Ferns have it made in the shade

Here's a great bit of research just reported by my colleague Emily over at the No seeds, no fruits, no flowers: no problem blog.  Everyone knows that ferns grow well in the deep forest shade, but this is no easy trick because that leaf canopy overhead captures most of the sunlight, especially at the blue end of the spectrum. Ferns have a neochrome pigment that allows them to use both red and blue light more efficiently.  This isn't news in and of itself, but the real news is that the gene for this pigment comes from a hornwort (image by Jason Hollinger, Wikimedia Creative Commons), a little bryophyte that may represent the basal lineage of living land

plants. Ferns are not a direct ancestor of hornworts, and the two lineages would have diverged over 400 million years ago, and the molecular clock would put the date at which ferns acquired these genes at less than 200 million years ago.  How did they do that?  The unsatisfying answer is that we don't know. This transfer of whole genes seems to happen way more commonly than biologists thought and the hypothesized mechanism is called horizontal gene transfer, basically nature's own GMOs.  But no one knows how it happens!  Maybe a virus does it?  This genetic event really allowed ferns to adapt to the understory of gymnosperms and then angiosperms, so it's a big event in fern evolutionary history.  Here's a nice news account of this research from the Economist (link also provided by Emily)((TPP only gets the Economist to read after his wife is done with it at her office, so he's behind.)).  Go ahead compare this science article to whatever news periodical you read.