Embryo Project Encyclopedia Articles

In “Testing the Kin Selection Theory: Who Controls the Investments?” Bert Hölldobler and Edward Osborne Wilson discussed the predictive power of kin selection theory, a theory about the evolution of social behaviors. As part of Hölldobler's and Wilson's 1990 book titled The Ants, Hölldobler and Wilson compared predictions about the reproductive practices of ants to data about the reproductive practices of ants. They showed that the data generally supported the expected behaviors proposed by kin selection theory. Later in their careers, both Hölldobler and Wilson argued that kin selection theory provided an insufficient explanation for the evolution of social behavior. Hölldobler and Wilsons' efforts were emblematic of a larger trend among ant researchers and sociobiologists to explain the evolution of social behavior by focusing on the reproductive dynamics of social organisms.

From 1913 to 1916, Calvin Bridges performed experiments that indicated genes are found on chromosomes. His experiments were a part of his doctoral thesis advised by Thomas Hunt Morgan in New York, New York. In his experiments, Bridges studied Drosophila, the common fruit fly, and by doing so showed that a process called nondisjunction caused chromosomes, under some circumstances, to fail to separate when forming sperm and egg cells. Nondisjunction, as described by Bridges, caused sperm or egg cells to contain abnormal amounts of chromosomes. In some cases, that caused the offspring produced by the sperm or eggs to display traits that they would typically not have. His research on nondisjunction provided evidence that chromosomes carry genetic traits, including those that determine the sex of an organism.

Prenatal Care is an educational booklet written by Mary Mills West of the US Children’s Bureau and published by the US Government Printing Office in 1913. The Bureau distributed West’s booklets in response to their field studies on infant mortality, which found that lack of access to accurate health and hygiene information put women and infants at greater than normal risk of death or disease. In Prenatal Care, West offers advice on nutrition, exercise, and personal hygiene during pregnancy and describes the processes of labor and birth. Soon after publication, women all over the US requested copies of Prenatal Care. Millions of copies of Prenatal Care were distributed nationally between 1921 and 1928 as part of educational programs funded by the Sheppard-Towner Act, and the infant mortality rate declined during that period.

Mary-Claire King studied genetics in the US in the twenty-first century. King identified two genes associated with the occurrence of breast cancer, breast cancer 1 (BRCA1) and breast cancer 2 (BRCA2). King showed that mutated BRCA1 and BRCA2 genes cause two types of reproductive cancer, breast and ovarian cancer. Because of King’s discovery, doctors can screen women for the inheritance of mutated BRCA1 and BRCA2 genes to evaluate their risks for breast and ovarian cancer. King also demonstrated the genetic similarities between chimpanzees and humans and helped to identify victims of human rights abuses using genetics. King's identification of the BRCA genes and their relationship to breast and ovarian cancer, both reproductive cancers, has allowed physicians to screen thousands of women for the genes and for those women to choose to undergo preventative cancer treatment to lower their risk of cancer.

In her 2001 paper “Predictors of Postpartum Depression: An Update,” researcher Cheryl Tatano Beck presents the most common risk factors associated with postpartum depression in women. Postpartum depression occurs when women experience symptoms such as tearfulness, extreme mood changes, and loss of appetite for a lengthened period after giving birth. At the University of Connecticut in Storrs, Connecticut, nursing professor Beck updated a previous study of hers by analyzing literature about postpartum depression published in the 1990s. Beck found four predictors of postpartum depression that she had not included in her previous study. “Predictors of Postpartum Depression: An Update” presents risk factors that healthcare professionals can use to predict whether pregnant women are more likely to develop postpartum depression.

In 2000, Catherine Monk, William Fifer, Michael Myers, Richard Sloan, Leslie Trien, and Alicia Hurtado published “Maternal stress responses and anxiety during pregnancy: Effects on fetal heart rate,” in which the authors conducted a study on how pregnant women’s stress and anxiety affects the health of their fetuses. Previous studies had shown that stress and anxiety during pregnancy could cause fetal abnormalities. In their article, Monk and colleagues reported that the fetuses of anxious pregnant women were more likely to have elevated heart rates and increased stress when exposed to stressors than fetuses of non-anxious women. The authors’ findings indicated that fetuses of anxious women display more biological markers of stress than fetuses of non-anxious women.

During the twentieth century, Thomas Raphael Verny studied the way that environment affects a developing fetus’s character and psychological development. Verny studied the concept of memory before birth and covered both the prenatal and perinatal periods, meaning the time the fetus is in the womb and the weeks immediately before or after birth, respectively. During those times, Verny claimed that patterns of maternal attitudes and experiences, such as affection and stress-related emotions, impact the development of the child. Published in 1981, Verny’s book The Secret Life of the Unborn Child presented novel ideas about how pregnant women’s emotional health impacts the psychological, emotional, and physical development of their fetuses, sparking discussion about the importance of maternal emotional health during prenatal development.