Assembly Instructions Included

Charles Darwin was greatly interested in embryological development, but primarily as it showed sequences or stages in form among contemporary species that might reflect their history of shared ancestry, and the inverse problem of using developmental similarity to argue for descent with modification from common ancestry. This chapter refers to biological processes when we use the word "development"- embryology, or the study of growth from conception and how that is guided by genes, homeostasis, or the maintenance of internally stable conditions, and response to environments, how environmental conditions influence gene expression. Evo-devo has perforce generally been centered on practical model systems on which experiments could be done; mice, zebrafish, fruit flies, and the worm C. elegans, among many others. One of the major debates in evolutionary biology has been the degree to which Darwin's ideas of very slow gradualism are accurate, or when and if large changes can occur rapidly.