The Human Genome Project (HGP) was one of the great feats of exploration in history – an inward voyage of discovery rather than an outward exploration of the planet or the cosmos; an international research effort to sequence and map all of the genes – together known as the genome – of members of our species, Homo sapiens. Completed in April 2003, the HGP gave us the ability, for the first time, to read nature’s complete genetic blueprint for building a human being.
…it is possible that the first DNA came to the world from outside and then evolved. Whether you want to bring up religious arguments, I think that’s fine, too. They can all in a way fit into the same arguments. You could say the first DNA was seeded by God. Or you can say it came from an extraterrestrial source? Who knows?
When we started sequencing the genome, the prediction was that there would be 100,000 human genes. That prediction was based largely on the few genes that had been sequenced. Their size was around 30,000 base pairs.
Since the human genome was 3 billion base pairs, just doing the math, it seemed that if the average gene was 30,000 base pairs, then there would be 100,000 genes (in a human). I think that is sort of a simplistic view of where that 100,000 number came from.
Of the things that had been sequenced at the time, a worm was being sequenced and it looked like 20,000 genes in it. So, it seemed reasonable – maybe it was part of our arrogance – that we thought there should be 100,000 human genes.
But in the end, when we sequenced the human genome, it turned out to be – and it’s still a debatable point actually how many genes there are (in humans) – but there are maybe something like 22,000 human genes.
The difference is not the number of genes, but the complexity of the genes that has more to do with the complexity of the organism.
In human genes, one gene tends to make multiple proteins, whereas a lot of things like the worm it’s one gene makes one protein. Our human genes make at least two proteins on average. Some genes make many, many proteins. It’s called ‘differential splicing’ and it’s a way of mixing and matching parts within that gene to make a different protein for a different function. So human genes get more complexity out of the genes that we have than something like a worm.
Long stretches of DNA previously dismissed as “junk” are in fact crucial to the way our genome works, an international team of researchers said…
It is the most significant shift in scientists’ understanding of the way our DNA operates since the sequencing of the human genome in 2000, when it was discovered that our bodies are built and controlled by far fewer genes than expected. Now the next generation of geneticists have updated that picture.
The results of the international Encode project will have a huge impact for geneticists trying to work out how genes operate. The findings will also provide new leads for scientists looking for treatments for conditions such as heart disease, diabetes and Crohn’s disease that have their roots partly in glitches in the DNA. Until now, the focus had largely been on looking for errors within genes themselves, but the Encode research will help guide the hunt for problem areas that lie elsewhere in our DNA sequence.