Many plants are genetically programmed to flower at a certain time in the year. In thale cress this occurs early in the spring while the harebell waits much longer. However, much of what we know today about genes that influence the time of flowering in plants concerns the favourite plant of plant geneticists, thale cress (Arapidopsis thaliana). In his doctoral thesis, Harald Hedman has attempted to trace the evolutionary origin of some of the "flowering genes" of thale cress. He has among others investigates a moss in which he found related, light sensitive genes that govern other processes of significance for the reproduction of the moss.
The basis for these studies is gene duplication. Evolution through duplication has been discussed ever since the 1930s, but the idea has assumed prominence during the last century owing to technical advances which have made it possible for gene sequences in entire genomes to be determined.
Discussed ever since the 1930s, but the idea has assumed prominence during the latter part of the last century owing to technical advances which have made it possible for gene sequences in entire genomes to be determined.