A recent study that compared convergent evolution of photosynthetic pathways with parallel evolution concluded that duplications are not essential for the development of C photosynthesis are not well established.
Knowledge of the rate of point mutation is of fundamental importance, because mutations are a vital source of genetic novelty and a significant cause of human diseases.
We find that mutation rate is approximately constant per year and largely similar among genes.
Similarity of mutation rates among lineages with vastly different generation lengths and physiological attributes points to a much greater contribution of replication-independent mutational processes to the overall mutation rate.
Our results suggest that the average mammalian genome mutation rate is 2.2 × 10 Rates of point mutation can be determined indirectly by estimating the rate at which the neutral substitutions accumulate in protein-coding genes (1).
Synonymous substitutions in protein-coding genes generally are free from natural selection and are used frequently for inferring neutral substitution rates (1, 2).
In particular, the fourfold-degenerate sites are expected to harbor only the neutral substitutions, because all mutations at these sites are synonymous at the amino acid sequence level.
By using estimates of evolutionary distances based on neutral substitutions, many studies have examined the null hypotheses of uniformity of neutral mutation rates among genes within a genome and among mammalian lineages and have come to conflicting conclusions (2–9).
For example, significant differences in mutation rates among mammalian lineages reported over the last two decades led to the proposal of the generation-time effect hypothesis (10–13).
However, Easteal (14) have argued that previous results of substantial differences among lineages observed may have been caused by the use of incorrect fossil dates or inappropriate outgroups.
photosynthesis requires substantial changes to genes and gene functions effecting phenotypic, physiological and enzymatic changes.
We investigate the role of ancient whole genome duplications (WGD) as a source of new genes in the development of this trait and compare expression between paralog copies. We establish through comparison of paralog synonymous substitution rate that both species share this paleohexaploidy.
Homologous clusters of photosynthetic gene families show that gene copy numbers are similar to what would be expected given their duplication history and that no significant difference between the C, where orthologs have extremely similar expression patterns in different organs, seedlings and seeds.