1. Fossil Record
shows us that:
a) Earlier types of
organisms have
changed or evolved
into later ones.
a) There are many
“missing links” that
have been found to
show a relationship
and development into
a new species.
http://images.google.com/imgres?imgurl=http://www.trilobita.de/gallery/others/archaeopteryx1
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Fossil Record shows us that:
1. Earlier groups have: evolved into later
ones—there are links between groups.
b) Species living today are just a small
number of those that have existed.
a) Most have gone extinct.
c) Many organisms present early in history
were smaller and simpler than modern
organisms.
Fossil Record shows us that:
1. Earlier groups have: evolved into later
ones—there are links between groups.
2. Species existing today are: a small
percentage of those that have ever
existed.
3. Many organisms existing earlier were
smaller and simpler than later organisms.
Plant and animal species are disappearing at least 1000 times faster than any
time within the last 65 million years (since the last mass extinction). And 100
times faster than background species extinctions (low levels of extinction over
time).
By 2100, 25% of all species that lived on Earth in 1900 will be gone!
d)
There have been several
mass extinctions.
a)
b)
c)
d)
5 known mass extinctions
The largest was at the end
of the Permian period 250
million years ago
The most well-known is the
K-T event (between the
Cretaceous-Tertiary
periods) 65 million years
ago. This is the one that
caused the dinosaurs to go
extinct.
Each mass extinction wiped
out 50-95% of the species
existing at the time.
http://dept.kent.edu/geology/ehlab/time_scale/time_scale.gif
Fossil Record shows us that:
4. There have been at least five known
mass extinctions.
1. The Permian extinction was the largest, but
the K-T extinction is the most well-known
because it caused the dinosaurs to go
extinct.
2. Each mass extinction causes 50-95% of the
current species to go extinct.
The fossil record is incomplete, meaning
there are spaces in it. Some species have
just appeared or disappeared.
Why might that be?
• Fossil evidence supports the theory of
punctuated equilibrium.
– What is this theory?
– Does this support Darwin’s theory of
evolution?
Incompleteness due to:
1. Mass extinctions
2. May not have had the conditions needed
to fossilize
3. We may have just not found the missing
links yet
4. Change may have happened quickly, not
really having a missing link
• Incompleteness due to:
1. Mass Extinctions
2. Not the right conditions for fossilization to
occur
3. Have not found all the fossils yet
4. Change happened very quickly
Other evidence besides fossil records:
B. Lab experiments and nature
– We can see examples of evolution
everywhere
– Drug resistance
• What important scientific discovery
changed the way we explain evolution
instead of only relying on fossil evidence?
3. Comparative Genomics
– Scientists can use DNA to compare gene
sequences of species to see how closely
they are related.
4. Artifacts
– Scientists can use artifacts to determine
possible cognitive levels.
2. Lab experiments and Nature
•
Examples: drug resistance, diversity of
species
3. Comparative Genomics
•
Compare DNA of species
4. Artifacts
•
Used to determine cognitive ability