Developmental biology is the study of how multicellular organisms grow, develop, and change over their lives. It incorporates elements of such disciplines as cell biology, embryology, evolution, and genetics. Historically, developmental biologists studied the cellular processes and the changes in function that take place as an animal grows from fertilized egg to an adult. The field has expanded to include the study of plant development, of natural changes that accompany aging and death, and of the genes that regulate developmental processes. A related branch of study is called evolutionary developmental biology, often abbreviated evo-devo. It is concerned with how changes in developmental processes have led to the wide variety of species that exist today.
In species that reproduce sexually, a new individual begins with the fusion of two gametes (reproductive cells), such as sperm and egg. The resulting cell, called a zygote, divides to form a multicellular embryo. As the embryo grows and develops, different groups of cells become specific tissues and organs. This process is regulated by specific genes. The genes work in a precise sequence to produce a particular arrangement of tissues, organs, and limbs. Developmental biologists study all aspects of this process.
Developmental biology helps scientists understand how an organism’s development is affected by chemical, genetic, and environmental mechanisms. It provides insights into normal life processes, such as aging, and how changes in such processes may cause birth defects, disease, or other disorders.
See also Evolutionary developmental biology ; Homeobox genes .
