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. "Heterochrony revisited: The evolution of developmental sequences." Biological Journal of the Linnean Society 73.2 (2001): 169-186. Full Text

Smith, KK. "The evolution of mammalian development." Bulletin of the Museum of Comparative Zoology 156 (2001): 119-135. (Academic Article)

Nishikawa, KC, Kier, WM, and Smith, KK. "Morphology and mechanics of tongue movement in the African pignosed frog Hemisus marmoratum: A muscular hydrostatic model." Journal of Experimental Biology 202.7 (1999): 771-780.

Smith, KK. "Early cranial development in marsupial mammals: The origins of heterochrony." AMERICAN ZOOLOGIST 39.5 (1999): 13A-13A.

Smith, KK, and Schneider, RA. "Have gene knockouts caused evolutionary reversals in the mammalian first arch?." Bioessays 20.3 (March 1998): 245-255. (Review) Full Text

Van Nievelt, AF, and Smith, KK. "Extreme bilateral molar rotation in Monodelphis domestica (Marsupialia: Didelphidae)." Arch Oral Biol 42.8 (August 1997): 587-591. (Review)

Smith, KK, Nievelt, AFHV, and Rowe, T. "Comparative rates of development in Monodelphis and Didelphis." Science 275.5300 (1997): 683-684. Full Text

Sánchez-Villagra, MR, and Smith, KK. "Diversity and evolution of the marsupial mandibular angular process." Journal of Mammalian Evolution 4.2 (1997): 119-144.

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