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Charles Darwin publishes The Origin of Species.
Darwin proposes a theory about evolution. He says that evolution occurs because of the process of natural selection and that living things pass their characteristics through generations. -
Gregor Mendel discovers the fundamental laws of inheritance
Through an experiment with pea plants, he was the first person to discover the way characteristics are passed down the generations. -
Friedrich Miescher identifies "nuclein"
He discovered in the nuclei of human white blood cells what he called "nucleic". Now, this "nucleic" is known as deoxyribonucleic acid (DNA) -
Chemical composion of DNA
In 1910, Phoebus Levene publishes his tetranucleotide hypothesis: DNA is composed of equal amounts of adenine, cytosine, guanine, and thymine bases. -
Genes are located linearly along chromosomes.
Thomas Hunt Morgan confirms that genes are located linearly along chromosomes. -
Bacterial Transformation
Frederick Griffith reported the first demonstrations of bacterial transformation, but he doesn't discover how it happens. -
Components of DNA
Phoebus Levene discovers deoxyribose sugar in nucleic acids. Later he demonstrates that DNA is made up of nucleotides, which are composed of a deoxyribose sugar, a phosphate group, and a base. -
DNA as the 'transforming principle
By the 1940s it is now known that chromosomes are the vectors of heredity. But, it wasn't until 1944 that DNA was identified as the carrier of genes. This was due to the experiments of Oswald Avery, Colin MacLeod, and Maclyn McCarty. They explain the "how" of the experiments of Frederick Griffith. They suggested that DNA, rather than protein may be the hereditary material of bacteria -
Base pairs discovered
Erwin Chargaff discovers more about DNA composition. He demonstrates that base A complements T and base C complements G. -
Rosalind Franklin photographs crystallized DNA fibres
Rosalind Franklin takes the first X-ray picture of DNA. She takes the famous 51 photo that shows the double helix -
The double helix structure of DNA
James Watson and Francis Crick suggested the 3D model of DNA with the double helix because of the photo of Rosalind Franking -
The study of chromosomes as a medical discipline
A copy of chromosome 21 was associated with Down syndrome and this introduced cytogenetics (the study of chromosomes) into the clinical genetic diagnosis. -
DNA sequencing
Frederick Sanger designed the first DNA sequencing method. This method allows the information contained in the DNAs molecules to be read easily and reproducibly. -
PCR
Kary Mullis invented the PCR (Polymerase Chain Reaction). This is a technique for amplifying a DNA sequence by making multiple copies of it. -
The Genome project
The US government makes the Human Genome Project, which aims to sequence all human chromosomes in 15 years -
First human chromosome is decoded
An international team of researchers decoded for the first time the full genetic code of a human chromosome, chromosome 22, which contained 33.5 million chemical components. -
Decoded the genome of the first mammal
The genome (complete set of genetic information in an organism). of the mouse was decoded. This allowed them to compare the human genome with the genome of another mammal. -
Human Genome is finished
The project was completed, spurring meteoric progress in new DNA sequencing technologies. -
Twins
DNA Worldwide and Eurofins Forensic were the first in the world to prove that twins have differences in their genetic makeup.
