Kathleen K Smith, Professor
PhD, Harvard University, 1980
BA, University California, Santa Cruz, 1973
Organismal Biology and Behavior
Research Categories: Functional morphology and evolution of vertebrates; craniofacial development, evolutionary morphology
Research Description: I am interested in the functional and evolutionary morphology of vertebrates. My research has included the functional and phylogenetic significance of variations in form of craniofacial structures in squamate reptiles and mammals, the biomechanics of a class of structures called musculohydrostats, and the roles of adaptive evolution and constraint in morphological diversification. My current focus is on the relation between evolutionary and developmental processes, with particular focus on the evolutionary, functional and developmental consequences of heterochronies in the morphogenesis of cranial nerves, muscles, bones and sensory structures in eutherian and metatherian mammals.
I have shown that one of the most fundamental differences between the two taxa is a delay in marsupials of the development of the central nervous system (CNS) and cranial sense organs and an advancement of certain cranial skeletal-muscular tissues. Specifically, in marsupials the central nervous system and particularly the forebrain is delayed relative to the development of the bones around the oral apparatus, the chondrocranium and the differentiation of cranial muscles. Currently my work is focused on the timing and pattern of early neural crest migration in marsupials. In recent years I have demonstrated that neural crest differentiates and migrates earlier in marsupials, relative to neural tube or somite differentiation, than in another other vertebrate thus far reported. I am now focusing on the patterns of expression of major genes thought to impose regional identity on the neural crest and neural tube.
In addition I am looking at the phylogenetic context of these heterochronies, with a comparative study of early development in therian mammals, monotremes, and non-mammalian amniotes in order to identify the primitive developmental condition for mammals.
- K.K. Smith, THE PLACENTA IN THERIAN MAMMALS: NEW VIEWS ON THE MARSUPIAL PLACENTAL DICHOTOMY, in Great Transformations in Vertebrate Evolution., edited by Dial, Ken, Shubin, Neil, Brainerd, Elizabeth (2014), University of California Press (this was an invited chapter and was peer reviewed..) .
- Keyte, A; Smith K. K., Heterochrony in somitogenesis rate in a model marsupial, Monodelphis domestica, Evolution and Development, vol. 14 (2012), pp. 93-103 [doi] .
- Price S.A., Hopkins S.B, Smith K.K., Roth V.L., Tempo of trophic evolution and its impact on mammalian diversification, PNAS, vol. 109 (2012), pp. 7008-7012 .
- J.K. Moustakas, K.K. Smith, L.J Hlusko, Evolution and development of the mammalian dentition: Insights from the marsupial Monodelphis domestica, Developmental Dynamics, vol. 240 (2011), pp. 232-239 (Online version published in advance of print. Online publication date 24 November, 2010.) [abstract], [doi] .
- A. L. Keyte, K.K. Smith, Developmental origins of precocial forelimbs in marsupial neonates, Development, vol. 137 (2010), pp. 4283-4294 [full], [doi] .