Here, we give an overview of the history of developmental biology, from its beginnings in ancient civilizations to modern synthetic biology that allows systems to manipulate and design biological systems with sophisticated genetic tools.
What is Developmental Biology?
Developmental biology is an important field of science that allows us to understand how organisms, including humans, grow and develop from a molecular or genetic perspective.
Developmental biology encompasses a range of scientific disciplines, including molecular biology, genetics, embryology, the biology of regeneration, and metamorphosis. The progress that has been made by developmental biology has played a vital role in understanding human and animal life, genetics, evolution, and human health.
Early Developmental Biology
The earliest recorded observations that relate to the field of developmental biology date back to the time of the ancient Greeks and the ancient Romans. Aristotle, the famous Greek philosopher who lived between 384 and 322 BC, made important contributions to the beginnings of developmental biology with his observations of chick embryo development. For his work in this field, he is considered the first embryologist in history.
The Advancement of the Microscope
The invention of the microscope propelled developmental biology forward. Before the microscope, the smallest things humans could see were about the width of a human hair. With the microscope, the inner workings of the cell began to be unveiled. Although the microscope was invented in 1590, it was not until later on, following the development of the equipment, that microscopic studies began to advance the field of developmental biology. Notably, during the 17th and 18th centuries, pioneering researchers Marcello Malpighi, an Italian biologist, and Antonie van Leeuwenhoek, a Dutch microbiologist, made important contributions by observing the embryos of various organisms with the use of the microscope.
Preformation Versus Epigenesis
During this period, the debate of preformation versus epigenesis dominated the field of developmental biology. Some scientists believed miniature versions of full-sized organisms existed within the egg or sperm. On the other hand, other scientists believed that organisms developed thanks to the process of gradual differentiation and growth from simple to complex cellular structures. The process of epigenesis highlighted the role of environmental factors in development. As studies became more sophisticated, they were able to begin to validate the core principles of epigenesis.
19th-Century Cell Theory
Later, in the 19th century, pioneering scientists Matthias Schleiden and Theodor Schwann developed their cell theory - work that paved the way to understanding the development of organisms at a cellular level. During this time, German scientists Karl Ernst von Baer, known as the father of embryology, discovered the mammalian ovum and the notochord.
In the same year that von Baer discovered the ovum, he published his seminal book entitled “Mammalian Ovum and the Origin of Man”. Through his extensive research, von Baer was able to establish his laws of embryology, which led to advancing our understanding of mammalian reproduction and development.
The 19th century was also the time during which one of the world’s most influential scientists was doing his work. Charles Darwin established a new branch of science through his theory of biological evolution by natural selection, known as evolutionary biology.
Darwin’s scientific accomplishments were diverse and plentiful; not only did he form a new branch of science, but he changed the way we viewed human history - his theory challenged Christian teachings and allowed us to understand what it is to be human in a new light. At this time, embryology became intertwined with Darwin’s theory of evolution as scientists recognized its relevance to developmental processes.
Perhaps the most important discovery of the 20th century was that of the structure of DNA. In 1953 American biologist James Watson and English physicist Francis Crick (aided by Rosalind Franklin’s X-ray diffraction work) discovered DNA’s double helix structure. This work revolutionized developmental biology. Following this, key developmental genes were identified and the genetic principles that govern living organisms began to unravel. Throughout the 20th century, scientists gained deeper insights into the role of genes in cell signaling, cell fate determination, and pattern formation, amongst other functions, which provided important insights into developmental mechanisms.
21st-Century Stem Cell Research
At the tail-end of the 20th century and into the 21st century, scientists have studied stem cells and their potential applications in tissue regeneration. During the 1990s, stem cell research was a hot topic that often divided experts and the public. The stem cell research debate is a modern example of why ethics must be carefully considered in science, particularly biological science. In 1996 the Dolly the sheep became the world’s first successfully cloned mammal. Cloning has important implications for developmental biology; it opened up the avenue for scientists to explore the role of genetics and to imagine the possible applications of cloning for therapeutic endeavors.
Modern-day Synthetic Biology
The most recent developments in the field of developmental biology have involved the emergence of synthetic biology - an interdisciplinary field that aims to create biological functions or organisms with features that do not occur naturally. The goal of this field of science is to engineer biological systems that have specific capabilities. In the future, this could lead to improvements in a number of sectors, including healthcare and pharmaceuticals, agriculture and food production, environmental sustainability, energy production, materials science, education and research, artificial intelligence, bioinformatics, and more.
Developmental biology is still a rapidly developing field of science; we can expect many future developments and breakthroughs. Advances in related fields of science, including bioinformatics, imaging, and genetics, will help to facilitate further breakthroughs in developmental biology. In the future, we can expect to discover more about the workings of humans and animals and learn how to modify this - most likely in the context of providing better healthcare. However, as our technology becomes more sophisticated and we gain deeper and deeper insights into cellular processes, it is important that the ethics of altering natural processes are considered so that knowledge gained by developmental biology is always used safely and appropriately.
Dolly the sheep becomes first successfully cloned mammal [online]. History. Available at: www.history.com/.../first-successful-cloning-of-a-mammal
Ernst Mayr. (2009). Darwin's Influence on Modern Thought [online]. Scientific American. Available at: www.scientificamerican.com/.../
Zagris, N. (2022) ‘Aristotle (384-322 BC): The Beginnings of Embryology’, The International Journal of Developmental Biology, 66(1-2–3). pp. 5–8. doi.org/10.1387/ijdb.220040nz.