This difference can be seen in Figure 4 and is consistent with the hypothesis that these traits comprise a cultural component that was borrowed by some or all of these groups from a non-ancestral source.
Changes to the ancestral AluY base are greatly overrepresented relative to the alternative two bases at each position, except in the case of 151C, which shows the ancestral G in 8 cases, and a non-ancestral T in 15 cases.
In additional to these 281, a further 11 elements exhibited 5 of the diagnostic mutations, with a non-ancestral change at the final position, which can be assumed to have been generated by a forward mutation event in each of these 11 elements at the diagnostic position.
This possibility then leads to the question how often innovation, defined as gain of stress responsiveness from a non-responsive ancestral gene, occurred in green algae.
The independent evolution of the two bioluminescent enzymes from a non-bioluminescent ancestral acyl-CoA synthetase enzyme is most likely, because it has been well established that the beetle luciferases evolved from non-bioluminescent acyl-CoA synthetases [ 40– 40].
Both are likely derived from a non-African ancestral clade at a similar time depth and both are largely confined to North and East Africa and the Middle East in their present-day geographic distribution.
Sequence randomization between non-ORFan genes indicates that on average less than 1 ORF >300 bp in size can be obtained by chance in a chlorovirus genome; 185 non-ancestral protein families were encoded by ORFs that have a median length >300 bp.
This suggests that at least a fraction of the non-ancestral genes, including the genes with no recognizable homologs in the database, have been captured by HGT from genomes with distinct nucleotide compositional biases and that this event was sufficiently recent so that the difference in nucleotide composition is still visible.
This implies that there is a stronger positive selection upon the SNPs where G. hirsutum has an allele which is non-ancestral.
However, if this were the case, the other non-ancestral nucleotides (A and G) would also be expected to be seen at high frequency, and this is not the case.
Toad blithely sees his non-ancestral home as a desirable commercial property.
