Genomics

For many years, genomics has been focused on microorganisms, which have relatively small genomes. However, more recently the field has been energized by the advent of more industrialized, higher-throughput sequencing technologies. By 2001 more than seventy organisms had been completely sequenced, and a working draft of the human genome had been produced. Vigorous efforts have now been initiated to map the mouse genome, and one company already claims to have completed the sequence. From the description of the structure of the genetic material by James Watson and Francis Crick in 1953, it will have taken only about fifty years to determine the complete genetic codes of humans and most of the model organisms that are important in biological research.

Size comparison of selected completed genomes. Most of these organisms are of economic, medical, or scientific importance.

Of what value is the knowledge of these genomes? How are they being used within the scientific community? The first fully sequenced genomes included the fruit fly, a worm, and a number of bacteria and yeast. One of the first analyses performed was to simply compare the sequences between organisms, in order to identify what is shared in common and what is different. This allows the very specific comparison of organisms that will enable the refining of phylogenic relationships. This kind of information is also very valuable for asking questions about how organisms have evolved, how they adapt to different circumstances, and what gene products contribute to their survival in various environmental conditions.