This indeed happens in europe and america : the fertility rate of new immigrants is higher than average , though it reverts to the local mean within a few years .
Researchers have developed a material that almost instantaneously changes from clear to dark blue when exposed to ultraviolet ( uv ) light , and it just as quickly reverts to clear when the light is turned off .
While it 's hard to imagine britain going hungry , we are certain to see food prices rise , and we may find that the cheap meat we 've come to expect for so long reverts to being the sort of luxury it used to be .