passage: Many plants and animal species have lived on Earth .
  Most are no longer alive .
  Only a tiny number of species still live on Earth .
  If not for fossils , we would know little about species that did not survive .
  Fossils provide evidence .
  They give us clues to past life on Earth .
  They tell us that life on Earth has changed over time .
  Fossils in younger rock Fossils can also tell us about how plants and animals lived in the past .
  Was it land or marine ?
  Was the water shallow or deep ?
  Fossils can even provide clues to ancient climates .
  They can tell us if it was warm or cold .
  Maybe it was cold or hot ?
  Some places that are now cold were once warm .
  Some places that are now hot and dry were once wet and cool .
  Fossils provide a window into the past .
query_and_answer: What tells us that life on Earth has changed over time ? || Species that still live on Earth
evidences: Fossils provide evidence . They tell us that life on Earth has changed over time .