Download Lecture 3:Fossil Record and Patterns of Evolution

Warm Up 3/22/2017:
1. What are the four principles of Evolution?
2. What are the four pieces of evidence Darwin
used to support his idea?
3. What does it mean for an organism to be
“fit”? Provide one or more real-life examples.
Instructions: Write down 2
observations in your warm ups.
How do you find fossils?
Agenda
1. The Great Fossil Find Activity
2. The Great Fossil Find Poster Design
The Great Fossil Find:
Instructions:
1. Quad up the room
2. Send one member to take an envelope from
the back lab bench.
Lecture 3:Fossil Record and
Patterns of Evolution
The Fossil Record
1. Provides evidence about the history of life on
Earth (but it is incomplete)
a) 99% of all species on Earth extinct
2. Shows how organisms have changed over
time
Fossil Formation
Water carries
small rock
particles to lakes
and seas.
Dead organisms
are buried by
layers of
sediment, which
forms new rock.
The preserved
remains may be
later
discovered and
studied.
Interpreting Fossil Evidence
The age of fossils are determined by using
a) Relative dating
b) Radioactive dating
Interpreting Fossil Evidence
1. Relative Dating: Age is determined by
comparing its placement with that of fossils in
other layers of rock.
Interpreting Fossil Evidence
2. Radioactive Dating: the absolute age of a
fossil is calculated based on the amount of
remaining radioactive isotopes it contains.
Interpreting Fossil Evidence:
Half-life: The time it takes for half of the
radioactive isotope to decay.
Patterns of Evolution
1. Mass Extinctions:
a. Provide ecological opportunities for organisms
that survived
b. Results in bursts of evolution that produced
many new species.
Patterns of Evolution
2. Adaptive Radiation: process by which a single
species or a small group of species evolves into
several different forms that live in different
ways.
Patterns of Evolution
3. Convergent Evolution: the process by which
unrelated organisms come to resemble one
another.
Patterns of Evolution
4. Analogous Structures: Structures that look
and function similarly but are made up of parts
that do not share a common evolutionary
history.
Patterns of Evolution
5. Coevolution: The process by which two
species evolve in response to changes in each
other over time.
Patterns of Evolution
6. Punctuated
equilibrium: periods are
interrupted by brief
periods of more rapid
change.
Gradualism: Slow and
steady change over time.