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The theory of recapitulation, also called the biogenetic law or embryological parallelism—often expressed using Ernst Haeckel's phrase "ontogeny recapitulates phylogeny"—is a historical hypothesis that the development of the embryo of an animal, from fertilization to gestation or hatching (), goes through stages resembling or representing successive adult stages in the evolution of the ...
Gould laid to rest Haeckel's interpretation of evolutionary embryology, while Jacob set out an alternative theory. [10] This led to a second synthesis, [29] [30] at last including embryology as well as molecular genetics, phylogeny, and evolutionary biology to form evo-devo.
For example, numerous invertebrate species release a larva before development is complete; at the end of the larval period, an animal for the first time comes to resemble an adult similar to its parent or parents. Although invertebrate embryology is similar in some ways for different invertebrate animals, there are also countless variations.
For example, German biologist and philosopher Ernst Haeckel proposed that all organisms went through a "re-run" of evolution he said that 'ontogeny repeats phylogeny' while in development. Haeckel believed that to become a mammal , an embryo had to begin as a single-celled organism, then evolve into a fish, then an amphibian, a reptile, and ...
Some examples of evolution in species over many generations are the peppered moth and flightless birds. In the 1930s, the discipline of evolutionary biology emerged through what Julian Huxley called the modern synthesis of understanding, from previously unrelated fields of biological research, such as genetics and ecology, systematics , and ...
Experimental evolution uses controlled experiments to test hypotheses and theories of evolution. In one early example, William Dallinger set up an experiment shortly before 1880, subjecting microbes to heat with the aim of forcing adaptive changes. His experiment ran for around seven years, and his published results were acclaimed, but he did ...
Most land plants share a common ancestor, multicellular algae. An example of the evolution of plant morphology is seen in charophytes. Studies have shown that charophytes have traits that are homologous to land plants. There are two main theories of the evolution of plant morphology, these theories are the homologous theory and the antithetic ...
In developmental biology, von Baer's laws of embryology (or laws of development) are four rules proposed by Karl Ernst von Baer to explain the observed pattern of embryonic development in different species.