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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 ...
The journals Human Reproduction Update and Molecular Human Reproduction are spin-offs from Human Reproduction that were established in 1995. [2] The main journal concentrates on original research, clinical case studies, as well as opinions and debates on topical issues. [2] Human Reproduction Update is a bimonthly review journal. [4]
1 - morula, 2 - blastula 1 - blastula, 2 - gastrula with blastopore; orange - ectoderm, red - endoderm. Embryology (from Greek ἔμβρυον, embryon, "the unborn, embryo"; and -λογία, -logia) is the branch of animal biology that studies the prenatal development of gametes (sex cells), fertilization, and development of embryos and fetuses.
Originally called Journal of Embryology and Experimental Morphology (ISSN 0022-0752) and established in 1953, the journal provided a periodical that would be primarily devoted to morphogenesis. [4] [5] In 1987, the journal was renamed Development. The journal's full archive from 1953 is available online.
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 ...
Abiogenesis; Aerobiology; Agronomy; Agrostology; Anatomy; Astrobiology; Bacteriology; Biochemistry; Biogeography; Biogeology; Bioinformatics; Biological engineering
Human embryology is the study of this development during the first eight weeks after fertilization. The normal period of gestation (pregnancy) is about nine months or 36 weeks. The germinal stage refers to the time from fertilization through the development of the early embryo until implantation is completed in the uterus .
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.