A concise blog reporting on articles of importance to the future of human and social development.

Wednesday, March 26, 2008

Science can read you like a (progressively less expensive) book

Venessa Posavec at MemeBox FutureBlogger uploaded this deceptively short post today.

Her post describes the very rapid decrease in the cost (in both time and money) of having a human gemone sequenced. While she focuses on the utility and function of these mounds of data, I'd like to give a different perspective, the role of technology.

Gene sequencing, of the kind done by the Human Genome Project, is a hugely complicated process. It might sound simple, there are only four letters in the language of our DNA, but actually getting down and reading out the book of life for the first time took millions of dollars worth of man-hours and laboratory equipment. After all, you cant just grab your microscope and get somebody to take notes while you read off the code. The individual base pairs of DNA are only a couple of nanometers wide, too small for even the most powerful vision enhancement. Even if you could read the DNA directly, there are some 3 billion base pairs in the human genome and there is no room for error.

So how did they solve this problem? By inventing the new techniques and machines to assist in reading out and piecing together the code. The Human Genome project used what they call the 'shotgun' approach. They take a strand of DNA, make a few billion copies (which is easy, because DNA is designed to do that), then break these copies up into short chunks. These chunks are small enough for specialized machinery to read off the letters a few hundred at a time. Once the DNA is broken up into random pieces and fed into a computer, it then takes a relatively simple, but highly time-consuming process to piece matching portions together into a complete strand.

As with most other sciences, the rapid improvement of informational technology boosts the second two steps of the process exponentially. The jigsaw-like matching algorithms have been improved over time, the computers that run them have gotten faster, and the system for reading off the individual chunks has been improved as well. Yet at the same time, these systems become more inexpensive and require less expertise to operate.

Technological advancement like this is the root of nearly all the recent leaps forward in science that have yet to make themselves felt. The first human genome was sequenced in 2003, but we still haven't finished translating the finished code into usable knowledge.

No comments: