Download #5 -Evidence for Evolution Notes

-Evidence for
Evolution NotesI. Fossil Record
A. The fossil
record is all
fossils that have
been collected
over time
B. Organisms
have changed
over time
according to
fossil record
1. Evolution is
gradual change in
organisms over
time.
II. Comparative
Anatomy
A. Basic body
plans can be
compared
1. Fish,
amphibians,
reptiles,
birds, and
mammalssimilar
internal
skeleton and
backbone“Vertebrates”
2.
Presumably,
All 5 groups
inherited
these
similarities
from an early
common,
ancestor
B. Homologous
Structuresstructures that
related species
have inherited
from a common
ancestor
1. dolphin
flipper, dog’s
leg, bird’s
wing- all bones
are arranged
in a similar
way
C. Vestigial
Structuresreduced forms of
functional
structures
inherited from a
common ancestor.
1.
Evolutionary
theory
predicts that
features of
ancestors
that no longer
have a
function for
that species
over time will
become
smaller until
they are lost.
(ex. Snake
pelvis, human
appendix, kiwi wings)
D. Analogous
Structures –
structures
that can be
used for the
same function
and can be
superficially
similar, but not
inherited
from a
common
ancestor. (ex.
Wing of an
eagle, and wing
of a beetle)
III. Similarities in
Early Development
A. Organisms
have similarities
in embryonic
development
1. Chickens,
turtles, rats
all have tails
and gill slits-
suggests that
vertebrates
share a
common
ancestor.
IV. Similarities in
Biochemistry
A. DNA is
hereditary
materialorganisms closely
related would
have similar DNA
1. DNA
analysis shows
common
ancestory
a. ex.
elephant
shrew
more
similarities
in DNA to
elephants,
not
rodents
B. DNA shows
more reliable
evidence of
common
ancestory than
similarities in
body structure or
early
development
V.
Geographic
Distributiondistribution of
plants and
animals around
world.
Organisms in a
particular area
are more likely
to share a
common
ancestor.
(ex. Mara- same
niche as English
rabbit, but more
closely related to S.
Amer. Animals than
rabbit because they
shared a common
ancestor)
VI. Adaptationtrait shaped by
natural selection
that increases an
organism’s
reproductive success.
(ex. Finches of
Galapagos adapted to
individual islands,
creating variation of
beaks, antimicrobial
resistance of
bacteria to
antibiotics)
VII. Combining the
EvidenceA. Scientists
combine all types
of evidence for
evolution to
determine
relationshipsfossil, similarities
in body structure
and early
development, and
DNA!!
B. Phylogenetic
tree- diagram
that shows how
scientists think
different groups
of organisms are
related based on
evidence.