October 13, 2016 at 02:24AM

Today I Learned: 1) When ISIS first invaded and took ground in Iraq, they did so largely on the back of a massively successful media campaign. ISIS only had a few thousand troops, but they put out a number of well-produced battlefield videos on Twitter and Facebook and other platforms that made them look like a much bigger threat, essentially magnifying the effects of a string of small victories. As a result, they were able to force the surrender of Iraqi forces an order of magnitude larger than their own. 2) There is a transposable element*, called the P-element, that was acquired by the fruit fly D. melanogaster very recently (within the last couple hundred years). It confers a whole constellation of nasty phenotypes on its bearer, including a high probability of sterility. When discovered, the P-element quickly became a classic example of the spread of a selfish element in a naïve population. Also, since the invasion, D. melanogaster has developed an RNA interference pathway to shut it down. More recently (between 1800 and 1950!), the P-element invaded another fly species, D. simulans (which I assume is named so because it's similar to D. melanogaster?). Evidence points to a single horizontal gene transfer event being behind the invasion. * a transposable element is a gene which does nothing but move and/or copy itself into other parts of the genome, found almost exclusively in Eukaryotes. It's hotly contested whether or not transposable elements are functional in some way, if they're just selfish genes that their hosts can't get rid of. 3) Viridis, the current most-popular colormap in matplotlib, is very similar to Matlab's current default colormap, parula, but has been tweaked so that a) the gradient is visually smooth across the entire range of the colormap and b) it doesn't lose contrast if you're red-green colorblind. For more details, see http://ift.tt/2dZgvvp.