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Barnosky interviewed about climate change

global changeTony Barnosky, UCMP Curator and Professor of Integrative Biology, discussed a consensus statement to world leaders regarding global change, Maintaining Humanity's Life Support Systems in the 21st Century, this past week in an interview by KQED Science Editor Craig Miller.

Barnosky has been working with the California Office of the Governor to promote science-based solutions to global change problems. With 15 other global change scientists he developed the scientific consensus statement, which has now found its way into a number of state, national, and international discussions about environmental solutions. Since the release of the statement in May, more than 1,000 scientists around the world have endorsed it. Join the scientists and add your name as an endorser of the statement.

Pollen may help solve the mystery of why a pre-Columbian city in Mexico was abandoned

My research focuses on the Holocene geological time period, the last 10,000 years of Earth history. An accurate picture of past climate can help us understand the relationship between past environmental change and ancient societies. In this post, I describe how my summer fieldwork and my broader dissertation project link summer rainfall, microscopic grains of pollen, and an ancient city in Mexico.

The pre-Columbian city of Cantona is an impressive sight, even today. Located near the border of the Mexican states of Puebla and Veracruz, in the Oriental Basin, it covers 12.6 km2 and features a complex network of streets, ball courts, and pyramids. At its peak, between 1,750 and 1,000 calendar years before present, the site was an important Mesoamerican center of trade in obsidian. Archaeological investigations suggest that the city was abandoned abruptly at approximately 1,000 years ago. While the cause is unknown, many have invoked climate change as a possible contributing factor, partially because of the lack of surface water in the region today. This, however, requires an accurate picture of climate change at least 900 years before we had reliable, instrumental measurements of temperature and rainfall.

Cantona ball court

A ball court at the pre-Columbian city of Cantona. Photo by Tripti Bhattacharya.

All is not lost, however. It turns out that past climates leave microscopic traces in lake sediments. A wet climate, for instance, will leave behind different clay minerals than a dry climate. The pollen preserved in lake sediments can also tell us about the regional vegetation at the time the sediments were deposited, which in turn reflects regional climate. Various techniques like radiocarbon dating can be used to establish the age of the sediments. Detailed analysis of pollen composition or sediment geochemistry can therefore provide a long-term perspective on climate change. My research focuses on lake sediments from a volcanic crater lake called Aljojuca that is approximately 30 km south of Cantona. In 2007, a team from the GFZ German Research Centre for Geosciences and Mexico’s Universidad Nacional Autónoma de México took a 12 m sediment core from the lake. Radiocarbon dating suggests that this core contains a continuous, 6,000-year sediment record.

This summer, I collected pollen samples from contemporary vegetation to improve our interpretation of our pollen results from the Aljojuca core. Understanding how vegetation changes along natural gradients of temperature and precipitation (for instance, up the slope of a mountain) can help us interpret the results we see in fossil pollen assemblages. We can even characterize the composition of the pollen created by local vegetation by analyzing the modern pollen preserved in surface soils, small ponds, or even cushions (called polsters) of moss!

Engaging the next generation of geoscientists

Most Earth scientists have vivid memories of their first geological field trip, but how many can say their first experience was as a high school student on a trip led by 15 professors, professional scientists, and college students?

Thirty lucky students from the Bay Area, El Paso, and New Orleans were selected to participate in a ten-day, geology-of-California field trip that started along the San Andreas Fault at Pt. Reyes National Seashore and ended at Yosemite National Park. Led by UCMP Assistant Director Lisa White as part of the METALS (Minority Education Through Traveling and Learning in the Sciences) program, the trip was supported by an NSF collaborative grant between San Francisco State University, University of Texas El Paso, and the University of New Orleans. High school students recruited from each of the participating cities came together on June 10-20, 2013, for a fast-paced field trip led by faculty, graduate students, and educators associated with those universities.

At Pt. Reyes visitor center

Lisa White (second from left) with students at the Pt. Reyes National Seashore visitor center.

At Tomales Bay

Students on their way to see exposures of invertebrate fossils along Tomales Bay, east of Inverness ridge.

Lisa said, "Having directed the program for four years, my expectations for the student participants grow higher each year, and I am never disappointed. We create opportunities for the students to not only learn in a field setting but also to compete for awards by demonstrating an understanding of key concepts, making rock and fossil identifications, and producing outstanding field interpretations. The students, many of whom have spent little time outdoors or at the coast or in the mountains, have fun testing their endurance and enjoying learning in a natural setting."

The overriding goal of the METALS program is to raise awareness about the geosciences and to increase the numbers and diversity of students choosing academic paths in geoscience and related careers. What better way to showcase Earth science than through fun and exciting field work?

Snow at Lassen

The students enjoyed the snow they found at Mt. Lassen.

Group photo

The trip participants posed for this group photo at Mt. Lassen. All the photos in this post are courtesy of Lisa White.

Fossil bridging with the Girl Scouts

What Bay Area event brings together 5,000 eager girls, 50 exhibitors and a walk across the Golden Gate Bridge? Girl Scout Bridging! On Saturday, May 11, Lisa White, UCMP Director of Education and Public Programs, and Erica Clites, Museum Scientist, attended the annual Girl Scout event at Crissy Field in the Presidio of San Francisco. The Bridging is a symbolic event recognizing the transition from the Junior level of Girl Scouting to Cadette, and the girls — representing troops throughout the western states — still had plenty of energy to learn about the history of life and engage with fossils following their bridge walk!

At the UCMP table

Lisa White and Erica Clites are ready for those Girl Scouts. Note the Golden Gate Bridge in the background, partially concealed by fog.

Erica and Girl Scouts

Erica shows interested Girl Scouts a mammoth tusk and other fossils found in the Bay Area. Both photos courtesy of Lisa White.

Marshall shows terrestrial mammal extinction due to Red Queen with new work published in Science

By studying 19 groups of Cenozoic mammals Charles Marshall and Tiago Quental tested and confirmed the Red Queen hypothesis. Red Queen is the hypothesis that states that groups must continue to adapt and evolve in response to their environments in order to survive. It's not just extinction events that threaten groups--it's also low rates of origination of new species. The new research (published in Science) shows that these mammal groups have experienced diversity declines in part due to their failure to keep pace with their deteriorating environments.

Read the UC Berkeley News Center story about this work.

Read the Science paper.

Warmer climates can lead to big lizards

A mounted modern lizard alongside the fossil jaw bones.

Pat Holroyd and co-authors describe a new species of giant lizard in the latest issue of Proceedings of the Royal Society B. The fossil jaw bones of this lizard have been in the UCMP collection since the 1970s, but it took a while for them to be recognized as something special. The specimens are from an herbivorous lizard that lived in the warm climate of Asia 40 million years ago. Dubbed Barbaturex morrisoni, this lizard was much bigger than the largest herbivorous lizards alive today. The unique traits of this lizard indicate that a warmer climate may have enabled gigantism via increased floral productivity and metabolic rates.

 

Read the press release at the UC Berkeley Newscenter.

 

Read the full paper at Proceedings of the Royal Society B.

Reports from Regatta: T.W. Stanton, prominent contributor to the USGS Invertebrate Collection

In the orphaned U.S. Geological Survey’s (USGS) Menlo Park Invertebrate Collection, now housed in the UC Museum of Paleontology’s off-campus collections space in the Regatta Building, the work of prominent USGS collectors stands out. One of these dedicated and proficient invertebrate paleontologists was Timothy William Stanton, who amassed collections from over 100 localities, authored monographic research papers, and wrote more than 600 technical reports evaluating the age of collected specimens.

Stanton was born on September 21, 1860, in Monroe Country, Illinois. Early in his life, Stanton moved to Boulder, Colorado, where he received his Bachelor of Science and Master of Science from the University of Colorado. Stanton continued his graduate education in biology and geology at John Hopkins University and received a doctoral degree in those disciplines in 1897 from George Washington University.

Stanton’s name is encountered most often in association with Cretaceous invertebrates. His affinity for Cretaceous invertebrates developed when he lived in Boulder, surrounded by fossil-rich sediments of Cretaceous age. Stanton incorporated his research interests into his professional life when he was hired at the USGS and worked as an apprentice to Charles Abiathar White in the Cretaceous invertebrate collection. Starting in 1889, Stanton slowly made his way up the USGS ladder; he succeeded White as the head of the Cretaceous invertebrate collection, became the geologist in charge of the Paleontology and Stratigraphy branch, and in 1932, he became chief geologist of the USGS. Additionally, Stanton served as the president of the Geological Society of America and president of The Paleontological Society.

Bivalves

Bivalve specimens collected by Stanton in the Santa Susana Mountain Range, just north of Los Angeles. These specimens were collected during October of 1900, and constitute a small sample of Stanton’s fieldwork along the Pacific Coast. USGS Locality Number 2251.
 

During his time at the Survey — that spanned over 46 years — Stanton maintained field research in Texas, Colorado, the Gulf Coastal Plain, and the Pacific Coast. While working in Colorado, Stanton produced a comprehensive description of Cretaceous fauna in a monograph entitled The Colorado Formation and Its Invertebrate Fauna. The work is still valued as a remarkable text.

Stanton retired from the Survey in 1935, however, he continued to act as the Custodian of Mesozoic Invertebrates at the US National Museum (now the National Museum of Natural History) until his death in 1953. Throughout his career, Stanton managed a balancing act between acquiring remarkable collections from his fieldwork efforts and the responsibilities of the multiple positions he held at the USGS. Stanton’s success is both reflected in the history of the USGS and his contributions to the Menlo Park Collection. UCMP is honored to permanently house this collection and to manage its care and access for current and future scientists. The collection is a remarkable paleontological record that is being updated and cared for by UCMP students and scientists in the 21st Century.

Invertebrate specimens

Various Cretaceous invertebrate specimens collected by Stanton during September of 1900 in Colusa County, CA. USGS Locality Number 2290. Photos by Michelle Sparnicht.

Small discoveries from the Caldecott Tunnel Project

Observing the tooth

 

Some of the most interesting fossils a paleontologist can find in the field are not necessarily the biggest. During construction of the fourth bore of the Caldecott Tunnel, scientists working with the California Department of Transportation (CalTrans) collected micro-vertebrate fossils, including teeth, jaws and even toes of small animals such as rodents and amphibians. Sediment thought to contain potential fossils was washed through mesh screens, and the remaining material was carefully examined under a microscope to identify and collect any fossil remains too small to be noticed otherwise.

Every tiny bit helps. These miniscule finds represent the first rodents to be recovered from the 12-million-year-old layer of rock known as the Orinda Formation. Studying the large animals living at this time, exotic creatures such as camels and rhinos once common in North America, can only provide a partial window into the past. Smaller animals often lived more specialized lifestyles, a frog who must live close to water or a gopher who burrows and collects seeds. Knowing these animals were present allows us to infer more about the local environment than the presence of more cosmopolitan animals such as horses, who could roam in much wider areas.

Rodent tooth

Above is the lower jaw of an extinct rodent known as Copemys. Its modern cousins include voles, lemmings and hamsters. Even though the jaw is only 1 centimeter across, it holds the potential to tell us much about life in the Bay Area ~11 million years ago.

Hypolagus tooth

This tiny tooth, just 1 millimeter wide, is from an extinct rabbit called Hypolagus. The peg-like cusps are a feature characteristic of rabbits. All photos by Jason Carr.
 

Paleontologists are interested in not only studying the evolution of organisms, but also of communities and ecosystems. In order to deduce how organisms in an environment interacted the more you know the better, and every little bit helps.

Werning blogs at PLOS about the fossils of the Sierra Nevada

In her latest post over at the Public Library of Science blog The Integrative Paleontologists Sarah Werning writes about about what the fossil history of California can teach us about climate change. UCMP is teaming up with other Berkeley natural history museums on the Berkeley Initiative in Global Change Biology to strive for a comprehensive picture of the effects of climate change on past, present, and future life.

Read Sarah's post here.

UCMP students honored with 2013 Paleontological Society Student Grants Awards

Dori Contreras (Looy Lab), Renske Kirchholtes (Looy Lab), and Allison Stegner (Barnosky Lab) will each receive awards from The Paleontological Society to support their research. Each year the Society grants Mid-America Paleontology Society (MAPS) Outstanding Research Awards to the top three student proposals received and honors a student with the G. Arthur Cooper Award for student research.

Dori, Renske, and Allison

Dori Contreras (left), Renske Kirchholtes (center), and Allison Stegner (right) busy at UCMP's Cal Day open house.
 

Dori Contreras will receive a MAPS Outstanding Student Research Award to support her research titled: Investigating the evolution of tropical rainforests: A functional analysis of the late Cretaceous Jose Creek Member, McRae Fm.

Renske Kirchholtes will receive a MAPS Outstanding Student Research Award to support of her research titled: Phytoliths: a novel application to answering ancient questions.

Allison Stegner will receive the G. Arthur Cooper Award to support her research titled: Assessing small mammal response to Quaternary climate and land use change on the Colorado Plateau.