Some of the most famous biologists and their contributions to science are Charles Darwin for the theory of evolution by natural selection, Gregor Mendel for discovering the foundation of modern genetics, and James Watson and Francis Crick for the determining the structure of DNA.
In "On the Origin of Species," Charles Darwin introduced the concept that populations of organisms evolve through the process of natural selection. Darwin posited that nature may select certain traits in the same way that humans breed plants and animals for particular qualities. Over time, populations evolve as nature selects for traits that promote increased survival and reproduction. Today, scientists consider this theory a cornerstone of modern biology.
Gregor Mendel bred pea plants to investigate how parents transmitted traits to offspring. Through these experiments, he formulated the Law of Segregation, which states that dominant and recessive traits are passed on to offspring randomly. Mendel also developed the Law of Independent Assortment, establishing that traits are passed from parent to offspring independently of one another. His findings formed the foundation of the modern understanding of genetics.
James Watson and Francis Crick worked together to determine that DNA has a structure made of a double helix. Many scientists regard this finding one of the most important of the 20th century, as it led to the ability to sequence genes, which is vital to biotechnology and modern medicine.