The evolution of genetics is a fascinating trajectory spanning thousands of years. From the earliest observations on heredity to modern technological advances in genetic engineering and gene editing. In this article we will look at the evolution of genetics over the course of history.
Genetic selection throughout history
Although genetic selection sounds very recent, it is not. Egyptians and Babylonians (around 1,000 B.C.) were the first to put into practice the artificial selection. They selected the most peaceful animals with the best characteristics to obtain new offspring for their livestock, also transferring this logic to crops.
Over the years and with the knowledge acquired over time, genetic selection techniques have become more sophisticated:
- Artificial selection and selective crosses: are techniques that have been maintained over time, but with important nuances. With the rediscovery of Mendel's laws (1900), geneticists began to apply genetic principles to the selection and crossing of plants and animals.
They are based on an analysis of the genes that allows a better knowledge of the selected parents. Such crosses can also be made between varieties of the same species. - Induced mutagenesisMutations are induced by means of chemicals or radiation. Induced mutagenesis was discovered by Muller in 1927, winning a Nobel Prize in 1946. The aim of this technique is to achieve new characteristics.
- Somaclonal variation: are variations obtained by in vitro cell or tissue culture. The understanding and formal recognition of somaclonal variation as a significant source of genetic diversity in plants dates back to the decade of 1970.
- Genetic engineeringGenetic engineering: this is a highly selective hybridization of traits by manipulation of the genetic sequence in the laboratory. Genetic engineering was born in 1973 with the development of recombinant DNA technology by Stanley Cohen and Herbert Boyer.
Genetic engineering throughout history
Although it emerged in 1973 with the development of recombinant DNA technology, this field has experienced significant evolution. In 1974, Frederick Sanger was a pioneer in validating this technology for the development of modified organisms. However, it was not until the 1980s that the first commercial product, recombinant insulin, was produced, and the first genetically modified crop, insect-resistant Bt corn, was introduced.
With the milestone of complete genome sequencing (2004), genetic engineering continued to evolve until the advent of genetic editing in 2012 with the discovery of CRISPR-Cas. There is still a long way to go, but this technology enables precise and efficient gene editing, facilitating the correction of mutations and genome engineering, developed by Jennifer Doudna and Emmanuelle Charpentier.
DNA discoveries
The above applications would not have been possible without the genetic findings of important scientific events that occurred throughout history:
- Gregor Mendel, the father of genetics: In 1865, Mendel conducted experiments with pea plants and discovered the basic laws of inheritance, describing the segregation and dominance of traits.
- Hugo de Vries, Carl Correns, and Erich von Tschermak: All of Mendel's work went unnoticed until these three scientists rediscovered Mendel's laws in 1900.
- Thomas Hunt Morgan: In 1910, he demonstrated the chromosomal theory proposed by Walter Sutton and Theodor Boveri by identifying the genetic basis of inheritance through experiments with Drosophila melanogaster. This theory proposed that chromosomes are the carriers of genes.
- James Watson and Francis Crick: In 1953, they discovered the double-helix structure of DNA, with crucial assistance from Rosalind Franklin and Maurice Wilkins.
- Frederick Sanger: In 1975, he developed methods for sequencing DNA, known as the Sanger method.
- Barbara McClintock: In 1983, she received a Nobel Prize for discovering the existence of "jumping" genes or transposons in maize, which demonstrated that genes can move within the genome and affect gene expression.
- Kary Mullisinvented the well-known PCR in 1983, a technique that allows the amplification of a specific DNA sequence.
