibiotics themselves can have severe side effects in the animals.


Koalas feed almost exclusively on eucalyptus leaves. They depend on gut bacteria to make the leaves digestible. (Photo via Tourism Australia)

A new study led by Katherine Dahlhausen, a graduate student at the UC Davis Genome Center, published in the journal PeerJ, shows that those antibiotics may be changing the balance of gut microbes thought to allow koalas to digest eucalyptus leaves.