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Charles Darwin publishes the Origin of Species
Darwin proposed the theory of evolution by the process of natural selection. -
Gregor Mendel discovers the basic principles of genetics
In his paper he shows the action of "invisible" factors in providing for visible traits in predictable ways. The "invisible" trait is genes -
Friedrich Miescher identifies "neclein"
Miescher was the first person to identify what he called the "neclein" which contains DNA. -
The Eugenics Movement
The eugenics movement represents a lack of understanding regarding the discovery of it. Eugenics was first used around 1883 to describe the science of heredity and breeding. -
Mendel's theories are rediscovered by researchers.
Researchers rediscover Mendel's pea plant research. -
Sir Archibald Edward Garrod associates Mendel's theories with a human disease.
Garrod concludes that alkaptonuria was a recessive disease, associating it with Mendel's theories. This discovery helped researchers to develop an understanding of the molecular basis of inheritance. -
Oswald Avery Identifies DNA as the 'transforming principle'
Oswald showed that DNA can transform the properties of cells. This helped to clarify the chemical nature of genes. -
Erwin Chargaff discovers that DNA composition is species specific.
Chargaff discovers that in any double stranded DNA the number of guanine is equal to the number of cytosine and the number of the adenine is equal to the number of thymine. This is called Chargaff's rule. -
Rosalind Franklin photographs crystallized DNA fibers
She produced a high resolution picture of DNA fibers. Using the picture she found out the dimensions of a strand and deduced that phosphates were on the outside of what was a helical structure. -
James Watson and Francis Crick discover the double helix structure of DNA
Watson and Crick discover that DNA is a double helix. They used X-ray data to build a model. Despite the fact that they used the photograph that Franklin had made she did not get honored and could not share the noble prize.