Mystery of the Human DNA

The Human Genome Project

Vinutha Simha
Sep 4, 2018 · 4 min read

We have all come across things like heredity and genetics. These aspects have a role to play in physical, intellectual and behavioural attributes. What evidently seems like a specific trait of an individual may be a series of distinctive elements passed down over hundreds of years or through generations. Although heredity has baffled the human mind for eons, the scientific community has been trying to resolve this mystery. In order to give this tenet a structured study with a scientific approach, scientists started the ‘Human Genome Project’ (HGP) in 1990.

Human Genome Project was an international scientific research project with scientists from over 20 different countries coming together. It all started when in 1986, a group of US scientists wanted to sequence the entire human genome in order to understand the causes of cancer and the long term damaging effects of radiation on human DNA. The first draft of HGP was published in the year 2000 and the project was completed with the full sequence of human genome in February 2003.

What is Human Genome?

Before we delve into the findings of HGP, let us understand what a genome is. One of the most basic building blocks of our body is the DNA (Deoxyribonucleic acid). It is a molecule with two chains coiling around each other in a double helix formation. A human DNA contains two copies of 23 chromosomes each, carrying genetic information regarding growth, development and functioning throughout the living cycle. Each chromosome defines specific characteristics and determines the way we look, our health and the way our body works. Some of the DNA have chromosomes carrying genetic information about traits which are inherited, called genes. While DNA at large determines how the cells are going to live and function, genes are only a subset of DNA that defines inherited traits. All the genes together are known as ‘genome’.

DNA is made up of four chemical bases –A, C, G and T bases. All these bases are arranged in different ways, different order and different lengths, called the ‘DNA Sequence’. A human genome sequence consists of about 3.2billion base pairs, which is but a combination of the four bases in different orders. An average size gene has about 3000 of these bases. The biggest known human gene, dystrophin, is made up of about 2.4 million bases.

What was Human Genome Project?

HGP has given the world a resource of detailed information about the structure, organization and function of the complete set of human genes. HGP researchers deciphered the human genome in three ways- determining the genes sequence, making maps to show the locations of genes and producing linkage maps through which inherited traits can be tracked over generations. The HGP also gave detailed information about chromosomes. All the current research into genetics and treating diseases stems from the information produced by the Human Genome Project. Biomedical technology and research are particular beneficiaries of the HGP.

Before the completion of the Human Genome Project, many scientists were expecting to find 100,000 or more genes in our genome. This was based on the assumption that humans were complex creatures. However, it turned out we only have around 24,000 genes. This is a few more than a chimpanzee. Even more surprisingly, scientists discovered that a large part of our genome is made up of DNA that doesn’t code for genes. However, scientists have now discovered that much of this non-coding DNA plays an important role in controlling the activity of our genes. It codes for genetic switches that regulate when and where genes are switched on and off in your body.

Some interesting findings from Human Genome Project

  • 98% of the DNA in human genes is exactly the same as a chimpanzee’s
  • 99.9% of human DNA is identical to that of everyone else in the world.
  • Only a 0.1% of the human DNA is unique to each person and determines the way we look different from each other.
  • A variant of a single gene determines skin colour, hair colour and eye colour.
  • Excluding identical twins, it’s a one-in-a-billion chance that matching DNA profiles are from different people.
  • Humans are different from fruit flies or worms because we have more ‘control genes’.
  • Hundreds of human genes appear to have come from bacteria
  • Most genetic mutations occur in males.
  • Genetically modified sheep produce a human protein in their milk.

Information is only as good as the ability to use it. Therefore, advanced methods for widely disseminating the information generated by the HGP to scientists, physicians and others is necessary in order to ensure the most rapid application of research results for the benefit of humanity.

Veeksha-The JU Higher Education Chronicle

Become a part of a community that believes in the power of ideas with Veeksha, an online publication on latest higher education trends and research by the Jain University (JU) Press. Keep yourself abreast with topical issues with our incisive and analytical articles.

Vinutha Simha

Written by

Veeksha-The JU Higher Education Chronicle

Become a part of a community that believes in the power of ideas with Veeksha, an online publication on latest higher education trends and research by the Jain University (JU) Press. Keep yourself abreast with topical issues with our incisive and analytical articles.

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