Transcript Evidence for Evolution PowerPoint

Evidence
for
Evolution
Evidence for Evolution
•Homology
•Convergent evolution
•Vestigial structures
•Embryology
•Fossils
•DNA
Homology– Evidence of a
Common Ancestor
Homology– Evidence of a
Common Ancestor
•When we see very similar parts
in many living things, we gain
evidence of their common
ancestor and its characteristics.
Convergent Evolution
Convergent Evolution
Convergent Evolution
Convergent Evolution
Convergent Evolution
•Most evolution is Divergent (species with
similar traits have a common ancestor)
•According to Natural Selection, species
evolve traits that help them survive in an
environment.
•Sometimes, the requirements to survive in
an environment are so strong that several
VERY DIFFERENT SPECIES evolve traits
that function in similar ways. This is
convergent evolution.
Vestigial Structures
Vestigial Structures
Vestigial Structures
Vestigial Structures
Vestigial Structures
Vestigial Structures
•Structures that are no longer
useful, such as our appendix,, or
the fingers on a whale are
vestigial structures. They are
evidence that these creatures
evolved from other creatures that
used these structures.
Embryology
Embryology
Embryology
•Embryos of some animals show
traits that are not present in adults
such as gills and tails in humans.
These are evidence that these traits
were found in our ancestors.
Fossils
Fossils
Fossils
Fossils
Fossils
Fossils
•There are fossils of many creatures
that no longer exist today. They often
show missing links between species
that exist today and their ancestors.
•We also see that fossils deeper in the
earth only show simpler creatures with
more advanced life forms closer to the
surface.
DNA
Similarities
DNA Similarities
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If you look at the DNA of living creatures you can
see the similarities.
Many sections of DNA are don’t code foe
anything at all. These sections are similar to
working or useful sections in other creatures.
Even in human DNA, you can see the broken
parts of code that were important in an organism
long ago