BIOL 3040 Lecture Notes - Great Chain Of Being, Evolutionary Developmental Biology, Ontogeny
Document Summary
13. 1 evo-devo: a brief history: define ontogeny, the development of an individual over its lifetime, compare and contrast the ideas about ontogeny and evolution put forward by the. Greeks, meckel, and von baer: greeks: all life was moving from the simple to the complex (scala naturae). Page 437: acceleration: when a somatic trait is accelerated relative to the appearance of a reproductive trait and the somatic trait appears earlier in development. Axolotls fall under this type of heterochrony: hypermorphosis: when a somatic trait is accelerated relative to the appearance of a reproductive trait and the reproductive trait appears later in development. Formerly seen in adult stage of ancestral species and is now appearing in the juvenile stage of descendant species. 13. 2 regulation, expression, and switches: describe the role of homeotic genes in gene expression and development, homeotic genes are master switch genes that encode proteins that activate or repress gene expression.
