Famous 19th Century Biologists

Widely regarded as one of the most influential personalities in the history of mankind, Charles Darwin was an English biologist, naturalist, and geologist. He is credited with publishing the Theory of Evolution, which explains the evolution of life from a unicellular organism to human beings. A prolific writer, Charles Darwin also wrote important books on plants and barnacles.

Alexander Fleming was a Scottish microbiologist and physician. He is credited with discovering penicillin, the world's first effective antibiotic substance; a discovery that changed the course of history. He also discovered lysozyme, an antimicrobial enzyme which forms part of the innate immune system. In 1999, Fleming was named in Time magazine's 100 Most Important People of the 20th century list.

British naturalist Alfred Russel Wallace is largely remembered for his theory of evolution through natural selection, which inspired Charles Darwin’s studies. He began his career as a surveyor’s apprentice and later introduced concepts such as reinforcement in animals, also known as the Wallace effect. He was awarded the Order of Merit.

Karl Landsteiner was a physician, biologist, and immunologist. He is credited with distinguishing the main blood groups as well as identifying the Rhesus factor. He is also credited with discovering the polio virus along with Erwin Popper and Constantin Levaditi. He won the Aronson Prize in 1926. In 1930, Landsteiner was honored with the Nobel Prize in Physiology or Medicine.

Theodor Schwann was a German physiologist and physician best remembered for his important contributions to biology. He is credited with discovering the Schwann cells, which is named after him. He is also credited with discovering pepsin and the organic nature of yeast. Theodor Schwann also invented the term metabolism.

A scientist, meteorologist, mathematician, and biologist, Gregor Mendel is considered the founder of the modern science of genetics. He conducted a series of experiments on pea plants between 1856 and 1863, establishing many rules of heredity. Besides his work on pea plants, he also described novel plant species and conducted experiments with hawkweed and honeybees.

Indian physicist, biologist, and plant physiologist Jagadish Chandra Bose revolutionized science with his research on how plants and animals react to external stimuli. He founded the Bose Institute, made pioneering contribution to the field of radio and microwave optics, and also penned one of the first works of Bengali science fiction.

British geneticist J.B.S. Haldane is remembered for his pioneering use of statistics in biology. A proponent of neo-Darwinism, he was the son of physiologist John Scott Haldane and had begun assisting his father at age 8. He later joined the British Communist Party and also moved to India.

Thomas Hunt Morgan was an evolutionary biologist, geneticist, and embryologist. He won the Nobel Prize in Physiology or Medicine in 1933. He worked extensively on the role that the chromosome plays in heredity and demonstrated that genes are carried on chromosomes. In his later career, he established the division of biology at the California Institute of Technology. 

John Muir was a Scottish-American naturalist, environmental philosopher, glaciologist, botanist, zoologist, and author. Nicknamed Father of the National Parks and John of the Mountains, Muir was an influential proponent of the preservation of wilderness in the US. He is credited with co-founding the American conservation organization, The Sierra Club. Muir is considered a hero by many environmentalists around the world.

Louis Agassiz was a biologist and geologist. He was famous as a scholar of Earth's natural history. Born in Switzerland, he completed his education in Europe and emigrated to USA. He was appointed a professor of zoology and geology at Harvard University. He later founded the Museum of Comparative Zoology at the Lawrence Scientific School.  

Robert Koch was a German microbiologist and physician. One of the prominent co-founders of modern bacteriology, Koch is credited with creating and improving laboratory techniques and technologies in the field of microbiology. He is also credited with making important discoveries in public health. In 1905, Robert Koch won the Nobel Prize in Physiology or Medicine for his research on tuberculosis.

Alfred Kinsey was an American biologist, sexologist, and professor of zoology and entomology. He is credited with founding the Indiana University's Institute for Sex Research in 1947. Kinsey's research on human sexuality and his other works have influenced cultural and social values in the USA as well as internationally. In 2012, Kinsey was inducted into Chicago's Legacy Walk.

Rudolf Virchow was a German physician, pathologist, anthropologist, biologist, prehistorian, editor, writer, and politician. Nicknamed the Pope of medicine by his colleagues, Virchow is credited with founding the field of social medicine. He is also widely regarded as the father of modern pathology.  Rudolf Virchow was the first person to name diseases, such as thrombosis, leukemia, ochronosis, embolism, and chordoma.

Ernst Haeckel had initially practiced medicine before he gained an interest in Charles Darwin’s theory and began exploring zoology and related fields. He not only coined terms such as ecology, but also named numerous species and created a genealogical tree. He drew numerous figures of animals and sea creatures, too.

French biologist Jean-Baptiste Lamarck acquired his love for plants while serving as a soldier in the French army. Following an injury, he quit his military career but retained his love for botany. He later taught zoology, studied the classification of invertebrates, and also coined the term biology.

German scientist Paul Ehrlich is remembered for his contribution to immunology, which also won him a Nobel Prize. Known as the pioneer of chemotherapy, he also discovered the first-known treatment of syphilis. Born into a business family, he was introduced to the method of studying cells by his pathologist uncle.

Thomas Henry Huxley was an English biologist and anthropologist. He specialized in comparative anatomy and was a proponent of Charles Darwin's theory of evolution. Despite having little formal schooling, he went on to become one of the finest comparative anatomists of the 19th century. He was the chair of natural history at the Royal School of Mines for 31 years. 

Ronald Fisher was a British polymath, statistician, geneticist, mathematician, and academic. He is credited to have single-handedly created the foundations for modern statistical science. He made important contributions to the field of genetics and is known as one of the three principal founders of population genetics. He was elected to the Royal Society in 1929. 

British surgeon Joseph Lister was a pioneer of antiseptic medicine usage and made a huge contribution to the development of preventive medicine for bacterial infection. His achievements have been honored by many, such as the makers of Listerine antiseptic and mouthwash, who named their product after him.

A pioneer of molecular biology, Oswald Avery revolutionized science with his research on the chemical processes involved in immunology. The Canadian-American bacteriologist initially aspired to be a musician. He later proved that DNA was the basis of heredity. Though nominated for the Nobel Prize multiple times, he never won it.

Nettie Stevens was an American geneticist. She is credited with discovering sex chromosomes which later came to be known as the X and Y chromosomes. In 1994, Nettie Stevens was inducted into the National Women's Hall of Fame.

Trofim Lysenko was a Soviet biologist and agronomist. Lysenko was one of the most influential supporters of Lamarckism. He also condemned Mendelian genetics and supported Lysenkoism, a political campaign that rejected natural selection. Lysenko used his political power to imprison his critics. Several Soviet scientists, including Nikolai Vavilov, who failed to renounce genetics were either imprisoned or killed.

Howard Florey was an Australian pathologist and pharmacologist. He is best remembered for his role in the formation of penicillin, for which he shared the prestigious Nobel Prize in Physiology or Medicine with Alexander Fleming and Ernst Chain in the year 1945. Florey is credited with carrying out the first clinical trial of penicillin at the Radcliffe Infirmary in 1941.

Claude Bernard was a French physiologist whose scientific experiments led to several important discoveries. He is credited with coining the phrase milieu intérieur, which refers to the extracellular fluid (ECF) environment. He also pioneered the use of a blinded experiment to eliminate various experimental biases.

Nobel Prize-winning cytologist and physician Camillo Golgi is remembered for his contribution to the study of the central nervous system. He revolutionized medical science with his staining technique and discoveries such as the Golgi cell, the Golgi tendon organ, and the Golgi apparatus, apart from his research on malaria.

Apart from being a sociologist and biologist, Patrick Geddes was known for his impeccable sense of town planning. While he initially taught botany in Dundee, he later turned to sociology and conducted studies in India, Mexico, and other countries. He was eventually knighted for his achievements.

Karl Patterson Schmidt was a herpetologist. He studied biology and geology at Cornell University and realized his keen interest in herpetology. He later worked as a scientific assistant in herpetology at the American Museum of Natural History. He undertook many collecting expeditions for the Field Museum of Natural History in Chicago. He died after being bitten by a boomslang snake. 

British biologist Ian Wilmut revolutionized embryology by leading the team of researchers who successfully created the first cloned mammal, the sheep named Dolly. A leading proponent of cryopreservation, he also implanted the first calf embryo, Frostie, in a surrogate cow. He was later knighted for his achievements.

Carl Akeley was an American taxidermist, biologist, sculptor, conservationist, nature photographer, and inventor. Widely regarded as the father of modern taxidermy, Akeley is remembered for his immense contributions to American museums, such as the American Museum of Natural History, the Field Museum of Natural History, and the Milwaukee Public Museum. He is also credited with founding the AMNH Exhibitions Lab.

Charles Davenport was a prominent biologist and eugenicist who played an influential role in the American eugenics movement. He earned a Ph.D. in biology and ventured into an academic career. He pioneered new quantitative standards of taxonomy and earned much prominence as a biologist. He later founded the Eugenics Record Office and the International Federation of Eugenics Organizations (IFEO).