[Taxacom] Surprise from a whole-genome study

[Les Watson]

"Surprises" of this kind, postulating promiscuous exchange of genetic 
information, seem to have proliferated in recent times and have even had 
lurid publicity. For example, New Scientist no. 2692 (24th January 2009) 
trumpeted on the cover that "Darwin was wrong", and carried an article 
quoting respectable biologists and papers from serious journals (PNAS, 
Genome Biology, J. Theoretical Biology, etc.).

I cannot comment on latter-day evidence from nucleic acid sequencing, 
which needs critical scrutiny. However, the peculiar patterns in 
character state distributions which have long bedeviled attempts at 
arriving at phylogenetic details (as distinct from major trends) long 
ago caused me in desperation to suspect the occasional occurrence of 
high level lateral exchange of genetic information in higher plants, 
presumably involving viral, bacterial or fungal pathogens; and this is 
of course easier to envisage in vegetatively reproducing organisms. In a 
1985 paper, I commented on the possibility of "clandestine transfer of 
genetic information, involving natural occurrence of events it is now 
becoming commonplace to procure by genetic engineering ..."; this in 
connection with the bizarre distribution of C4 photosynthesis, which 
offers opportunities re both nuclear and plastid genomes.

In any case, taxonomists re-organizing classifications on the evidence 
of  'phylogenies' representing tiny samples of genomes are skating on 
very thin ice.

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Les Watson
10 Maitland Avenue, Little Grove, Albany WA 6330, Australia
Email (1): leswatson at westnet.com.au
Email (2): http://delta-intkey.com/contact/watson.htm
Phone: +61 (8) 98 44 4398


On 26/10/2010 9:43 AM, Bob Mesibov wrote:
> See
>
> Moran NA,&  Jarvik T (2010). Lateral transfer of genes from fungi underlies carotenoid production in aphids. Science (New York, N.Y.), 328 (5978), 624-7 PMID: 20431015
>
> (featured in the excellent ASM blog 'Small Things Considered')
>
> Nearly as exciting as the finding that photosynthesis in at least one nudibranch is operated by genes in the algal symbionts *and* the host nudibranch, thanks to HGT.

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