Ten Famous Biologists Who Changed Their Field of Study Forever

Biologist testing something using a glass and a test tube

Biology is one of the most interesting and diverse fields of science, and there have been many famous biologists. Biology is a natural science that focuses its study on life and living organisms, and biologists often specialize in a specific aspect of life, such as studying a particular organism or aspect of life such as hereditary or evolution.

There have been many luminaries in the biological sciences who have advanced our knowledge of the natural world and our place in it. It's difficult to produce a list of the top 10 most famous biologists, but each person on the following made significant contributions to their field that are still being felt to this day.

Our List of 10 Famous Biologists

  • Aristotle
  • Rachel Carson
  • Gregor Mendel
  • Andreas Vesalius
  • Charles Darwin
  • Louis Pasteur
  • Antonie van Leeuwenhoek
  • Alexander von Humboldt
  • Carl Linnaeus
  • Joseph Lister


Aristotle was an ancient Greek philosopher and is best known as the father of Western Philosophy along with his teacher Plato, and as one of the earliest famous biologists of recorded history. His influence on the physical sciences is almost as great as his influence on philosophy and he pioneered the study of biology from a systematic perspective. He spent two years observing and writing about the zoology of the island of Lesbos and its surrounding seas.

Among his observations, Aristotle described the sea life captured by the islands fishermen including electric rays, frogfish and catfish. When it came to cephalopods, such as the paper nautilus and the octopus, he was the first to describe the use if the hectocotyli arm in sexual reproduction, a view that scientists discounted until the 19th century when it was observed again.

Aristotle noted that an animal's structure matched its function. For example, he described how Herons, marsh-dwelling birds, have long necks and legs, perfect for walking and hunting in the mud, while ducks swim and have short legs with webbed feet. In his studies, he distinguished around 500 species of animals, arranging them in his History of Animals, and he called this system the ladder of life. The different classifications he placed animals in are the precursor of the scientific classification still used today that was created by another member of of our famous biologists list, Carl Linnaeus.

Rachel Carson

Rachel Carson is a famous biologist, specifically a marine biologist, and author who was a pioneer of the Environmentalist movement. In the 1950s she began research on the ecology and organisms of North America's Atlantic Shore. While performing this research, she observed that synthetic pesticides that were being widely used at the time to eradicate insects such as the Gypsy Moth were having negative effects on the environment.

Carson used her findings on the environmental damage caused by synthetic pesticides such as DDT for her most famous book, Silent Spring. She gathered examples of the damage caused by the use of DDT despite the fact that her research was opposed by many powerful organizations from chemical companies to the United States government's own researchers.

In Silent Springs, Carson labeled pesticides as biocides as their effects were not limited to the invasive or harmful species they targeted, and they instead caused widespread damage to the other organisms in the ecosystem. When the book was released, it sparked interest in protecting the environment and led to the founding of the Environmental Protection Agency in 1970.

Gregor Mendel

Considered the father of genetics, Gregor Mendel was in Augustine Friar and scientist in the 19th century. He performed studies on the pea plant that included experiments that established many of the rules of heredity and gave future generations better understanding of crossbreeding in animals and plants, allowing them to favor certain desirable traits and places him on our list of famous biologists.

Known today as the laws of Mendelian Inheritance, he determined that some traits were dominant and others regressive. Take, for example, seed color. When Mendel crossbred a true-breeding yellow pea with a true-breeding green pea, the offspring produced yellow peas because the yellow pea trait was dominant. In the next generation, one out of four of the green pea producing plants produced yellow peas, because of the recessive gene.

The true significance of Mendel's discovery wasn't appreciated until well into the 20th century because it was so controversial during his lifetime, so it was largely ignored at the time. Once it was re-discovered, it became a cornerstone of the study of genetics and evolution. On a more practical side, it enabled the understanding of crossbreeding and led to the development of heartier and healthier lines of vegetables and fruit that we see in our supermarkets today.

Andreas Vesalius

Andreas Vesalius was a Flemish physician and anatomist. His study of the human body led to his influential book on human anatomy: On the Fabric of the Human Body. This book became so influential that Vesalius is considered the father of modern human anatomy, which landed him a spot on our list of 10 of the world's most famous biologists.

Vesalius had a prestigious medical career, and he traveled throughout Italy with priests to help those afflicted with Hanson's Disease, more commonly known as leprosy. At the time, most of the knowledge of human anatomy came from animal observations as religious laws forbid the study and dissection of human corpses. However, Vesalius performed public dissections, notably on the body of a notorious criminal named Jacob Karrer von Gebweiler following his execution. Vesalius assembled the bones of the skeleton and it is still preserved and on display in the University of Basel.

As with many people on this list of famous biologists, his impact wasn't fully known at the time of his death. His findings bucked the traditional views of anatomy that had existed for centuries and those views persisted during his lifetime and afterward. Centuries later, when the study of anatomy became more established and easier to perform, his views, based on his own experimentation and observation became the foundation for modern anatomy.

Charles Darwin

Charles Darwin, one of the most famous biologists to hail from Britain, is known as the father of evolution for his 1859 book On the Origin of Species. Darwin performed the research for this book while working as a naturalist on the HMS Beagle on its round the world voyage from 1831 to 1836. Most of Darwin's observations on the journey were surveying and charting the coastlines, but it was at the Galapagos Islands where he made his biggest contribution to biology and solidifying his place among the world's most famous biologists.

The Galapagos Islands are a small chain of islands off the coast of South America, and when the HMS Beagle arrived, Darwin noticed that several similar species had different characteristics depending on which island they lived on. He's known for his work observing 15 different species of finches, small birds that had different sized and shaped beaks that evolved to fit their environment. This helped Darwin come up with his theory of natural selection.

Natural selection is the cornerstone of modern biology, and Darwin postulated that random mutations arise in the genome of individual organisms. The offspring of these organisms inherit these and when these traits enable the offspring to better survive and pass on its genes the mutated organism survives and differentiates itself from the original. However, Darwin's theory of evolution is still controversial to this day among certain religious groups, but the scientific community generally accepted it during his lifetime.

Louis Pasteur

The French biologist and chemist Louis Pasteur is best known for his breakthrough discovering the causes of diseases and preventing their spread. Besides that, he invented pasteurization, the technique for treating milk and other liquids to prevent bacterial contamination. He is known as a father of microbiology, and because of the prevalence of pasteurization in today's world, of all the famous biologists on the list, Pasteur is one of the most impactful scientists of the modern era.

While germ theory is an accepted part of modern science, in Pasteur's time, it was believed that diseases came from a miasma, or bad air, and spontaneous generation. While other scientists had theorized about germs prior to Pasteur, his revolutionary work showed the first proof that many diseases resulted from bacteria or viruses and not spontaneous generation.

Pasteur showed this by doing fermentation experiments. The skin of grapes contains natural yeasts that enable the grape juice to be turned into wine, so Pasteur sterilized grapes and grape juice and showed that it would not ferment because of the lack of yeasts. Many of these experiments used heat to sterilize the grape juice, and this became the basis of pasteurization. Because of pasteurization, the shelf life of many foods has been greatly extended. This has vastly improved the safety of the food supply and cut down on the spread of many diseases, saving thousands of lives in the process.

Antonie van Leeuwenhoek

A Dutch scientist and businessman, Antonie van Leeuwenhoek lived during the Golden age of Dutch science and technology. He is known as the father of microbiology for his pioneering microscopes and discovery of microbes, even though he was a self-taught scientist. While working in a drapery shop, van Leeuwenhoek became interested in the possibility of using magnifying glasses to better judge the quality of the threads in his drapes. This led to an interest in developing his own microscope. By the time his death, he had created at least 25 single lens microscopes.

The discovery of microbes came with his examination of pond water with one of his microscopes. He discovered the large amounts of tiny organisms that inhabit even a drop of water. He referred to these as Animalculum, or tiny animals, in Latin. With further experiments, he became the first person to observe and document the microscopic view of bacteria, crystals, red blood cells, muscle fibers, and more.

As opposed to most scientists in their discoveries, he did not publish his own papers. The information known about his work came from letters he sent to the Royal Society in London. This gave him fame, and since he used his own designs for microscopes, he had a veritable monopoly on microbiology during his lifetime. Ever the businessman, he worried that if others understood the ease in which he made his microscopes, they would forget about his discovery, but today, microscopes are ubiquitous to the scientific community.

Alexander von Humboldt

Alexander von Humboldt was a German explorer and naturalist who laid the foundation for the field of biogeography, the study of how species in ecosystems are distributed worldwide and through time. Through his studies, he became the first person to describe the effects of human-induced climate change. His background in biogeography came from his desire to find a unified theory of nature that combined biology, geology, and meteorology.

Building upon this work, scientists have been able to trace the movement of different species and use that information to learn much more about our world. An example of this is continental drift. The earth's surface is made up of several tectonic plates, and many theorized that the continents had, in the distant past, been one giant continent known as Pangaea. The study of biogeography has shown the distribution of fossil records of the same species in far-flung continents to support this theory.

Another important contribution to biology and to science that came from Alexander von Humboldt's work is the 19th-century movement called Humboldtian science. Using Humboldt's methods and following his general ethics for scientific exploration, several of the most important 19th-century scientific luminaries including Charles Darwin, Sir Edward Sabine, and Charles Lyell made huge leaps in human knowledge. Because of this, almost all scientific discovery after Humboldt is due in part to his influence, and he earned a place on our list of famous biologists

Carl Linnaeus

A botanist and zoologist from Sweden, Carl Linnaeus developed the system for naming and organizing living organisms that we still use today. Because of this and his other scientific discoveries, he is known as the father of modern taxonomy and the father of modern ecology. It was not until Linnaeus developed his taxonomy that there was a universally accepted way to classify living organisms. Linnaean taxonomy classifies animals and plants into kingdoms, classes, orders, genus and finally species, which shows how different organisms are related to one another.

These concepts allowed later scientists to build upon Linnaeus's work and look at the taxonomy of evolution. Later scientists had modified and added to Linnaeus's classifications to include new kingdoms of organisms such as fungi, Monera, and protozoa. Even today, when new species are discovered, Linnaean taxonomy is used to classify them.

Linnaean taxonomy has also been applied to the evolution of human beings. Linnaeus classified humans under primates in his first version of his taxonomy. This was controversial at the time because of the belief that human beings were separate from the animal kingdom, but it led to other scientific discoveries of the origin of the human species.

Joseph Lister

Joseph Lister was a British surgeon who was a pioneer of antiseptic surgery. Prior to the acceptance of germ theory, many physicians did not know the link between microorganisms and disease. Because of this, there was little attempt to clean their hands or instruments before they performed surgery. This resulted in many infections after surgeries that led to the death of many patients. Lister introduced the use of carbolic acid for the cleaning of wounds and the sterilization of surgical instruments, which led to a reduction in post-operative infections and earned Lister the moniker of the father of modern surgery.

Prior to Lister's discoveries, most surgeries were performed under very unsanitary conditions. Surgeons would often leave their operating gowns unwashed, displaying the stains as a display of experience. Hospitals didn't even have facilities for washing hands or patients wounds before Lister's insistence that it would make a difference in the number of patients who contract a deadly infection.

Lister developed his antiseptic carbolic acid solution by testing Pasteur's findings. He performed human testing on a seven-year-old boy who suffered a compound fracture from a cart accident. By covering the boy's wounds with lint dipped in his carbolic acid solution, the boy remained infection free. From his research, he instructed surgeons to wear clean gloves and wash their hands before and after each surgery.


biologist examining something in a microscope

Image source: Pixabay

Looking over our list of 10 of the most famous biologists, we hope you can see the great advancements to science these people brought about. The interconnection between their work is another aspect that should be apparent as all great scientists build on the work of great scientists who came before them. None of the people on this list of famous biologists could have made the discoveries and theories they are most famous for without the work of others, so keep that in mind as you look to a potential career in biology. Remember the great minds of the past and use their work to work on the next big discovery!

Featured Image by PublicDomainPictures from Pixabay

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