The 10 Most Important Breakthroughs in Genetics

The 10 Most Important Breakthroughs in Genetics

Since the Human Genome Project, the field of genetics has expanded rapidly, promoting greater scientific understanding of the link between genes and disease. Let’s take a look at some of the most important discoveries in the field of genetics throughout history.


  1. Charles Darwin publishes On the Origin of the Species (1859)

Darwin established the principle of hereditary traits and natural selection, tracing evolutionary ideas back through history as far as Aristotle. Darwin’s work unified all of the life sciences, explaining the diversity of lifeforms and physiological adaptation to different environments.


Charles Darwin
Image courtesy Gene Wilburn | Flickr


  1. Gregor Mendel establishes the basic principles of genetics (1865)

In a study involving the cross-breeding of pea plants, Mendel discovered that offspring did not have a blend of their parents’ traits, as was the accepted scientific theory at the time. For example, the flowers of the pea plant are either white or purple. When Mendel cross-bred between them, the offspring plant’s flowers were not a blend of the two colors, but distinctly white or purple.

Mendel established that traits pass to future generations through inherited “units,” now known as genes. He further concluded that these traits can sometimes skip generations.


  1. Frederick Miescher isolates DNA for the first time (1869)

Friedrich Miescher was a Swiss medical researcher. He established that “nuclein” (now known as DNA) is comprised of oxygen, hydrogen, nitrogen, and phosphorus. Miescher was the first person to isolate DNA from other cells.


  1. Archibald Garrod establishes the principles of disease inheritance (1902)

Archibald Garrod was an Oxford University professor of medicine. He pioneered the field of metabolic inborn errors.

An effective rediscovery of Mendel’s work occurred at the end of the 1800s, piquing the interest of the world’s leading scientists and increasing understanding of the principles of genetic inheritance. Garrod’s work was focused on applying these principles, not just to physical traits, but to predisposition to disease. Archibald Garrod established the link between genes and disease.


Image courtesy Wikipedia


  1. Alfred Hershey and Martha Chase discover that genes are made of DNA (1952)

Hershey and Chase established in a series of experiments that all of our genetic information is contained in deoxyribonucleic acid, or DNA. Prior to Hershey and Chase’s discovery, scientists incorrectly assumed that proteins were responsible for passing on inheritable information, rather than DNA. Hershey and Chase’s experiments demonstrated that DNA enters host cells, whereas proteins do not.


  1. Francis Crick and James Watson identify the DNA double helix (1953)

Crick and Watson were awarded the Nobel Prize in Medicine for their groundbreaking discovery of DNA’s characteristic double helix structure. Their findings helped scientists to understand the coding of hereditary information and learn how DNA replicates. This led to advancements in molecular biology.


  1. Joe Hin Tjio discovers that human cells have 46 chromosomes (1955)

Born in Indonesia in 1919, this American cytogeneticist revolutionized our understanding of human chromosomes. For almost 50 years, scientists had believed that human beings have 48 chromosomes, a theory Tjio proved was incorrect.


  1. Robert Guthrie develops a genetic screening test (1961)

Robert Guthrie began his career in cancer research. He developed an interest in the prevention of mental disabilities after his son and niece were both diagnosed with phenylketonuria, a rare genetic disease that causes developmental problems.

Studying the disease at the Children’s Rehabilitation Center of Buffalo with Dr Robert Warner, Guthrie found a way of measuring phenylalanine in the blood. Early diagnosis of phenylketonuria is key in improving individual outcomes. Guthrie quickly developed a blood test for newborns.

Known as the “heel prick” test, today millions of newborns worldwide undergo this procedure. It has been adapted to test for a range of genetic conditions.


  1. Marshall Nirenberg cracks the genetic code (1966)

Nirenberg and his team at the National Institutes of Health discovered that all of our genetic information is essentially written in a four-letter alphabet. This scientific breakthrough paved the way for the last and most important event on our timeline.


Marshall Nirenberg
Image courtesy Wikipedia


  1. Scientists sequence the human genome for the first time (2003)

Relying on DNA sequencing techniques developed by Frederick Sanger in the 1970s, the Human Genome Project was an international collaboration between the world’s leading geneticists and was formally launched in 1990. Using Marshall Nirenberg’s cipher, scientists sequenced nucleotide base pairs, effectively creating the first-ever map of a human genome.

Research was conducted in several countries, including France, Germany, the UK, China, and Japan. Additionally, the US government-funded project featured key research from several US institutions.

Originally projected to take 15 years, the Human Genome Project concluded in 2003. By this time scientists had successfully sequenced 92 percent of the human genome. The project effectively revolutionized science—from evolutionary studies to biotechnology—paving the way for huge advancements in numerous scientific disciplines.

Technological breakthroughs have led to a sharp decline in genome sequencing costs. While the Human Genome Project cost an estimated $2.7 billion, today, whole genome sequencing is available for much less.

Dr. Harry Stylli is a healthcare investor and entrepreneur. In his role as chair at OncoCellMDx, Dr. Harry Stylli strives to help physicians not only identify signatures of disease, but also gather crucial information about a cancer’s aggressiveness and staging. Dr. Harry Stylli has provided executive leadership to numerous innovative companies. Dr. Harry Stylli also serves as founder and executive chairman of Progenity, a genetic testing company catering to women and expectant parents as well as to individuals with potential familial cancer risks. You can connect with Dr. Harry Stylli at LinkedIn