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 us recently to questions about ectodermally-derived structures more generally. In collaboration with Kunxin Luo we are starting a new histological and physiological research project investigating mammary gland ductal branching, especially as it relates to lactation and cancer risk.
We will continue to work on the description of new fossils from Olduvai (Tanzania), the Omo and Middle Awash (Ethiopia), as well as returning to the paleontological survey in Tanzania in 2020. We are always knee-deep in monkey fossils, so our cercopithecoid paleontology will continue for quite a bit longer (follow #TeamMonkey on twitter). And, of course, we have 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).
Large Scale Studies of Skeletal Variation
In a 20-year 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 undertaken 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 article in Evolution (Jan 2013) and others published more recently.
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. The anthropoid primate story was published in the Proceedings of the National Academy of Sciences USA, 2016, 113(33):9262-9267. As for mammals more broadly, check out our latest publication (Ecology & Evolution https://onlinelibrary.wiley.com/doi/full/10.1002/ece3.5309).
Field Paleontology: Olduvai Gorge
Our most recent 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.
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)
