Fossil Evidence for Evolution by yurtgc548


									Fossil Evidence for Evolution
          What is a fossil?
   A fossil is a physical
    remain of an ancient
   The study of fossils is
    called paleontology.

                              Fossils of a fish
                              and a wasp.
    How are fossils made?
   The organism dies and is          Many times there are too
    covered by mud, dirt or            many bacteria and the
    rock.                              organism decays before
   The body starts to decay,          fossilization can occur.
    caused by bacteria                Because of this, the fossil
    metabolizing the organic           record is far from complete.
   If few bacteria are present,
    mineral replacement occurs
    and eventually the
    organism becomes rock.
       Soft Tissue Fossils
   Soft tissue can sometimes
    make a fossil record if it
    leaves an impression in
    mud that hardens and is
   Soft tissue fossils can also
    happen in ice or amber,
    where the actual organism
    was preserved
   For example, insects in
    amber or wooly mammoth
    in Arctic ice
                         Extinction is when the last
                          living member of a species
                          dies out
                         Extinctions have been
                          happening at a much faster
                         This is due to the increase
                          in human population-
                          hunters, decrease of habitat
                          ie; passenger pigeon

A passenger pigeon.
How do fossils provide
evidence for Evolution?
   Fossils provide physical        Fossils also are evidence of
    records of organisms that        the rate of evolutionary
    are not alive today.             change.
   These are very helpful for      Fossils in intermediate
    scientists to study body         stages between species
    structures of ancient            and their ancestors give
    organisms and relate them        clear evidence of evolution.
    to modern species.

                                     Fossils of feathered dinosaurs
                                     found in China reveal some
                                     evolutionary stages between
                                     dinosaurs and birds.

To top