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Karl Ernst von Baer's Laws of Embryology

In 1828, while working at the University of Konigsberg in Konigsberg, Germany Karl Ernst von Baer proposed four laws of animal development, which came to be called von Baer's laws of embryology. With these laws, von Baer described the development (ontogeny) of animal embryos while also critiquing popular theories of animal development at the time.

Format: Articles

Subject: Theories

Karl Ernst von Baer (1792-1876)

Best known for his contributions to the field of embryology, Karl Ernst von Baer also pursued a variety of other areas of study including medicine, botany, zoology, and anthropology. Committing his life to scientific research, von Baer's work led to the advancement of the understanding of mammalian reproduction, development, and organ functioning. His embryological discoveries ultimately led him to a view of development that supported epigenesis and refuted long-held thinking about preformation.

Format: Articles

Subject: People

Ernst Haeckel's Biogenetic Law (1866)

The biogenetic law is a theory of development and evolution proposed by Ernst Haeckel in Germany in the 1860s. It is one of several recapitulation theories, which posit that the stages of development for an animal embryo are the same as other animals' adult stages or forms. Commonly stated as ontogeny recapitulates phylogeny, the biogenetic law theorizes that the stages an animal embryo undergoes during development are a chronological replay of that species' past evolutionary forms.

Format: Articles

Subject: Theories

De ovi mammalium et hominis genesi (1827), by Karl Ernst von Baer

De ovi mammalium et hominis genesi (On the Genesis of the Ovum of Mammals and of Men) is an 1827 pamphlet by Karl Ernst von Baer about the anatomical observation and description of the egg (ovum) of mammals, like dogs and humans. The pamphlet detailed evidence for the existence of the ovum at the beginning of the developmental process in mammals.

Format: Articles

Subject: Publications

Albrecht von Haller (1708-1777)

Victor Albrecht von Haller was an 18th century scientist who did extensive work in the life sciences, including anatomy and physiology, botany, and developmental biology. His embryological work consisted of experiments in understanding the process of generation, and led him to adopt the model of preformationism called ovism (the idea that the new individual exists within the maternal egg prior to conception). Haller was born in Bern, Switzerland, on 16 October, 1708. His mother was Anna Maria Engel, and his father was Niklaus Emanuel Haller.

Format: Articles

Subject: People

Julius von Sachs (1832-1897)

Julius von Sachs helped establish plant physiology through his experiments in latter nineteenth-century Germany. Sachs infused the inchoate discipline of plant physiology with experimental techniques and a mechanistic stance, both of which cemented his place as one of the discipline s founders. Sachs trained a generation of plant physiologists, and his stress on experimentation and mechanism influenced biologists in other disciplines, especially embryologist Jacques Loeb.

Format: Articles

Subject: People

The Origin of Species: "Chapter Thirteen: Mutual Affinities of Organic Beings: Morphology: Embryology: Rudimentary Organs" (1859), by Charles R. Darwin

Mutual Affinities of Organic Beings: Morphology: Embryology: Rudimentary Organs is the thirteenth chapter of Charles Darwin's book The Origin of Species, first published in England in 1859. The book details part of Darwin's argument for the common ancestry of life and natural selection as the cause of speciation. In this chapter, Darwin summarizes the evidence for evolution by connecting observations of development in organisms to the processes of natural selection.

Format: Articles

Subject: Publications

"The Spandrels of San Marco and the Panglossian Paradigm: A Critique of the Adaptationist Programme" (1979), by Stephen J. Gould and Richard C. Lewontin

The Spandrels of San Marco and the Panglossian Paradigm:
A Critique of the Adaptationist Programme, hereafter called
The Spandrels, is an article written by Stephen J. Gould and
Richard C. Lewontin published in the Proceedings of the Royal
Society of London in 1979. The paper emphasizes issues with
what the two authors call adaptationism or the adaptationist
programme as a framework to explain how species and traits evolved. The paper
is one in a series of works in which Gould emphasized the

Format: Articles

Subject: Publications, Theories

1901 Arizona Comstock Law

In 1901, the Arizona Territorial Legislature codified territorial law that illegalized advertising, causing, or performing abortions anywhere in Arizona. The 1901 code, in conjunction with the federal Comstock Act, regulated the advertisement and accessibility of abortion services and contraceptives in Arizona. The Federal Comstock Act of 1873 had illegalized the distribution of material on contraceptives and abortions through the US Postal Services by labeling contraceptive and abortive material as obscene.

Format: Articles

Subject: Legal, RHAZ

The Comstock Law (1873)

The Comstock Law was a controversial law because it limited the reproductive rights of women and violated every person's right to privacy. This federal law was the beginning of a long fight over the reproductive rights of women which is still being waged. Reproductive rights are important to embryology because they lead to the discussions regarding the morality of abortion, contraceptives, and ultimately the moral status of the embryo.

Format: Articles

Subject: Legal, Reproduction

John von Neumann (1903-1957)

John von Neumann was a Hungarian mathematician who made important contributions to mathematics, physics, computer science, and the area of artificial life. He was born in Budapest, Hungary, on 28 December 1903. His mother was Margit von Neumann and his father was Max von Neumann. His work on artificial life focused on the problem of the self-reproduction of machines. Von Neumann initially discussed self-reproducing machines in his Hixon Symposium paper "The General and Logical Theory of Automata" published in 1948.

Format: Articles

Subject: People

Gunther von Hagens (1945- )

Gunther von Hagens invented a plastination technique and created Body Worlds, a traveling exhibit that has made anatomy part of the public domain. Von Hagens invented the plastination technique in 1977 while working at Heidelberg University in Heidelberg, Germany. Von Hagen's plastination technique preserves real bodies and tissues by the removal of the fluid and replacement with resin. Body Worlds features three-dimensional, plastinated human bodies.

Format: Articles

Subject: People, Outreach, Reproduction

The Meckel-Serres Conception of Recapitulation

Johann Friedrich Meckel and Antoine Etienne Reynaud Augustin Serres developed in the early 1800s the basic principles of what later became called the Meckel-Serres Law. Meckel and Serres both argued that fetal deformities result when development prematurely stops, and they argued that these arrests characterized lower life forms, through which higher order organisms progress during normal development. The concept that the embryos of higher order organisms progress through successive stages in which they resemble lower level forms is called recapitulation.

Format: Articles

Subject: Theories

John von Neumann's Cellular Automata

Cellular automata (CA) are mathematical models used to simulate complex systems or processes. In several fields, including biology, physics, and chemistry, CA are employed to analyze phenomena such as the growth of plants, DNA evolution, and embryogenesis. In the 1940s John von Neumann formalized the idea of cellular automata in order to create a theoretical model for a self-reproducing machine. Von Neumann's work was motivated by his attempt to understand biological evolution and self-reproduction.

Format: Articles

Subject: Theories

Gunther von Hagens' Plastination Technique

Plastination is a technique for preserving tissues, organs, and whole bodies for medical purposes and public display. Gunther von Hagens invented a form of the method in 1977 at Heidelberg University in Heidelberg, Germany after observing medical students struggle working with cadavers that quickly decomposed. Von Hagens' body models, referred to as plastinates, have since become widely used educational tools not only for those studying anatomy and medicine, but also for the general public.

Format: Articles

Subject: Technologies

Edward Drinker Cope's Law of Acceleration of Growth

The Law of Acceleration of Growth is a theory proposed by Edward Drinker Cope in the US during the nineteenth century. Cope developed it in an attempt to explain the evolution of genera by appealing to changes in the developmental timelines of organisms. Cope proposed this law as an additional theory to natural selection.

Format: Articles

Subject: Theories

Karl Wilhelm Theodor Richard von Hertwig (1850-1937)

Karl Wilhelm Theodor Richard von Hertwig is an important figure in the history of embryology for his contributions of artificial hybridization of sea urchin eggs and the formulation of his coelom theory. He was born 23 September 1850 in Friedelberg, Germany, to Elise Trapp and Carl Hertwig. Richard and his older brother Oscar began their studies at Jena under the direction of Ernst Haeckel from 1868 to 1871. In 1872 Hertwig became a lecturer in zoology at Jena while Oscar lectured in anatomy and embryology.

Format: Articles

Subject: People

Ontogeny and Phylogeny (1977), by Stephen Jay Gould

Ontogeny and Phylogeny is a book published in 1977, in which the author Stephen J. Gould, who worked in the US, tells a history of the theory of recapitulation. A theory of recapitulation aims to explain the relationship between the embryonic development of an organism (ontogeny) and the evolution of that organism's species (phylogeny). Although there are several variations of recapitulationist theories, most claim that during embryonic development an organism repeats the adult stages of organisms from those species in it's evolutionary history.

Format: Articles

Subject: Publications

“Improving Women’s Health”: Section 3509 of the Affordable Care Act of 2010

In 2010, US Congress enacted section 3509 of the Patient Protection and Affordable Care Act or ACA, to target issues relating to women’s health. The ACA, signed into law by US President Barack Obama, aimed to increase people’s access to high-quality healthcare in the United States.

Format: Articles

Subject: Law

45 CFR 46: Protection of Human Subjects under United States Law (1974)

In the United States, the Code of Federal Regulations Title 45: Public Welfare, part 46 (45 CFR 46) provides protection for human subjects in research carried out or supported by most federal departments and agencies. 45 CFR 46 created a common federal policy for the protection of such human subjects that was accepted by the Office of Science and Technology Policy and issued by each of the departments and agencies listed in the document.

Format: Articles

Subject: Legal

Johann Friedrich Meckel, the Younger (1781-1833)

Johann Friedrich Meckel studied abnormal animal and human anatomy in nineteenth century Germany in an attempt to explain embryological development. During Meckel's lifetime he catalogued embryonic malformations in multiple treatises. Meckel's focus on malformations led him to develop concepts like primary and secondary malformations, atavism, and recapitulation- all of which influenced the fields of medicine and embryology during the nineteenth and twentieth centuries.

Format: Articles

Subject: People

Uniform Anatomical Gift Act (1968)

The Uniform Anatomical Gift Act (UAGA or the Act) was passed in the US in 1968 and has since been revised in 1987 and in 2006. The Act sets a regulatory framework for the donation of organs, tissues, and other human body parts in the US. The UAGA helps regulate body donations to science, medicine, and education. The Act has been consulted in discussions about abortion , fetal tissue transplants , and Body Worlds , an anatomy exhibition.

Format: Articles

Subject: Legal, Outreach, Reproduction

"Experiments in Plant Hybridization" (1866), by Johann Gregor Mendel

During the mid-nineteenth century, Johann Gregor Mendel experimented with pea plants to develop a theory of inheritance. In 1843, while a monk in the Augustian St Thomas's Abbey in Brünn, Austria, now Brno, Czech Repubic, Mendel examined the physical appearance of the abbey's pea plants (Pisum sativum) and noted inconsistencies between what he saw and what the blending theory of inheritance, a primary model of inheritance at the time, predicted.

Format: Articles

Subject: Experiments

Title X Family Planning Program (1970–1977)

The Family Planning Services and Public Research Act of 1970, often called Title X Family Planning Program, is a US federal law that provides federal funding for family planning services to low income or uninsured families. The US federal government passed the law, Public Law 91-572, in 1970 as an amendment to the Public Health Services Act of 1944. The Act created the Office of Population Affairs (OPA) under the Secretary of Health, Education, and Welfare (here called the Secretary).

Format: Articles

Subject: Reproduction, Legal

Christian Heinrich Pander (1794-1865)

Christian Heinrich Pander, often remembered as the father of embryology, also explored the fields of osteology, zoology, geology, and anatomy. He was born in Riga, Latvia, on 24 July 1794. Pander, with an eclectic history of research, is best remembered for his discovery and explanation of the structure of the chick blastoderm, a term he coined. In doing so, Pander was able to achieve the goal set forth by his teacher, Ignaz Döllinger, to reinvigorate the study of the chick embryo as a means of further exploring the science of embryology as a whole.

Format: Articles

Subject: People

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