Kathleen Kovalevski Smith

Professor of Biology

External address: 
130 Science Drive, Room 122 Duke Box 90338, Durham, NC 27708
Internal office address: 
Box 90338, Durham, NC 27708-0338
Phone: 
(919) 684-3402

Overview

My current work is a focus on the relation between evolution and development in the mammalian skull. My model system involves comparisons of development in placental and marsupial mammals. These mammals are characterized by different developmental trajectories, extending back to some of the earliest events of differentiation, largely as a result of their different life history adaptations. My work focuses on a number of different questions. First, what are the differences in the development of the craniofacial region in marsupial and placental mammals? The head is particularly important in the comparison between marupials and placentals, as many cranial systems must be functional at birth in marsupials, despite the fact that morphogenesis has just started. Second, how do the differences in the developmental pattern reflect the necessities of the marsupial reproductive strategy? What is the adaptive significance of the developmental differences and what constraints might be operating? Here I am looking at development not as merely a means to produce an adult, but as a feature that has an evolutionary significance of its own. Third, what can this comparative approach tell us about mammalian head development in general? There are many differences in the way the head develops in marsupials and placentals. It is reasonable to assume that those elements that develop independently (e.g., appear in different temporal or spatial sequences in the two taxa) are elements that are not mechanistically linked or integrated, whereas those that are consistently associated in the two taxa, despite changes in other structures, may be linked by developmental mechanisms. I am using this comparative approach to examine developmental integration and plasticity. Fourth, what are the developmental mechanisms underlying these evolutionary changes? The most significant differences in development in the two taxa reflect differences in the relative timing of the development of the central nervous system and somatic structures. Hypotheses on many levels have been proposed on the possible mechanistic relations between the development of the CNS and the cranial skeleton. To what extent can these hypotheses on mechanistic relation be tested by comparing events in organisms in which the elements are shifted dramatically in time or space? The comparison is, in essence, a natural experiment. Finally, have the specific developmental patterns of marsupial and placental mammals had an impact on the evolutionary diversity and success of these organisms?

My current project focuses on the earliest patterning events. These projects include a study of heterochronies in the earliest morphological and genetic events in the head of marsupial and placental mammals, a study of neural crest in marupial mammals, and a study of patterns of Hox gene expression along the developing body axis, relations between the brain and cranial skeleton.

Degrees & Credentials

  • Ph.D., Harvard University 1980

  • B.A., University of California at Santa Cruz 1973

Smith, KK. "Facial development in marsupials: functional requirements and developmental constraints." AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY (2005): 192-193.

Nievelt, AFHV, and Smith, KK. "Tooth eruption in Monodelphis domestica and its significance for phylogeny and natural history." Journal of Mammalogy 86.2 (2005): 333-341. Full Text

Vaglia, J, and Smith, KK. "Early development of cranial neural crest in the marsupial, Monodelphis domestica." Development and Evolution 5 (March 2003): 121-135. (Academic Article)

Smith, KK. "Time's arrow: heterochrony and the evolution of development." Int J Dev Biol 47.7-8 (2003): 613-621. (Review)

Smith, KK. "Sequence heterochrony and the evolution of development." J Morphol 252.1 (April 2002): 82-97. Full Text

Snchez-Villagra, MR, Gemballa, S, Nummela, S, Smith, KK, and Maier, W. "Ontogenetic and phylogenetic transformations of the ear ossicles in Marsupial mammals." Journal of Morphology 251.3 (2002): 219-238. Full Text

Smith, KK, and Vaglia, J. "Early development of the cranial neural crest, neural tube and paraxial mesoderm in marsupials." AMERICAN ZOOLOGIST 41.6 (December 2001): 1589-1589.

Smith, KK. "Early development of the neural plate, neural crest and facial region of marsupials." J Anat 199.Pt 1-2 (July 2001): 121-131. (Review)

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