Smoking cannabis can reduce a man’s fertility by altering the size and shape of his sperm, research has shown. Photograph:  Gareth Fuller/PA

Men who smoke cannabis may be damaging their sperm and should give up the habit if they are trying to start a family, according to new research. It (...)

Photo issued by the University of Sheffield of an organism found after a team from the university sent a a balloon high into the stratosphere, which could ‘completely change our view of biology and evolution’. Photograph: University of Sheffield/PA Wire

Scientists believe they have found the first evidence of life arriving to Earth from space, which could “completely change our view of biology and evo(...)