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Hemotrophic (blood eating) viviparity means embryos develop in the female's (or male's) oviduct and nutrients are provided directly by the parent, typically via a structure similar to, or analogous to the placenta seen in mammals. [10] Examples of hemotrophic fish include the surfperches, splitfins, lemon shark, seahorses and pipefish.
Their development is stimulated by hormones secreted by the pituitary and adrenal glands, and is induced shortly before the breeding season and discarded after. In some species, at least, there is a correlation between the level of androgens present in the endocrine system and the volume and complexity of tubercle growth. [4] [5]
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 ...
The evolution of fishes took place over a timeline which spans the Cambrian to the Cenozoic, including during that time in particular the Devonian, which has been dubbed the "age of fishes" for the many changes during that period. The Late Devonian extinctions played a crucial role in shaping the evolution of fish, or vertebrates in general. [1]
In fish, waves of calcium released direct the process of cell division by coordinating the mitotic apparatus with the actin cytoskeleton, propagating cell division along the surface, assists in deepening the cleavage furrow, and finally heals the membrane after separation of blastomeres.
Also called functionalism. The Darwinian view that many or most physiological and behavioral traits of organisms are adaptations that have evolved for specific functions or for specific reasons (as opposed to being byproducts of the evolution of other traits, consequences of biological constraints, or the result of random variation). adaptive radiation The simultaneous or near-simultaneous ...
Inversion (evolutionary biology) – Hypothesis in developmental biology; Mosaic evolution – Evolution of characters at various rates both within and between species; Parallel evolution – Similar evolution in distinct species; Quantum evolution – Evolution where transitional forms are particularly unstable and do not last long
As the most celebrated argument in evolutionary biology, (Edwards, 1998, pp. 564–569) Fisher's principle is a staple of popular science books on evolution. For example, see: Gould, Stephen Jay (2002). The Structure of Evolutionary Theory. pp. 648– 649, 678, 692. Dawkins, Richard; Wong, Yan (2004). "The Seal's Tale".