Download Evolution Evidence_ Summary Day_2013

Evolution Evidence:
1.
2.
3.
4.
5.
Adaptations (Natural Selection)
Comparative Biochemistry (DNA)
Comparative Anatomy
Comparative Embryology
Fossils
Remember Darwin?
The idea of Natural Selection leads to
“Descent with Modification”
Drawing Box Notes
Title “Evidence of Evolution”
1.
2.
4.
5.
3.
Summary
1. Adaptations: features
suited to a particular environment
that allow organisms to survive
Inuit people, who
live in the extreme
cold of the Arctic,
have short, stout
bodies that
conserve heat.
Masai people,
who live in
the arid lands
of eastern
Africa, have
tall, lean
bodies that
disperse heat
well.
Bird Beak Adaptations:
Evidence #1 - Adaptations
1. Draw ONE organism and identify an
adaptation for it.
2. List the 4 tenants of Natural Selection
2. Comparative Biochemistry
• Similar DNA
sequences=
• Similar Gene
segments of the
DNA
• Code for similar
traits
• In closely related
species
3. Comparative Anatomy:
Structural similarities link related species
Homologous Structures:
Two species, in which share a common ancestor.
– At some point, there was isolation within the species and
different evolutionary paths were taken
Divergence can lead to
HOMOLOGOUS structures
Common
ancestor
Two new
species
Analogous Structures:
• Two species, in which DO NOT share a recent
common ancestor.
– Due to similar environmental pressures, two unrelated
species can develop the same trait
Convergent Evolution can lead to
analogous structures
NO recent common ancestor
Develop similar traits
Comparative Anatomy
Analogous:
1. Different
ancestors
2. “analogy”=like
3. Different
underlying
structures
4. Same Function
5. Similar
Environments
Homologous:
1. Same ancestor
2. “homo”=same
3. Same
underlying
structures
4. Different
Functions
5. Different
Environments
Vestigial Structures:
• Traits that are no longer used, but still
evident in the genetic code.
• Proof that recent common ancestors
had the trait!
The top 10
Vestigial
Structures
The Wings on Flightless Birds
• The Cassowary, the sexier, but less-wellknown flightless bird. Kiwi bird in Australia.
Hind Leg Bones in Whales
• Whale skeleton showing pelvis and thigh
bones. Snake hind limbs.
Erector Pili and Body Hair
• When a rabbit is scared, its hair stands on
end. When a human is scared, he or she
calls the police.
The Human Tailbone (Coccyx)
• The human tailbone doesn't do much, but
really hurts if you land on it.
The Blind Fish Astyanax Mexicanus
and Blind Mole rat
• Have eyes  Can’t see 
Wisdom Teeth in Humans
• They need regular brushing but did they
come from Apes?
The Sexual Organs of Dandelions
• Send in the clones ...
Fake reproduction in Virgin Whiptail
Lizards (Vestigial Behavior)
• Feminist lizards take the male out of the
picture.
Male Breast Tissue and Nipples
• They are not fully functional and, because
cancer can grow in male or female breast
tissue, the tissue can be dangerous.
The Human Appendix
• In 2000, in fact, there were nearly 300,000
appendectomies performed in the United
States, and 371 deaths from appendicitis.
Evidence #3 – Comparative Anatomy
Explain how each of the following is
evidence for evolution and provide
ONE example of each:
1. Homologous Structures2. Analogous Structures3. Vestigial Structures-
Embryological Development
Similar embryo development in closely related
species
Evidence #4 – Embryonic Development
Anatomy
1. Explain what scientists conclude
from comparing the embryos of
organisms to others.
2. Do you think this is a valid piece of
evidence? Why or Why Not?
5. Fossil Evidence
• Once living remains
of organisms
• Limited
1.Type of material
preserved (bone,
shell, impressions,
amber)
2.Incomplete record
3.Easily disrupted
Plant Fossil Evidence
Law of Superposition
• Sedimentary layers are deposited in a
time sequence
• Oldest rock on the bottom, youngest at the
top
Youngest
Oldest
Dating Fossils
• Relative Age
– describes
approximate
age of fossil
relative to
location.
– Ex. “This fossil
is located
beneath that
fossil, so it is
relatively older.”
– Law of
superposition
• Absolute age
– Age of a fossil in
years
– Can be calculated
using radioactive
dating
– Ex. “This fossil is
approximately 1
million years old.”
Evidence #5 - Fossils
1. Draw an image that demonstrates
the “Law of Superposition”
Rules:
- Represent 4 layers
- Draw ONE organism in each layer
to represent the relative age of the
fossils.
Box #6 - Summary
What conclusions can scientists make based
on all of this previous (#1-5) evidence?
Summarize this in one BOLD statement 