Neutral Plantings

摘要

The transcriptome of an organism encompasses all of its gene transcripts at a specific time and changes with the individual's environment and developmental stage. These changes either could be guided by adaptive selection or, like the neutral theory of gene evolution, may result from random events not under selection. Taking advantage of the genomic database of the plant Arabidopsis, Broadley et al. examined more than 18,000 gene transcripts in leaves of 14 taxa from the cabbage family. They found differences in the expression of a gene among taxa, suggesting that there was plasticity in expression in the most recent com-mon ancestor or that the founder effect of a small population may have resulted in differential changes in gene expression among descendant taxa, but that the changes observed do not reflect functional adaptation.