Russian biologist Aleksandr Kovalevskii (Kowalevsky) is notable for his foundational contributions to modern comparative embryology. Raised in a secular society with his brother Vladimir, Kovalevskii received his master’s degree from St. Petersburg University for his studies of Amphioxus lanceolatus. The results from his research gained him admittance into the Russian Academy of Sciences, the Paris Academy of Sciences, and the Royal Society of London. Although Kovalevskii had won acclaim and prestige for his research, civil and academic political restraints prevented him from teaching at the leading academic centers of St. Petersburg and Moscow. Resigned to less-equipped provincial universities, he spent the rest of his academic career in Kazan, Kiev, and Odessa. In honor of Kovalevskii’s achievements, the St. Petersburg Society of Naturalists created an international award, The Kovalevskii Medal, for advancing accomplishments in comparative embryology and zoology within an evolutionary framework. Applied to the study of phylogenetic relationships, Kovalevskii’s contributions are foundational to Russian Darwinism.
Contributions and Perspectives
Influenced by Charles Darwin’s theory of organic evolution, Kovalevskii’s research into evolutionary embryology yielded insights into the relationships among species within a taxonomical framework. In his inquiry into the vertebrate Amphioxus lanceolatus, Kovalevskii suggested that this species could represent a transitional phase between vertebrates and invertebrates. Upon his initial research, he found that the embryonic development depicted two distinct developmental phases; the first phase resembles invertebrates, and the second phase resembles vertebrates. During this process, appearance of both egg and blastula is later followed by an embryo with both internal and external germ layer found in vertebrates. It was shown that within embryonic development, both vertebrates and invertebrates are similar; consequently, this discovery resulted in the reclassification of the lancet from vertebrate to invertebrate. Furthermore, Kovalevskii’s inquiry into ascidians provided evidence that the developmental growth of these sea organisms closely parallels vertebrate development. Inquiry into embryonic development of other invertebrates exhibits similar development. Similar to Darwin’s experiences that led to his discovery of organic evolution, Kovalevskii’s study of marine life led to the finding of related species among the waters of both the Red and Mediterranean Seas. His findings provided further support for Darwin’s scientific determination and opinion regarding embryonic development as possible terms in taxonomical evaluations.
Although Darwin’s theory of organic evolution was not without its critics in Russia, most notably Karl von Baer (1792-1876), the mainstream of anti-Darwinian thought consisted of objections to transitional forms of species. Insufficient comprehension of heredity (genes and mutations) and the nature of adaptation allowed for the resurging fundamental principles of Aristotle (348-322 BCE) and Carol Linnaeus (1707-1778). Steeped in teleology and a designed ontology, the ensuing political climate (academic and social) differed slightly from today. In spite of this climate, Kovalevskii contributed evidence to the validity of Darwin’s theory of evolution with the mechanism of natural selection within the biological sphere of marine life. Kovalevskii corresponded with Darwin, informing Darwin as to advancements in his own research and assisting with the translation of Darwin’s publications that influenced embryology in both Russia and Western Europe.
References:
- Gould, S. J. (2002). The structures of evolutionary theory. Cambridge, MA: Harvard University Press.
- Vucinich, A. (1988). Darwin in Russian thought. Los Angles: University of California Press.
