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Displaying 76 - 91 of 91 items.

Theodor Heinrich Boveri (1862-1915)

Theodor Boveri investigated the mechanisms of heredity. He developed the chromosomal theory of inheritance and the idea of chromosomal individuality. Boveri sought to provide a comprehensive explanation for the hereditary role and behavior of chromosomes. He hoped that his experiments would also help to distinguish the roles of the nucleus and the cytoplasm in embryogenesis. Boveri was particularly interested in how offspring are shaped by the attributes of their parents.

Format: Articles

Subject: People

Carnegie Institution of Washington Department of Embryology

The Carnegie Institution of Washington's (CIW) Embryology Department was opened in 1914 and remains one of six departments in the CIW. The department quickly became, and remains, world renowned for its many embryonic development discoveries. In 1913 Franklin P. Mall, Professor of Anatomy at Johns Hopkins Medical School, applied for a Carnegie grant to support his research with human embryos. Mall had a collection of over 800 human embryo specimens and was at the point of wanting to do more than just collect.

Format: Articles

Subject: Organizations

Ernest Everett Just (1883-1941)

Ernest Everett Just was an early twentieth century American experimental embryologist involved in research at the Marine Biological Laboratory (MBL) at Woods Hole, Massachusetts, and the Stazione Zoologica in Naples, Italy. Just was known for simple but elegant experiments that supported the "fertilizing" theory of Frank R. Lillie and served as an antagonist to Jacques Loeb's work with artificial parthenogenesis.

Format: Articles

Subject: People

Curt Jacob Stern (1902-1981)

Curt Jacob Stern studied radiation and chromosomes in humans and fruit flies in the United States during the twentieth century. He researched the mechanisms of inheritance and of mitosis, or the process in which the chromosomes in the nucleus of a single cell, called the parent cell, split into identical sets and yield two cells, called daughter cells. Stern worked on the Drosophila melanogaster fruit fly, and he provided early evidence that chromosomes exchange genetic material during cellular reproduction.

Format: Articles

Subject: People

Hermann Joseph Muller (1890-1967)

Hermann Joseph Muller studied the effects of x-ray radiation on genetic material in the US during the twentieth century. At that time, scientists had yet to determine the dangers that x-rays presented. In 1927, Muller demonstrated that x-rays, a form of high-energy radiation, can mutate the structure of genetic material. Muller warned others of the dangers of radiation, advising radiologists to protect themselves and their patients from radiation. He also opposed the indiscriminate use of radiation in medical and industrial fields.

Format: Articles

Subject: People

Matthias Jacob Schleiden (1804–1881)

Matthias Jacob Schleiden helped develop the cell theory in Germany during the nineteenth century. Schleiden studied cells as the common element among all plants and animals. Schleiden contributed to the field of embryology through his introduction of the Zeiss microscope lens and via his work with cells and cell theory as an organizing principle of biology.

Format: Articles

Subject: People

Mammography

Mammography or mastography is an imaging technology used in the twentieth century for the detection of breast cancer and other breast abnormalities. Breast cancer is an abnormal growth in breast tissue that can spread to other parts of the body and cause death. Breast cancer affects about twelve percent of women worldwide. In the twenty-first century, mammography is one of the most accurate tools for screening and diagnosing breast cancer.

Format: Articles

Subject: Technology

A History of Embryology (1959), by Joseph Needham

In 1931 embryologist and historian Joseph Needham published a well-received three-volume treatise titled Chemical Embryology. The first four chapters from this work were delivered as lectures on Speculation, Observation, and Experiment, as Illustrated by the History of Embryology at the University of London. The same lectures were later released as a book published in 1934 titled A History of Embryology.

Format: Articles

Subject: Publications

Barbara McClintock (1902-1992)

Barbara McClintock worked on genetics in corn (maize) plants and spent most of her life conducting research at the Cold Spring Harbor Laboratory in Laurel Hollow, New York. McClintock's research focused on reproduction and mutations in maize, and described the phenomenon of genetic crossover in chromosomes. Through her maize mutation experiments, McClintock observed transposons, or mobile elements of genes within the chromosome, which jump around the genome. McClintock received the Nobel Prize for Physiology or Medicine in 1983 for her research on chromosome transposition.

Format: Articles

Subject: People

Ilya Ilyich Mechnikov (Elie Metchnikoff) (1845-1916)

Ilya Ilyich Mechnikov studied phagocytes, immune function, and starfish embryos in Europe during the late nineteenth and early twentieth centuries. Mechnikov adopted the French form of his name, Élie Metchnikoff, in the last twenty-five years of his life. In 1908, he won the Nobel Prize in Physiology or Medicine with Paul Ehrlich for their contributions to immunology. Mechnikov discovered phagocytes, immune cells that protect organisms by ingesting foreign particles or microorganisms, by conducting experiments on starfish larvae.

Format: Articles

Subject: People

US Regulatory Response to Thalidomide (1950-2000)

Thalidomide, a drug capable of causing fetal abnormalities (teratogen), has caused greater than ten thousand birth defects worldwide since its introduction to the market as a pharmaceutical agent. Prior to discovering thalidomide's teratogenic effects in the early 1960s, the US Food and Drug Administration (FDA) did not place regulations on drug approval or monitoring as it later did. By 1962, approximately 20,000 patients in the US had taken thalidomide as part of an unregulated clinical trial before any actions were taken to stop thalidomide's distribution.

Format: Articles

Subject: Legal, Reproduction

Max Ludwig Henning Delbruck (1906–1981)

Max Ludwig Henning Delbrick applied his knowledge of theoretical physics to biological systems such as bacterial viruses called bacteriophages, or phages, and gene replication during the twentieth century in Germany and the US. Delbrück demonstrated that bacteria undergo random genetic mutations to resist phage infections. Those findings linked bacterial genetics to the genetics of higher organisms. In the mid-twentieth century, Delbrück helped start the Phage Group and Phage Course in the US, which further organized phage research.

Format: Articles

Subject: People

Eugen Steinach (1861–1944)

Eugen Steinach researched sex hormones and their effects on mammals in the late nineteenth and early twentieth centuries in Europe. He experimented on rats by removing their testicles and implanting them elsewhere in their bodies, and he found that the testes interstitial cells produce male sex hormones. He developed the Steinach Rejuvenation Procedure, which he claimed could rejuvenate men by increasing their production of sex hormones. Steinach’s work on female sex hormones and on ovarian extracts led to the development of the first standardized injectable estrogen.

Format: Articles

Subject: People

Essay: Review of Icons of Life: A Cultural History of Human Embryos

To Lynn M. Morgan, the Mary E. Woolley Professor of Anthropology at Mt. Holyoke College, nothing says life more than a dead embryo. In her easily readable book, Icons of Life: A Cultural History of Human Embryos, Morgan brings together cultural phenomena, ethics, and embryology to show that even dead embryos and fetuses have their own stories to tell. As an anthropologist, Morgan is interested in many things, including the science of embryology and its history. But she also wants to know how culture influences our views on embryos and the material practices that accompany their study.

Format: Essays and Theses

Subject: Publications

Stazione Zoologica Anton Dohrn, Naples, Italy

The Stazione Zoologica Anton Dohrn (Anton Dohrn Zoological Station) is a public research institute focusing on biology and biodiversity. Hereafter called the Station, it was founded in Naples, Italy, in 1872 by Anton Dohrn. The type of research conducted at the Station has varied since it was created, though initial research focused on embryology. At the turn of the twentieth century, researchers at the Station established the sea urchin (Echinoidea) as a model organism for embryological research.

Format: Articles

Subject: Organizations, People, Places

The Y-Chromosome in Animals

The Y-chromosome is one of a pair of chromosomes that determine the genetic sex of individuals in mammals, some insects, and some plants. In the nineteenth and twentieth centuries, the development of new microscopic and molecular techniques, including DNA sequencing, enabled scientists to confirm the hypothesis that chromosomes determine the sex of developing organisms. In an adult organism, the genes on the Y-chromosome help produce the male gamete, the sperm cell. Beginning in the 1980s, many studies of human populations used the Y-chromosome gene sequences to trace paternal lineages.

Format: Articles

Subject: Reproduction, Theories