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Displaying 126 - 150 of 261 items.

Ernst Heinrich Philipp August Haeckel (1834-1919)

Ernst Heinrich Philipp August Haeckel was a prominent comparative anatomist and active lecturer in the late nineteenth and early twentieth centuries. He is most well known for his descriptions of phylogenetic trees, studies of radiolarians, and illustrations of vertebrate embryos to support his biogenetic law and Darwin's work with evolution. Haeckel aggressively argued that the development of an embryo repeats or recapitulates the progressive stages of lower life forms and that by studying embryonic development one could thus study the evolutionary history of life on earth.

Format: Articles

Subject: People

John Tyler Bonner (1920- )

The establishment and growth of developmental-evolutionary biology owes a great debt to the work of John Tyler Bonner. Bonner's studies of cellular slime molds have shed light on some of the big questions of biology including the origins of multicellularity and the nature of morphogenesis. The second child of Lilly Marguerite Stehli and Paul Bonner, John Tyler was born 12 May 1920 in New York City and spent his early years in Locust Valley, Long Island (late 1920s), France (1930), and London (1932).

Format: Articles

Subject: People

The Marine Biological Laboratory

The Marine Biological Laboratory (MBL) was founded in 1888 in Woods Hole, Massachusetts. Woods Hole was already the site for the government 's US Fish Commission Laboratory directed by Spencer Fullerton Baird, and it seemed like the obvious place to add an independent research laboratory that would draw individual scientific investigators along with students and instructors for courses.

Format: Articles

Subject: Organizations

Form and Function (1916), by Edward Stuart Russell

In 1916, at the age of twenty-nine, Edward Stuart Russell published his first major work, Form and Function: a Contribution to the History of Animal Morphology. This book has maintained wide readership among scientists and historians since its initial publication, and today is generally recognized as the first modern, sustained study of the history of morphology. In particular, Form and Function incorporates an extensive theoretical analysis of the relationship between embryological studies and comparative morphology in the nineteenth century.

Format: Articles

Subject: Publications

Spermism

Spermism was one of two models of preformationism, a theory of embryo generation prevalent in the late seventeenth through the end of the eighteenth century. Spermist preformationism was the belief that offspring develop from a tiny fully-formed fetus contained within the head of a sperm cell. This model developed slightly later than the opposing ovist model because sperm cells were not seen under the microscope until about 1677.

Format: Articles

Subject: Theories

Leonardo da Vinci's Embryological Annotations

Among his myriad scientific and artistic contributions, Leonardo da Vinci's work in embryology was groundbreaking. He observed and diagramed the previously undemonstrated position of the fetus in the womb with detailed accompanying annotations of his observations. Leonardo was highly paranoid of plagiarism and wrote all of his notes in mirror-like handwriting laden with his own codes, making his writing difficult to discern and delaying its impact.

Format: Articles

Subject: Publications

Artificial Parthenogenesis and Fertilization (1913), by Jacques Loeb

Jacques Loeb is best known for his embryological work investigating parthenogenesis in invertebrates. Artificial Parthenogenesis and Fertilization is a revised and English-translated work from his earlier book, Die chemische Entwicklungserregung des tierischen Eies (1900). Artificial Parthenogenesis describes Loeb's many and varied methodical experiments to initiate egg development without fertilization by sperm. As is true with much of science, some of Loeb's experiments were successful and many were not.

Format: Articles

Subject: Publications

Preformationism in the Enlightenment

Preformationism was a theory of embryological development used in the late seventeenth through the late eighteenth centuries. This theory held that the generation of offspring occurs as a result of an unfolding and growth of preformed parts. There were two competing models of preformationism: the ovism model, in which the location of these preformed parts prior to gestation was the maternal egg, and the spermism model, in which a preformed individual or homunculus was thought to exist in the head of each sperm.

Format: Articles

Subject: Theories

"The Cell-Theory" (1853), by Thomas Henry Huxley

The Cell-Theory was written by Thomas Henry Huxley in Britain and published in 1853 by The British and Foreign Medico-Chirurgical Review. The twenty-two page article reviews twelve works on cell theory, including those in Germany by Caspar Friedrich Wolff in the eighteenth century and by Karl Ernst von Baer in the nineteenth century. Huxley spends much of The Cell-Theory on a cell theory proposed in the late 1830s by Matthias Schleiden and Theodor Schwann in Germany.

Format: Articles

Subject: Publications

Studies in Spermatogenesis (1905), by Nettie Maria Stevens

Studies in Spermatogenesis is a two volume book written by Nettie Maria Stevens, and published by the Carnegie Institution of Washington in 1905 and 1906. In the books Stevens explains the research she conducted on chromosomal sex determination in the sperm and egg cells of insect species while at Bryn Mawr College, near Philadelphia, Pennsylvania. Studies in Spermatogenesis described early examples of chromosomal XY sex-determination.

Format: Articles

Subject: Publications

St. George Jackson Mivart (1827-1900)

St. George Jackson Mivart studied animals and worked in England during the nineteenth century. He also proposed a theory of organismal development that he called individuation, and he critiqued Charles Darwin's argument for evolution by natural selection. His work on prosimians, a group of primates excluding apes and monkeys, helped scientists better investigate the Primate group.

Format: Articles

Subject: People

The Hyde Amendment of 1976

In 1976, the US Congress passed the Hyde Amendment, which banned the use of federal funding to pay for abortions through Medicaid. In 1976, Illinois Congressman Henry J. Hyde proposed the amendment to the Departments of Labor and Health, Education, and Welfare, Appropriation Act of 1977. In 1980, the US Supreme Court in Harris v. McRae (1980) upheld the constitutionality of the Hyde Amendment.

Format: Articles

Subject: Legal

Harris v. McRae (1980)

On 30 June 1980, in a five to four decision, the US Supreme Court ruled in the Case Harris v. McRae that the Hyde Amendment of 1976 did not violate the US Constitution. The Hyde Amendment banned the use of federal funding to pay for any abortion services. The US Supreme Court's decision in Harris v. McRae overturned the decision of McRae v. Califano (1980), in which the US District Court for the Eastern District of New York had ruled that the funding restrictions established by the Hyde Amendment violated the US Constitution. After the US Supreme Court's ruling in Harris v.

Format: Articles

Subject: Legal

Torsten Wiesel (1924– )

Torsten Nils Wiesel studied visual information processing and development in the US during the twentieth century. He performed multiple experiments on cats in which he sewed one of their eyes shut and monitored the response of the cat’s visual system after opening the sutured eye. For his work on visual processing, Wiesel received the Nobel Prize in Physiology or Medicine in 1981 along with David Hubel and Roger Sperry.

Format: Articles

Subject: People

Hodgson v. Minnesota (1990)

In the 1990 case Hodgson v. Minnesota, the US Supreme Court in Washington, D.C., upheld Minnesota statute 144.343, which required physicians to notify both biological parents of minors seeking abortions forty-eight hours prior to each procedure. The US Supreme Court determined that a state could legally require physicians to notify both parents of minors prior to performing abortions as long as they allowed for a judicial bypass procedure, in which courts could grant exceptions. The Supreme Court’s decision in Hodgson v.

Format: Articles

Subject: Legal

Charles Darwin's Theory of Pangenesis

In 1868 in England, Charles Darwin proposed his pangenesis theory to describe the units of inheritance between parents and offspring and the processes by which those units control development in offspring. Darwin coined the concept of gemmules, which he said referred to hypothesized minute particles of inheritance thrown off by all cells of the body. The theory suggested that an organism's environment could modify the gemmules in any parts of the body, and that these modified gemmules would congregate in the reproductive organs of parents to be passed on to their offspring.

Format: Articles

Subject: Theories

Sex in a Cold Climate (1998)

In 1998, Testimony Films released the documentary Sex in a Cold Climate, which reported the true stories of four survivors from the Magdalene asylums in Ireland in the twentieth century. Magdalene asylums, also called Magdalene laundries and homes, were institutions of the Catholic Church that sought to reform women engaged in prostitution and those who birthed children out of wedlock by forcing the women to do hard labor.

Format: Articles

Subject: Outreach, Publications

Minnie Joycelyn Elders (1933–)

Minnie Joycelyn Elders, known as Joycelyn Elders, is a pediatrician and professor at the University of Arkansas for Medical Sciences in Little Rock, Arkansas. In 1953, Elders began to work with the US Army, where she trained as a physical therapist, being the only African American woman in her training class. Elders eventually became a medical doctor in 1956, specializing in pediatric endocrinology. In 1993, then US President Bill Clinton appointed Elders as the Surgeon General for the United States Public Health Service Commissioned Corps, which she served as until 1994.

Format: Articles

Subject: People

Eclipse of Reason (1987)

Eclipse of Reason is a 1987 anti-abortion documentary film directed, filmed, and narrated by Bernard Nathanson, an obstetrician in the US. American Portrait Films released the film in 1987 featuring Nathanson’s commentary and footage of an abortion of a four-month-old fetus. The film also featured the testimony of women who had suffered following similar procedures. In Eclipse of Reason, Nathanson equates the fetus to a person, likening abortion procedures to murder and arguing for the illegalization of abortion.

Format: Articles

Subject: Outreach, Religion

Stem Cells

According to the US National Institutes of Health (NIH), the standard American source on stem cell research, three characteristics of stem cells differentiate them from other cell types: (1) they are unspecialized cells that (2) divide for long periods, renewing themselves and (3) can give rise to specialized cells, such as muscle and skin cells, under particular physiological and experimental conditions. When allowed to grow in particular environments, stem cells divide many times. This ability to proliferate can yield millions of stem cells over several months.

Format: Articles

Subject: Processes

Conrad Hal Waddington (1905-1975)

Conrad Hal Waddington was an embryologist and theoretical biologist. His early experimental work investigated aspects of embryonic induction and the properties of the organizer first identified by Hans Spemann and Hilde Mangold, while his later studies focused on genetic assimilation. Waddington is probably best known for developing the concept of the epigenetic landscape, and he also held significant interest in many different areas ranging from the visual arts and poetry to philosophy.

Format: Articles

Subject: People

Cord Blood Banking

Cord blood banks are institutions designed to store umbilical cord blood (UCB) stem cells. UCB, a source of hematopoietic stem cells (HSCs), has garnered attention from scientific and medical communities since its first successful use in a hematopoietic stem cell transplant (HSCT) in 1988. The umbilical cord is the lifeline by which the growing fetus is nourished by the mother. Once regarded as medical waste, the umbilical cord has become a source of lifesaving treatment.

Format: Articles

Subject: Technologies, Reproduction

Inducing Fertilization and Development in Sand Dollars

Sand dollars are common marine invertebrates in the phylum Echinodermata and share the same class (Echinoidea) as sea urchins. They have served as model laboratory organisms for such embryologists as Frank Rattray Lillie and Ernest Everett Just. Both Lillie and Just used Echinarachnius parma for their studies of egg cell membranes and embryo development at the Marine Biological Laboratory (MBL) at Woods Hole, Massachusetts, in the early 1900s.

Format: Articles

Subject: Processes

Ethics and Induced Pluripotent Stem Cells

The recent development of induced pluripotent stem cells (iPSCs) and related technologies has caught the attention of scientists, activists, politicians, and ethicists alike. IPSCs gained immediate international attention for their apparent similarity to embryonic stem cells after their successful creation in 2006 by Shinya Yamanaka and in 2007 by James Thompson and others.

Format: Articles

Subject: Technologies, Ethics

The Mothers' Clinic

The Mothers' Clinic for Constructive Birth Control was established on 17 March 1921. The first family planning clinic ever established in Great Britain, it was co-founded by Marie Charlotte Carmichael Stopes and her husband Humphrey Verdon Roe at Number 61, Marlborough Road in Holloway, North London. The Mothers' Clinic was one of the highlights of Stopes's extensive career as a proponent of available birth control and women's sexual equality.

Format: Articles

Subject: Organizations, Reproduction