One more cross-species study reports that most duplicated genes experience a short post-duplication period of relaxed neutral selection [ 12].
These observations suggest, consistent with previous findings, that paralogs do indeed experience a post-duplication period of accelerated evolution, which is apparently due to the relaxation of purifying selection.
As neither we nor others [ 58, 62, 74] have observed evidence of additional nuclear gene duplications or chromosomal duplications in this time period, the PHYA event was likely a tandem or segmental duplication, rather than whole genome duplication.
Some duplicates from this period continued to undergo tandem duplications less than 125 Ma in a number of separate angiosperm lineages until recently.
Based on these results, an analysis of erosion against velocity demonstrates that the redesigned rotor disc proposed here leads to the duplication of the time period used at present between maintenance repairs.
This could be due to a recent gene duplication within a short period of time (not enough time elapsed to allow for the accumulation of nucleotide substitutions).
It is thus conceivable that the human orthologs of these intact genes were functional for a certain time period after duplication before they ultimately became disabled.
Arabidopsis thaliana alone has experienced at least two recent whole genome duplication events in the period between its divergence from Carica papaya (∼72 million years ago) and Arabidopsis lyrata (∼10 million years ago) commonly referred to as α and β duplication events, respectively.
Using relative dating in the phylogenetic analyses, as well as the species distribution of the genes, we can place the duplication events to the period after the divergence of invertebrate chordates and vertebrates, but before the divergence of lobe-finned fishes (including tetrapods) and ray-finned fishes (including teleosts).
Extended periods of relatively low levels of retrotransposition may allow some mobile elements to retain duplication capability for long periods of time.
We do not observe that deletions are neutral more often than duplications during the streamlining period.
