Seth Finnegan, Professor

Closed (1) The Evolution of Mollusk Shell Ornamentation as a Defense against Predation

Applications for Spring 2018 are now closed for this project.

The Mesozoic era (252 – 66 million years ago) saw the rise of various marine predators such as marine reptiles, shell-breaking crabs, drilling gastropods, and teleost fishes. As a result, predation pressures are suggested to have increased during this ‘Mesozoic marine revolution’, especially towards the end of the Mesozoic in the Cretaceous. The degree to which the behavioral and morphological evolution of prey species was driven by this trend has been hotly debated for decades. If escalation, or predator-driven evolution, is a valid hypothesis, there should be a correlation between the diversity and/or abundance of shell-breaking and drilling predators and the degree of defensive ornamentation and armoring of prey species.

The focus of this exciting research project will be on marine gastropods from the Cretaceous period (145 – 66 million years ago). These invertebrates were abundant during the Cretaceous and were commonly preyed upon by shell-breaking and drilling predators as recorded by attack/repair scars and drill holes. Experimental data show that their shell ornamentation or armor (spines, ribs, etc.) can help to deter predation and lower successful predation rates.

The student will collect data on various types of ornamentation of gastropod mollusks to evaluate whether or not there is a trend towards increased ornamentation throughout the Cretaceous. This research may lead to a presentation of a poster or talk at a conference or symposium, as was done for bivalve mollusks in October 2017.

Day-to-day supervisor for this project: Adiel Klompmaker, Post-Doc

Qualifications: A disciplined and self-directed student with an interest in marine ecology and/or paleontology. Some geological background is a plus, but not required. Familiarity with spreadsheet software such as Excel is a plus.

Weekly Hours: to be negotiated

Related website: http://finneganlab.org

Closed (2) Environmental and Ecological Change in Coastal Marine California from the Pleistocene to today

Applications for Spring 2018 are now closed for this project.

Rapid climate changes during the Pleistocene (2.6 million to 12,000 years ago) caused major biogeographic upheaval among California’s shallow marine communities. However, at present little is known about the precise nature of these climatic changes, thereby hampering our efforts to understand ecological dynamics through this critical interval. This project seeks to understand the magnitude of Pleistocene-modern environmental change through studying isotopic (e.g. δ18O) compositions of Pleistocene and modern mollusk shells.

The URAP student will be supervised by an IB graduate student and will assist in 1) paleontological collecting along the California coast, 2) preparing fossil specimens, and 3) making detailed measurements for isotopic analysis. Through working on this project the URAP student will gain experience in fieldwork, specimen-based lab work, as well as sample preparation and interpretation of stable isotope measurements ran at UCB’s Center for Stable Isotope Biogeochemistry.

Qualifications: Looking for a disciplined and self-directed student with a strong interest in marine ecology and Earth history. Some geological background and familiarity with stable isotope ecology a plus, but not required.

Weekly Hours: to be negotiated

Related website: http://finneganlab.org

Closed (3) Effects of the Uplift of the Isthmus of Panama on the Ecology, Evolution, and Extinction of Caribbean Bivalves

Applications for Spring 2018 are now closed for this project.

The rise of the Isthmus of Panama ~3 million years ago was arguably the most important biotic and oceanographic event of the past 60 million years. By connecting North and South America, the rise of the Isthmus caused the Great American interchange of terrestrial plant and animal species. In the oceans, the rise of the Isthmus had the opposite effect: the Caribbean Sea was cut off from the tropical eastern Pacific Ocean, and formerly continuous marine populations were severed. Prior to the rise of the Isthmus of Panama, the environment of the proto-Caribbean resembled that of the modern-day tropical eastern Pacific, with upwelling of cold, nutrient-rich bottom waters causing strong interannual and seasonal variations in temperature and planktonic productivity. The modern Caribbean does not experience upwelling, and hence temperatures are nearly constant and planktonic productivity very low. Hence, Caribbean species have evolved (or gone extinct) in a radically changed environment for the past 3 million years.

This project will examine how the rise of the Isthmus of Panama affected the evolution and ecology of one major group by looking at the rich fossil record of bivalve mollusks (clams). Bivalves are abundant and very well preserved in marine sedimentary rocks from Central America that span the interval during which uplift of the isthmus occurred. The student will examine fossil collections to characterize the trophic structure, size-frequency distribution, and (in some cases) the age structure of bivalve communities from before, during, and after the uplift of the Isthmus. The student will also examine species stratigraphic ranges (oldest and youngest fossil occurrences) and ecological characteristics to determine how the species that went extinct following uplift of the isthmus differed from those that survived.



Weekly Hours: to be negotiated

Related website: http://finneganlab.org

Closed (4) Which Factors determine Biodiversity and Body Size Patterns in Crustaceans?

Applications for Spring 2018 are now closed for this project.

Increasing temperatures due to climate change facilitate the pole-ward migration of species on land and in the ocean today, which could lead to shifts in patterns of biodiversity and body size. Likewise, climate change throughout the Cenozoic (the last 66 million years) may have resulted in shifts in marine ecosystems. However, habitat type and the evolutionary history of animals may also influence body size and diversity patterns. Using Cenozoic decapod crustaceans, a very diverse and ecologically important group inhabiting all marine habitats, the goal of this project is to test a variety of hypotheses not tested yet previously: (1) diversity increases, while body size decreases towards the tropics; (2) the late Cenozoic cooling led to changes in diversity and body size patterns along the coasts of the Americas; (3) reef environments harbor smaller crustaceans than other habitats; and (4) the body size of crustaceans increased in Cenozoic compared to the much older Mesozoic species.

The student(s) will collect data on the crustacean biodiversity and body size to test one or several of these hypotheses. There may be opportunities to augment the data with data from specimens deposited in the UCMP (University of California Museum of Paleontology).

Day-to-day supervisor for this project: Adiel Klompmaker, Post-Doc

Qualifications: A disciplined and self-directed student with an interest in marine ecology and/or paleontology. Some background in biology or geology is a plus, but not required. Familiarity with spreadsheet software such as Excel is a plus.

Weekly Hours: to be negotiated

Related website: http://finneganlab.org