"[These webpages] give a clear explanation on how the polymerase chain reaction works and why it is useful."
Understanding the human genome can be seen as the key to understanding the mystery of human life itself. the Human Genome Project set out to identify (map) all of the genes in the human chromosomes (around 30 000 of them) and to sequence the 3 billion base pairs which make up the human DNA. The project was set up in 1990, and involved scientists working in 18 different countries. This international involvement is very important – knowledge of the human genome should belong to everyone.
Who provided the DNA that was analysed? No-one really knows, although it is known that a group of volunteers gave samples, some of which were then chosen anonymously and at random for all the scientists to work with.
The project also had specific aims about the storage and analysis of all the data involved, and consideration of the ethical, legal and social issues which are inevitably raised when such personal genetic information is unravelled was also part of the brief. The project has cost around 2.7 billion US dollars, and has shown that every individual has at least 99.9% of their DNA in common.
When the Human Genome Project was first launched, scientists worked on mapping the individual genes, and then as technology developed they moved on to sequencing the DNA in detail. It was thought it would take 15 years to complete the project, but technology moved on so fast that the genome was sequenced in 2003, two years ahead of schedule. Two automated processes which were developed had a major impact on the success of the project. These were the polymerase chain reaction and DNA sequencing.
The 1000 Genome project is now in progress. In a similar international effort to the original Human Genome Project, scientists are analysing whole genomes and gene regions from many different samples (actually around 2500 people are contributing). They hope to produce a catalogue of human genetic variants and identify the regions of the genome most commonly associated with different types of disease.