In the 1962 case Planned Parenthood Committee of Phoenix v. Maricopa County, the Arizona Supreme Court ruled that Arizona Revised Statute 13-213, which banned the public advertising of contraceptive or abortion medication or services, was constitutional. However, the court also ruled that that Arizona Revised Statute 13-213 did not apply to Planned Parenthood's distribution of contraceptive information, allowing Planned Parenthood to continue distributing the information. Following the case, the Arizona law was challenged several times and eventually deemed unconstitutional in the 1973 case State v. New Times INC. The case Planned Parenthood Committee of Phoenix v. Maricopa County established that Planned Parenthood's distribution of medical literature was not advertising as described in the law, and it initiated a decade long discussion about the constitutionality of the laws preventing the distribution of materials related to contraception or abortion.

In Stuart v. Camnitz, the United States Court of Appeals for the Fourth Circuit affirmed the decision of a North Carolina District Court that declared a controversial ultrasound mandate for abortions unconstitutional in 2014. The ultrasound mandate was a part of the Woman’s Right to Know Act introduced in North Carolina in 2011, which placed several restrictions on abortion care providers in the state. If enforced, the ultrasound mandate would have required physicians to perform an ultrasound on every patient before an abortion and simultaneously describe the resulting image of the fetus regardless of whether the woman wanted to hear the description. The District Court ruled the mandate an unconstitutional violation of physicians’ free speech rights. The Fourth Circuit Court’s decision to affirm the District Court’s ruling established that the state could not compel healthcare providers to recite what the court called state ideology to patients against their medical judgment, which broke with precedent set by prior rulings by the Fifth and Eighth Circuit Courts in similar cases.

Mesoderm is one of the three germ layers, groups of cells that interact early during the embryonic life of animals and from which organs and tissues form. As organs form, a process called organogenesis, mesoderm interacts with endoderm and ectoderm to give rise to the digestive tract, the heart and skeletal muscles, red blood cells, and the tubules of the kidneys, as well as a type of connective tissue called mesenchyme. All animals that have only one plane of symmetry through the body, called bilateral symmetry, form three germ layers. Animals that have only two germ layers develop open digestive cavities. In contrast, the evolutionary development of the mesoderm allowed in animals the formation of internal organs such as stomachs and intestines (viscera).

In 1893, Julia Barlow Platt published her research on the origins of cartilage in the developing head of the common mudpuppy (Necturus maculosus) embryo. The mudpuppy is an aquatic salamander commonly used by embryologists because its large embryonic cells and nuclei are easy to see. Platt followed the paths of cells in developing mudpuppy embryos to see how embryonic cells migrated during the formation of the head. With her research, Platt challenged then current theories about germ layers, the types of cells in an early embryo that develop into adult cells. In most organisms' development, three types of germ layers are responsible for the formation of tissues and organs. The outermost layer is called ectoderm, the middle layer mesoderm, and the innermost layer endoderm, although Platt called it entoderm. Platt's research provided a basis for scientists to clarify the destination or function of the germ layers in vertebrates' development.

In the 1973 case State v. New Times, INC, the Arizona Court of Appeals in Phoenix, Arizona, ruled that Arizona Revised Statutes 13-211, 13-212, and 13-213, collectively called the Arizona abortion statutes, were unconstitutional. The statues made it illegal for anyone to receive, provide, or advertise abortion services. The Arizona Court of Appeals reviewed a case in which a city court in Tempe, Arizona, convicted the New Times, a newspaper headquartered in Phoenix, Arizona, of advertising abortion. In hearing the case, the Arizona Court of Appeals deferred to the recently decided US Supreme Court case Roe v. Wade (1973). In Roe v. Wade, the US Supreme Court ruled that women have constitutional rights to abortion services within the first trimester of pregnancy. Accordingly, the Arizona Court of Appeals claimed that all of Arizona's abortion statutes, including the one the New Times was convicted of, prohibited no criminal acts, and set aside New Times's conviction.

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. Gould suggests that, although fewer biologists invoked recapitulation theories in the twentieth century compared to those in the nineteenth and eighteenth centuries, some aspects of the theory of recapitulation remained important for understanding evolution. Gould notes that the concepts of acceleration and retardation during development entail that changes in developmental timing (heterochrony) can result in a trait appearing either earlier or later than normal in developmental processes. Gould argues that these changes in the timing of embryonic development provide the raw materials or novelties upon which natural selection acts.

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
role of development in evolutionary theories. The article suggests
that constraints on how organisms can develop and constraints on how species can evolve from others play a
central role in explaining the how species and traits evolve. The
authors note that organisms from different species develop as
embryos through stages similar across species, genera, and higher
classes. Gould and Lewontin hypothesize that those stages
constrained the possible pathways of evolution and has therefore
guided the history of life. Throughout the paper, the authors rely on analogy of some parts of organisms to architectural structures called spandrels, marked in this image as 'a'."

In humans, sex determination is the process that determines the biological sex of an offspring and, as a result, the sexual characteristics that they will develop. Humans typically develop as either male or female, primarily depending on the combination of sex chromosomes that they inherit from their parents. The human sex chromosomes, called X and Y, are structures in human cells made up of tightly bound deoxyribonucleic acid, or DNA, and proteins. Those are molecules that contain the instructions for the development and functioning of all life forms, including the development of physical traits and body parts that correspond with each biological sex. Humans who inherit two X chromosomes typically develop as females, while humans with one X and one Y chromosome typically develop as males. Sex determination is the beginning of the development of many characteristics that influence how a human looks and functions as well as the societal expectations that other humans have for each other.

The North Carolina state legislature passed The Woman’s Right to Know Act in 2011, which places several restrictions on abortion care in the state. The Woman’s Right to Know Act, or the Act, imposes informed consent requirements that physicians must fulfill before performing an abortion as well as a twenty-four hour waiting period between counseling and the procedure for people seeking abortion, with exceptions for cases of medical emergency. Then-governor of North Carolina Beverly Perdue initially vetoed House Bill 854, which contained the Act, but the state legislature overrode her veto to pass the bill. In response to a lawsuit that the American Civil Liberties Union, or ACLU, and other organizations filed in 2011, a US district court judge blocked the law’s ultrasound mandate from going into effect and a later court case determined that the mandate was illegal. With the passage of the Act in North Carolina, the state passed several abortion regulations and mandated that abortion providers must inform women of specific details about their pregnancy before performing the abortion procedure.

In January 2014, Mary Gatter and colleagues published “Relationship between Ultrasound Viewing and Proceeding to Abortion” in Obstetrics and Gynecology hereafter “Ultrasound Viewing.” As of 2021, ten states require women to undergo an ultrasound before they may consent to having an abortion. Self-described pro-life organizations assert that viewing an image of the fetus will dissuade women from having an abortion. The authors reviewed women’s medical records from over fifteen thousand visits to one abortion provider in 2011.The authors determined viewing an ultrasound image did not change the minds of women who were already highly certain that abortion was the right decision, challenging the idea that mandatory ultrasound viewing has any effect on women’s decision to have an abortion.