25 Mind-Blowing Biology Breakthroughs That Shaped Our World!

Biology Discoveries

Top Biology Discoveries: Biology is an incredibly diverse science. It studies life from the most microscopic beings such as viruses and bacteria to the megafauna of deep history. Specialists in molecular biology can create a new life from scratch and edit existing genomes.

However, to get to this point, several important inventions and discoveries had been made, and several important theories formulated.

Top 25 Biology Discoveries

Here are the top 25 biology discoveries of all time.


First compound microscope.

Who When What
Hans and Zacharias Janssen 1590 First compound microscope

Zacharias JanssenThe father and son team from German town Middleburg have placed two spectacle lenses into a tube, one above the other and found out that such an instrument helps see microscopic objects.

  • Some of their microscopes even had three lenses and considerable magnification, even if the images were unclear.
  • Their invention significantly impacted the development of science. Without the microscope, it would have been impossible to study cells, small animals, or bacteria.


Blood circulation in animals.

Who When What
William Harvey 1628 The first description of blood circulation in animals

William HarveyWilliam Harvey was a British doctor. He has performed multiple dissections on dogs.

  • He also had demonstrated his experiments before the other surgeons. Harvey has shown that the blood circulates in two loops: pulmonary and systemic.
  • He has also discovered valves in veins and determined that blood can only move in specific directions in the body.
  • He has published his findings in a book called “Anatomical Study of the Motion of the Heart and of the Blood in Animals“.
  • Understanding how our blood vessels work was crucial for medicine and physiology. It has impacted treatments of the time and raised the interest in anatomy.


The first description of cells.

Who When What
Robert Hooke 1665 The first description of cells published.

Hooke MicroscopeRobert Hooke was an accomplished inventor and scientist, a member of the Royal Society of London.

  • He has improved the microscope made by Janssens and was the first person in history to describe cells in plant tissue.
  • He has also depicted many other vital structures of plants, insects, and other animals.
  • Hooke’s discoveries have started a trend in using microscopes for life studies, which have eventually led to multiple crucial discoveries.
  • He has also become an example of proper scientific inquiry and high-quality scientific drawing.
  • It would not have been possible to formulate the cell theory without Hooke’s discovery either.


Discovery of Microorganisms.

Who When What
Antonie van Leeuwenhoek 1676 Discovery of microorganisms.

Antonie Van LeeuwenhoekLeeuwenhoek has built his own small microscope and with its help has studied life histories of insects and microscopic organisms, such as protozoa and bacteria.

  • He was also the first to show that microscopic organisms, which he has called animalcules, were present in water, on various surfaces, as well as foodstuffs.
  • His discoveries were the start of microbiology and entomology. Without his work, people would not know that microorganisms cause illnesses and contamination.
Suggested Reading: History of Microbiology


Classification of life.

Who When What
Karl Linnaeus 1758 A first universal classification system of living beings was proposed.

Karl LinnaeusKarl Linnaeus, a Swedish scientist, has proposed a universal system of classification of living beings.

  • The new system was hierarchical, Latin-based, and allowed easy communication between scientists.
  • Each species was given a unique binomial name and belonged to a particular genus, family, order, class, and kingdom.
  • Linnaeus system has been modified several times since then, but the initial idea still remains the same.
  • The existence of the classification system has made the study of life significantly easier and also allowed to study evolutionary relationships between organisms in later centuries.


Bacteria are not a product of a spontaneous generation.

Who When What
Lazzaro Spallanzani 1768 The spontaneous generation theory is disproved.

Lazzaro SpallanzaniThe experiment carried out by an Italian abbot and professor, Lazarro Spallanzani, has proven that microbes are not created through non-living “life force”, but can only come from other microorganisms.

  • This experiment has helped people admit that all animals, without exception descend from other animals of the same type, overthrowing the previously popular “spontaneous generation” theory.
  • Spallanzani’s experiment has contributed to our understanding of the role of microorganisms and where they come from.
  • It was also the basis for the pasteurization method, later developed by Pasteur.


Cell theory.

Who When What
Theodor Schwann, Matthias Schleiden, Rudolf Virchow 1838 and 1858 The establishment of cell theory.

Theodor SchwannTheodor Schleiden, an animal specialist, and Matthias Schleiden, a botanist has come to the common conclusion: all living beings consist of units with similar shape and structure – cells.

They have formulated the cell theory:

  • All living beings are made of cells.
  • Each cell is a functional unit and a building block.

Later in 1858, an outstanding German anatomist postulated a third important rule to the cell theory: all cells descend from other cells. The formulation of the cell theory was the start of cell biology as we know it. Without it, we would not understand many processes and certainly would not be able to fight such diseases as cancer.

Suggested Reading: History of Cell Biology


Germ theory.

Who When What
Louis Pasteur 1861-1862 Microbes were proven to be responsible for illnesses.

Louis PasteurLouis Pasteur, a French microbiologist, and chemist is considered the father of modern microbiology.

  • His work was extremely extensive. His most notable achievements are proving beyond doubt that bacteria caused illnesses and the invention of pasteurization based on earlier Spallanzani’s experiment.
  • We rely on pasteurization up to this day to preserve our food. Without vaccines and culture methods developed by Pasteur, we would not have been able to fight diseases of cattle and humans.


Theory of Evolution.

Who When What
Charles Darwin And Alfred Wallace 1859 Evolution theory.

Charles DarwinThe British scientists Charles Darwin and Alfred Wallace has independently formulated a theory that explained the origins of life on Earth and mechanisms of evolution of species.

  • Evolutionary theory has expanded dramatically since Darwin’s time, but the existence of natural selection is virtually undisputed up to this day.
  • Darwin’s work has contributed significantly to our understanding of life on Earth and the processes that are still taking place today.
Suggested Reading: History of Evolution


The laws of heredity.

Who When What
Gregor Mendel 1866 Discovery of the mechanisms of heredity.

Gregor MendelGregor Mendel, an Austrian monk, and a mathematician have postulated the mechanisms of transferring inherited traits from parents to offspring.

  • He has used pea plants for his experiments and has discovered the existence of dominant and recessive alleles.
  • Mendelian genetics is only one aspect of the complex mechanism of inheritance. However, it still plays a massive role in breeding programs in agriculture and understanding human disorders.
  • Mendel also introduced statistics as a method of evaluating results and drawing conclusions, which is now widely used in all sciences.
Suggested Reading: History of Genetics



Who When What
lya (Elie) Ilyich Mechnikov 1883 Discovery of phagocytosis.

Ilyich MechnikovIlya (Elie) Mechnikov has discovered the existence of specialized cells in animals (both vertebrate and invertebrate) that were responsible for eliminating pathogens and dead cells.

  • ‘Mechnikov’s discovery has started immunology – the science devoted to the study of defense mechanisms against pathogens inside the body.
  • Immunology helps significantly in our fight against pathogens and vaccine development.


Chromosomes and their role in fertilization.

Who When What
Edouard van Beneden 1883 Discovery of chromosomes.

Edouard Van BenedenEdouard van Beneden, a Belgian embryologist and cytologist, has published several papers since 1883, describing chromosomes in the Ascaria worms eggs, as well the processes of fertilization and mitosis.

Without his discoveries, the next breakthroughs in understanding heredity in general and chromosome disorders, in particular, would have been impossible.


Tobacco mosaic virus.

Who When What
Dmitriy Ivanovsky 1892 The first description of tobacco mosaic virus.

Mmitriy IvanovskyThe Russian scientist Dmitriy Ivanovsky was studying tobacco plants that were affected by the illness called tobacco mosaic.

  • He has proven that the illness was caused by an agent far smaller than regular bacteria.
  • The actual term, “virus“, was coined later by Martinus Beijerinck in 1898.
  • Due to the elegant experiment carried out by Ivanovsky, the scientific community has learned about viruses even though they could not really see them until the invention of the electron microscope.


Inheritance of alkaptonuria.

Who When What
Archibald Garrod 1902 Inheritance of alkaptonuria established.

Archibald Edward GarrodArchibald Garrod has studied family charts of patients with a metabolic disorder – alkaptonuria and has figured out that this illness is inherited according to Mendelian laws.

  • It was the first description of an inheritable disease and the additional proof of the universality of Mendelian laws.
  • Due to Garrod’s discovery, specialists could better understand the causes of diseases, such as hemophilia.


Bacterial transformation.

Who When What
Frederick Griffith 1928 Discovery of bacterial transformation.

Frederick GriffithWhile experimenting with two bacterial strains of Staphylococcus pneumonia, Griffith has discovered that the traits from the dead bacteria can be transferred into living ones.

  • This process was called transformation. Griffith’s discovery helped establish the role of DNA in heredity.
  • The discovery of transformation and bacterial plasmids has also influenced the development of genetic engineering.
  • Due to our knowledge of bacterial transformation, we can also understand how antibiotic resistance is spread in bacterial populations.


Antibiotic penicillin.

Who When What
Alexander Fleming 1928 Discovery of penicillin.

Alexander FlemingAlexander Fleming was working at St. Mary’s hospital in London, Great Britain.

  • He has accidentally discovered that the presence of certain types of molds in Petri dishes of bacterial cultures kills the bacteria.
  • He has also purified the substance responsible for this effect. Though penicillin was discovered in 1928, its production as a drug had not started until the 1940s, when proper antibacterial care was crucial for wounded soldiers.
  • The discovery of penicillin was the start of the antibiotic era, decreasing mortality from illnesses worldwide.


DNA methylation.

Who When What
Rollin Hotchkiss 1948 Discovery of DNA methylation.

Rollin HotchkissWhen Hotchkiss was studying a preparation of calf thymus, he has discovered that one of the DNA Nucleotides, cytosine, had an additional methyl group – was methylated.

  • Later, it was found that other nucleotides could be methylated, too.
  • DNA methylation is one of the most common mechanisms of regulation of gene activity.
  • We now know that this type of regulation called epigenetic regulation is crucial for our development and well-being.


Protein structure.

Who When What
Linus Pauling 1950 Protein structure discovered.

Linus PaulingUsing the data obtained from X-Ray crystallography and paper models, Linus Pauling has discerned how amino acids fit together to form proteins.

  • He described the first structure as the protein alpha helix. Proteins play major roles in the functioning of cells and complex organisms, and determining their formation was the first step to understanding their activity.
  • Pauling’s method has also influenced Watson and Crick and helped establish the DNA structure.
  • Pauling’s discovery is now considered the start of molecular biology. Pauling was awarded a Nobel Prize in chemistry in 1954.


Mobile genetic elements.

Who When What
Barbara McClintock 1950 Discovery of mobile genetic elements.

Barbara McclintockAn American scientist, Barbara McClintock, was studying plants. Her particular area of interest was the mechanism of breaks in the chromosomes of the maize plants.

  • She has discovered that there are areas in the chromosomes that can break away and re-insert themselves in other regions.
  • This was one of the most astonishing discoveries of the 20th century, upending the scientist’s understanding of how the genome works and how mutations are generated.
  • In later decades, it was found that mobile genetic elements (transposons) can be present in all living organisms, from viruses to mammals.


DNA structure.

Who When What
James Watson and Francis Crick 1953 Discovery of the DNA structure.

James Watson And Francis CrickBased on data on the ratio of nucleotides and X-ray images made by another scientist, Rosalind Franklin, Watson and Crick have figured the DNA structure.

  • They have shown that DNA is a double spiral with hydrogen bonds between complementary purine and pyrimidine bases.
  • The discovery of DNA structure helped determine the mechanisms of replication, translation, and the DNA code itself.


DNA sequencing method by Frederick Sanger.

Who When What
Frederick Sanger 1977 Sanger sequencing method.

Frederick SangerFrederick Sanger has developed a method that allows determination of the exact sequence of nucleotides in the genome using DNA polymerase, pre-made primers, and radioactive nucleotides.

His method was significantly more straightforward and quicker than previous ones and helped substantially speed up DNA sequencing in bacteria, viruses, and later humans.


The new kingdom of life.

Who When What
Carl Woese 1977 The new kingdom of life discovered.

Carl WoeseCarl Woese was sequencing a specific type of nucleic acid – ribonucleic RNA.

  • He has discovered unicellular organisms without a nucleus with a completely different type of ribosomal RNA than bacteria and eukaryotes.
  • He has shown that those organisms belonged to a completely separate kingdom of life. They were called archaea.
  • modern scientific thought leans towards the idea that eukaryotes actually descended from Archaea through endosymbiosis.


p53 protein.

Who When What
Kress et al. 1979 P53 protein discovered.

P ProteinWhile studying how SV40 virus causes the development of the cancer tumors, Kress and his colleagues discovered a novel protein that was actively produced in the nuclei of cancer cells and was also associated with one of the viral antigens.

  • Later research has uncovered that this protein was crucial in two critical processes: cancer development and programmed cell deathapoptosis.
  • Among other things, p53 was then found to be involved in the cancerogenic effects of smoking.


Genes controlling autophagy.

Who When What
Yoshinori Ohsumi 1992 Discovery of autophagy genes.

Yoshinori OhsumiAutophagy is a process of self-destruction and recycling in the cell in response to stress.

  • Ohsumi has developed a method to study this process in yeast and has managed to find several genes responsible for this process.
  • His work has contributed both to science and medicine, as autophagy was found to play a significant role in neurodegenerative diseases such as Alzheimer’s and Parkinson’s. Ohsumi was awarded a Nobel Prize in 2016 for his work.


Cas9/CRISPR system in bacteria.

Who When What
R. Barrangou et al. 2007 Discovery of Cas9/CRISPR system in bacteria.

CrisprThe team of scientists led by R. Barrangou has discovered that bacteria use special enzymes to cut out pieces of infecting virus that are lately inserted into the bacterial genome.

  • This system helps bacteria recognize viruses in time. Later, the scientists realized that those bacterial enzymes can be used for editing the genomes of other organisms.
  • This discovery was crucial for cancer research and other fields. First, gene editing in humans was also performed using this technique.

The history of biology is full of small and big discoveries that have greatly influenced our lives. These discoveries helped us understand life better and make incredible improvements in medicine.

This biology discoveries list only describes a few that have impacted the development of biology the most.

Cite This Page

BioExplorer.net. (2024, April 13). 25 Mind-Blowing Biology Breakthroughs That Shaped Our World!. Bio Explorer. https://www.bioexplorer.net/top-biology-discoveries.html/.
BioExplorer.net. "25 Mind-Blowing Biology Breakthroughs That Shaped Our World!" Bio Explorer, 13 April 2024, https://www.bioexplorer.net/top-biology-discoveries.html/.
BioExplorer.net. "25 Mind-Blowing Biology Breakthroughs That Shaped Our World!" Bio Explorer, April 13 2024. https://www.bioexplorer.net/top-biology-discoveries.html/.
Key References
  • All images are from Wikimedia under the creative commons licenses.
  • “Who Invented the Microscope?”. Accessed July 11, 2019. Link.
  • “Throughout history, key discoveries have changed the course of medical science. We look at four historic medical breakthroughs.”. Accessed July 11, 2019. Link.
  • “Micrographia by Robert Hooke, 1665 – The British Library”. Accessed July 11, 2019. Link.
  • “Discovery Of Bacteria – by Antony van Leeuwenhoek”. Accessed July 11, 2019. Link.
  • “Carolus Linnaeus | Swedish botanist | Britannica.com”. Accessed July 11, 2019. Link.
  • “[Lazzaro Spallanzani and his refutation of the theory of spontaneous generation]. – PubMed – NCBI”. Accessed July 11, 2019. Link.
  • “Attempts to prevent illness and disease WJEC – Revision 5 – GCSE History – BBC Bitesize”. Accessed July 11, 2019. Link.
  • “BBC – iWonder – Charles Darwin: Evolution and the story of our species”. Accessed July 11, 2019. Link.
  • “Mendel’s principles of inheritance Science Learning Hub”. Accessed July 11, 2019. Link.
  • “Ilya Mechnikov – Biographical – NobelPrize.org”. Accessed July 11, 2019. Link.
  • “Edouard van Beneden | Belgian embryologist and cytologist | Britannica.com”. Accessed July 11, 2019. Link.
  • “Dmitri Ivanovsky – Scientist of the Day – Linda Hall Library”. Accessed July 11, 2019. Link.
  • “Martinus W. Beijerinck | Dutch microbiologist and botanist | Britannica.com”. Accessed July 11, 2019. Link.
  • “Sir Archibald Edward Garrod :: DNA from the Beginning”. Accessed July 11, 2019. Link.
  • “Transforming Principle – Griffith’s Experiment About Genetics”. Accessed July 11, 2019. Link.
  • “Alexander Fleming Discovery and Development of Penicillin – Landmark – American Chemical Society”. Accessed July 11, 2019. Link.
  • “Epigenetics | Summary”. Accessed July 11, 2019. Link.
  • “Remembering Rollin Hotchkiss (1911–2004)” – Genetics. Accessed July 11, 2019. Link.
  • “Linus Pauling: Discovering Protein “. Accessed July 11, 2019. Link.
  • “Linus Pauling – Facts – NobelPrize.org”. Accessed July 11, 2019. Link.
  • “Barbara McClintock and the discovery of jumping genes | PNAS”. Accessed July 11, 2019. Link.
  • “The discovery of DNA | Stories | yourgenome.org”. Accessed July 11, 2019. Link.
  • “The sequence of sequencers: The history of sequencing DNA”. Accessed July 11, 2019. Link.
  • “Initial sequencing and analysis of the human genome | Nature”. Accessed July 11, 2019. Link.
  • “Archaea and the origin of eukaryotes | Nature Reviews Microbiology”. Accessed July 11, 2019. Link.
  • “The history of p53”. Accessed July 11, 2019. Link.
  • “Smoking, p53 mutation, and lung cancer. – PubMed – NCBI”. Accessed July 11, 2019. Link.
  • “The 2016 Nobel Prize in Physiology or Medicine – Press release – NobelPrize.org”. Accessed July 11, 2019. Link.
  • “CRISPR Provides Acquired Resistance Against Viruses in Prokaryotes | Science”. Accessed July 11, 2019. Link.
  • “The CRISPR-baby scandal: what’s next for human gene-editing”. Accessed July 11, 2019. Link.


Please enter your comment!
Please enter your name here