Research

An Integrative Approach

For well over a decade, we’ve explored how genes influence skeletal variation and how this has evolved through time. Lab members have used quantitative genetic approaches, studied gene expression in early development, and assessed in utero effects on bone development. All the while, we conducted paleontological field research in Tanzania, Kenya, and Ethiopia to collect evidence of how skeletal morphology has evolved over geological time.

All of the work we’ve done on the genetics of teeth drew me very recently to questions about ectodermally-derived structures more generally. We will be moving into new lab space within the next 6 months (but it is UC Berkeley, so this means any time between now and 2020). With that move will come opportunities for new histological and physiological research along those lines.

We will continue to work on the description of new fossils from Olduvai (Tanzania), Omo and the Middle Awash (Ethiopia), as well as returning to the paleontological survey in Tanzania hopefully in 2018 or 2019. We are always knee-deep in monkey fossils, so our cercopithecoid paleontology will continue for quite bit longer. And, of course, we have a lot of continuing projects that explore large phenotypic datasets to discern the underlying genetic architecture, ranging from a new NSF-funded collaboration of dental & skeletal variation in macaque hybrids (project directed by Tim Weaver at the University of California Davis) to extensions of our MMC and PMM phenotypes (2016_PNAS).

Field Paleontology: Olduvai Gorge

Our primary field project is the the Olduvai Vertebrate Paleontology Project, and its complement the Comprehensive Olduvai Database Initiative. Please visit the project website at www.olduvai-paleo.org for information on these National Science Foundation supported endeavors.

Photo credit: Whitney Reiner, 2008
Photo credit: Whitney Reiner, 2008

Field Paleontology: The Tanzania Survey Project

The Olduvai project started as an off-shoot of the Tanzanian International Paleoanthropological Research Project. TIPRP is co-directed by Drs. Hlusko and Jackson Njau from Indiana University. Tanzania remains relatively unexplored in terms of human evolutionary research. All of the known sites that have yielded remains of our ancestors are located in the north, such as Olduvai Gorge and Laetoli. We studied recently released NASA satellite imagery (thank you Google Earth for help with a lot of this work) and geological maps, and from these found potentially fossiliferous sediments in areas that have not yet been explored for their paleoanthropological potential. Our goal is to inventory and document previously unknown localities. Results from our first few years of fieldwork have been published in the Journal of Human Evolution (2010, vol 59:680-684) and Geochimica et Cosmochimica Acta (2012, vol 93:129-142)

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TIPRP field crew, 2008. Photo credit: L. Hlusko

Large Scale Studies of Skeletal Variation

In collaboration with Dr. Michael Mahaney at the University of Texas Rio Grande Valley School of Medicine and other scientists at the Southwest National Primate Research Center, Dr. Hlusko has been undertaking a quantitative genetic analysis of dental variation in baboons. This work, published primarily between 2001 and 2011, provided the foundation for our research exploring the genetic architecture across primates, for example, see our cover article in Evolution (Jan 2013) and others published more recently.

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The baboon quantitative genetics research spun off into a quantitative genetic analysis of dental variation in wild type mice, finding a conserved pattern of genetic modularity (Molecular and Developmental Evolution, 2011, vol 316B:21-49). We hypothesize that this genetic modularity underlies mammalian dental variation more broadly. We are currently working on a project quantifying dental variation across numerous mammalian groups to test this. The anthropoid primate story was published in the Proceedings of the National Academy of Sciences USA, 2016, 113(33):9262-9267. The hominid-specific and mammals-more-broadly manuscripts are just about ready to be submitted.