Explaining Life’s Rapid Evolution on Land

By Becky Oskin

Although life arose in the sea, some of its most astonishing evolutionary leaps happened after organisms conquered land, according to UC Davis paleobiologist Geerat Vermeij. Drawing on his encyclopedic knowledge of evolutionary change in the fossil record,

Living on land brought new challenges and new opportunities for leaps in evolution, argues UC Davis paleobiologist Geerat Vermeij. Photo by Kathy Keatley Garvey.

Vermeij has identified 11 major innovations that appeared first among terrestrial creatures. Vermeij describes the “irreversible shift” in evolutionary dominance from sea to land in a new study published online October 2017 in the journal Current Biology.

How Useful Are Earthquake Early Warning Systems?

Mexico’s earthquake early warning system may have helped save lives in the Sept. 19 earthquake. Sirens in Mexico City sounded seconds before the earthquake struck the city, giving a brief window to shut down vital infrastructure and evacuate buildings. There was more warning, about 90 seconds, before the larger earthquake that occurred off the coast of Mexico Sept. 8.

ShakeAlert is an Earthquake Early Warning system for the US West Coast. It is being developed by the US Geological Survey and a consortium of universities.

A similar system has been tested for the U.S. West Coast including California and is expected to begin limited public operation in 2018.

$1.6M from NSF to Study Water, Land Use in Disadvantaged Communities

By Kat Kerlin

The National Science Foundation has awarded $1.6M to the University of California, Davis to analyze the complex relationships between surface water and groundwater supply, agricultural land use and the economic wellbeing of rural, disadvantaged communities.

The project is led by principal investigator Helen Dahlke, an associate professor in the UC Davis Department of Land, Air and Water Resources. The team will develop models to help guide decision-making regarding water management and land use in the state.

Helen Dahlke in field

Helen Dahlke studies how groundwater is used and replenished in California. (Tiffany Kocis/UC Davis)

Floods, Floodplains and Green Infrastructure in California’s Future

by Peter Moyle, Jeff Opperman, Amber Manfree, Eric Larson, and Joan Florshiem

The flooding in Houston is a reminder of the great damages that floods can cause when the defenses of an urban area are overwhelmed.  It is hard to imagine a flood system that could have effectively contained the historic amount of rain that fell on the region—several feet in just a few days.  However, these floods are a stark reminder of the increasing vulnerability of urban areas across the world and the need for comprehensive strategies to reduce risk.  The evidence is clear that green infrastructure, as defined below, can increase the resiliency of flood management systems and, when managed for multiple services, can reduce flood risk for many people while also promoting a range of other benefits.

Engineer Takes Part in Eclipse Experiment

For most of us Monday’s solar eclipse was a wonderful spectacle, but some scientists were out gathering data, too. Holly Oldroyd, assistant professor in the UC Davis Department of Civil and Environmental Engineering, joined a team led by Chad Higgins at Oregon State University to measure atmospheric fluxes during the eclipse.

As night turns to day and back there are changes in atmospheric temperature and pressure, water vapor and carbon dioxide, and in emissions from soils and plants into the atmosphere. Higgins’ experiment aimed to find out whether the same kinds of changes take place during the very short “night” created by the total solar eclipse. Normally these measurements are taken over time spans of half an hour or so, so the team, which also included researchers at Lawrence Livermore National Laboratory, had to come up with ways to make accurate measurements over a couple of minutes.

Surprise Result: Increasing Dispersal Increases Ecological Diversity

By Kathy Keatley Garvey

A study of microbes that live in the nectar of flowers has turned up an unexpected result that challenges a common assumption in ecology.

It’s been widely assumed that the more easily organisms can disperse between habitats, the more similar the mix of species in those habitats will be.

Sticky Monkeyflower

The flowers of Sticky Monkeyflower contain a mix of microbes that live on nectar. A new study shows how microbial diversity changes between flowers. (Photo by Kathy Keatley Garvey)

Paris Soil Carbon Goals Not Feasible, Because of Nitrogen

By Ann Filmer

Goals for carbon reduction from sequestration in soils set in the 2015 Paris Agreement are not feasible, according to an international team of climate scientists. Regardless of whether the U.S. remains part of the Paris climate accord, scientists at the University of California, Davis, are developing additional agricultural methods to offset increases in atmospheric greenhouse gases, thereby reducing the potential for global warming.

Subsurface drip irrigation

Subsurface drip irrigation in a tomato field at UC Davis. This irrigation method saves water, reduces fertilizer use and reduces emissions of nitrous oxide, a greenhouse gas. Photo by Martin Burger, UC Davis.

Podcast: Synestia, a New Type of Planetary Object

In this month’s Three-Minute Egghead, Sarah Stewart and Simon Lock talk about synestias. A synestia is a new type of planetary object, they proposed, formed when a giant collision between planet-size objects creates a mass of hot, vaporized rock spinning with high angular momentum. Synestias could be an important stage in planet formation, and we might be able to find them in other solar systems.

https://soundcloud.com/user-570302262/three-minute-egghead-synestia-a-new-planetary-object?in=user-570302262/sets/three-minute-egghead-a-podcast

More information

News release: Synestia, A New Type of Planetary Object

New Theory Explains How the Moon Got There

Simon Lock’s Synestia Page

New Technique Provides Earthquake Risk for Major Cities Worldwide

By Larry O’Hanlon

Scientists have developed snapshots of the likelihood of major earthquakes occurring in megacities around the world using a new statistical approach for estimating earthquake risk. The work will be presented today, May 22 at the joint meeting of the Japan Geoscience Union and the American Geophysical Union in Chiba, Japan.

A “nowcast” for Tokyo. The red thermometer at right shows how far along the Tokyo region is in its cycle of smaller quakes between quakes of at least 6.5 magnitude. (John Rundle, UC Davis)

Refining the Ocean’s Thermometer

By Becky Oskin

Chronicling Earth’s past temperature swings is a basic part of understanding climate change. One of the best records of past ocean temperatures can be found in the shells of marine creatures called foraminifera.

The foraminiferan Neogloboquadrina dutertrei forms a record of ocean conditions as it builds its shell. Photo by J. Fehrenbacher

Known as “forams” for short, these single-celled plankton build microscopic calcite shells. When forams die, their shells fall to the ocean floor and accumulate in sediments that provide a record of past climate. The surface-feeding plankton are natural thermometers because the chemical makeup of foram shells is linked to the environmental conditions they grow in. For example, the levels of magnesium in foram shells reflect the seawater temperature in which they lived.