How life began

Research on the origins of life on Earth is done by studying the genes of organisms with and without cell nuclei. The research under way at the Evolutionary Biology Centre in Uppsala may also make a major contribution to an understanding of how biodiversity arose.

For a long time, all life on Earth consisted of prokaryotes, i.e. unicellular organisms with no discrete cell nucleus. The appearance of eukaryotes — the first organisms with a cell nucleus — two billion years ago was a step towards the emergence of present-day plants and animals.

Underlying this development was the phenomenon of mutations, changes in the organisms´ genetic make-up. Why did these changes arise and what was the role of mutations in the emergence of new life forms? These are central questions addressed by the two research groups belonging to the strong research environment at the Evolutionary Biology Centre.

Genetic comparison

To understand these evolutionary processes, the researchers are studying DNA sequences in the gene pool by means of data analyses and various molecular methods. To date, the genetic make-up of four bacterium species has been mapped and published. A fifth is almost complete and study of several new bacteria has begun.

‘ The idea is that we should then be able to compare the species genetically and correlate the differences with the species´ habitats,´ relates Professor Siv Andersson, who heads one of the research groups.

In these comparisons, the researchers can also measure the rapidity of various types of mutation. Part of the research is aimed at explaining what underlies disparities in mutation rates.

Using knowledge of how various parts of the gene pool evolve, researchers can then go on to study how natural selection determines which genetic variants persist and which are eliminated.

This is part of one of the great challenges in 21st-century biology: to match genetic variants with the various features and characteristics of organisms, says Professor Hans Ellegren, who heads the second research group.

Young researchers

The funding initiative for strong research environments will strengthen collaboration between the groups and improve research conditions. The money will be used mainly to recruit postdoctoral and young researchers.

‘ We don´t have a special project to run. Instead, the aim is for the initiative to benefit the whole field ,´ says Hans Ellegren.

Story: Peter Tillhammar

Siv Andersson ( www.egs.uu.se/molev/staff/siv.html external link, opens in new window