It's National DNA Day! Have you done yours? It was first discovered in 1953. I only remember it being a thing the last 20 years or so. IT amazes me how researchers can even do it.
Every year on April 25 since 2003, scientists, biologists, and genetics enthusiasts come together to observe National DNA Day, celebrating the discovery and research into DNA and the scientific advancements that helped make progress possible. Organized annually by the Human Genome Research Institute, National DNA Day encourages people to learn more about the science that makes them genetically unique.
On April 25, 1953, molecular biologist James Dewey Watson’s academic paper presenting DNA’s double-helix structure (which he co-authored with British molecular biologists Francis Crick and Maurice Wilkins) was published in the scientific journal, Nature. Nine years later, the three scientists were awarded the Nobel Prize in Physiology or Medicine for unearthing the molecular structure of nucleic acids and its importance for genetic information transfer in living beings.
On April 14, 2003, the Human Genome Project, an international scientific research project with the goal of determining the base pairs that make up human DNA and identifying all genes of the human genome, was declared complete. The project lasted for 13 years, finishing two years ahead of schedule, and was publicly funded by the U.S. government. It originally set to map the nucleotides contained within a human haploid genome, but scientists quickly realized that the genome of any given individual is completely unique, so mapping the human genome involved mapping the DNA of a small number of individuals and then piecing them all together to create a complete sequence for each individual chromosome. Meaning the complete human genome is more-so a mosaic rather than representative of any one individual.
Following the completion of the Human Genome Project, both the Senate and the House of Representatives proclaimed April 25, 2003 DNA Day and April as Human Genome Month. The day marked 50 years since Watson, Crick, and Wilkins’ academic paper was published and the month itself was considered significant in genome discovery. However, they only declared it a one-time celebration rather than an annual holiday. Since then, National DNA Day events and celebrations have been hosted by the National Human Genome Research Institute in order to encourage further research as well as celebrate and continue to acknowledge all of the hard work that has been dedicated to the study of DNA.
25% genetically similar
On average, siblings who share the same mother and father — excluding identical twins — appear to be 25% genetically identical and 50% half identical. This occurs because each child gets 50% of their genetic makeup from their mother and 50% from their father, meaning 25% from each has the potential to be genetically identical while the other 50% is a slightly different genetic pattern passed on to each child.
90% identifiable third cousin
There is a 90% chance that third cousins will share enough DNA for the relationship to be detected but only a 50% chance that you will share enough DNA with a fourth cousin for the relationship to be identified. This is because of the random way that autosomal DNA is inherited, causing third, fourth, and more distant cousins to not necessarily have any detectable half-identical regions.
Between 20,000 and 25,000 genes
The Human Genome Project estimated that humans have between 20,000 and 25,000 genes, however genes do not code for proteins. In humans, genes vary in size from a few hundred DNA bases to more than 2 million bases. Every person has two copies of each gene, one passed down from each parent. Most genes are the same in all people but less than 1% of the populations genes are slightly different. Alleles are forms of the same gene with small differences in their sequence of DNA bases, making up small differences to each person’s unique physical features.
