Each zodiac sign belongs to an element. Fire signs are Aries, Leo, Sagittarius, Water signs are Cancer, Scorpio, Pisces, Air signs are Gemini, Libra, Aquarius and Earth signs are Taurus, Virgo, ...

5 fun facts about evolution. The last common ancestor of all life on Earth is estimated to have existed around 4.2 billion years ago.; There are three ingredients necessary for natural selection ...