Transcript Fossil Record - AaronFreeman

Macroevolution
What is Macroevolution?
Evolution happening on a large scale;
results in the formation of new taxonomic
groups.
Evidence: Fossil Record
The picture may be smudged in places
Serve
as snapshots
of the past
can
and may
have bits missing,
butthat
fossils
should
show that
life evolutionary
is old and haschange.
changed over
time.
Fossil records can have missing pieces and be
dated inaccurately; not always best evidence
Evidence: Comparative
Morphology
Studying shapes and structures of organisms.
Homologous Structures
Structure present in organisms that have
visible similarities, but different functions
Divergent Evolution
Organisms are
thought to have
the same
ancestor, but
separated
(diverged) over
time
Analogous Structures
Structure of an organism that is similar in
function, but different in structure.
Convergent Evolution
Organisms are
thought to have
different ancestors,
but have developed
similarities
(converged) over
time due to
environmental
pressures
Vestigial Structures
Structures that
have no real
function;
thought to have
been used at
one point in
time
Evidence: Embryology
Study of
embryos and
their
development
What does this mean?
Later in
Similarities in
development
DNA
Embryos
have
2
development
starts expressing
similarities:
show a potential
specific
common
characteristics
for
1. Gillancestor
Slits
2.each
Tail organism
Evidence: Biochemistry
• Compare the
monomers of
DNA, RNA, and
sequences of
proteins between
different
organisms.
• Found similarities
between
organisms
Study of amino acid sequences within
hemoglobin in several organisms
when compared to humans.
Organism
Different
Amino Acids
67
What does this
mean?
Chicken
65
A possible
common
ancestor
Mouse
27
Gorilla
1
Frog