Transcript Evolution for MDCPS PD Final

Rationale: As middle school
teachers, we teach a wide
variety of subjects, it is
difficult to be an expert in all
of them.
 Understanding evolution
leads to a rich, aweinspiring perspective of
biology. It enhances our
teaching by unifying all
components of our life
science curriculum.
Diversity and Evolution of
Living Organisms I. The scientific theory of evolution is the
organizing principle of life science.
II. The scientific theory of evolution is
supported by multiple forms of evidence.
III. Natural Selection is a primary mechanism
leading to change over time in organisms.
Evolution is the unifying
theme, the binding force
of all life sciences.
"Nothing in Biology Makes Sense
Except in the Light of Evolution"
Theodosius Dobzhansky
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Evolution is the process
by which modern
organisms have
descended from ancient
ancestors.
Evolution is responsible
for both the remarkable
similarities we see across
all life and the amazing
diversity of that life.
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Medicine: Both the organisms that cause disease
and their hosts evolve.
Agriculture: Genetically similar crops are
vulnerable to disease and pests. Pests can evolve
resistance to modern pesticides.
Taxonomy: Understanding inbreeding and low
genetic variation in endangered species can inform
our decisions for future protection.
Biotechnology: Evolution aids researchers develop
biofuels and other powerful molecular tools.
1.
2.
3.
4.
5.
6.
7.
Fossils
Biogeography
The Law of Superposition
Artificial Selection
Similarities: Comparative Anatomy
Vestigial Organs: The evolutionary legacy
we carry within our own bodies
Overwhelming Genetic Evidence (not
available in Darwin’s time)
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Mold: an imprint in rock
Cast: a mold filled in with hard
minerals, a rocklike model of
the organism
Amber: fossilized tree sap that
can contain organisms
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The study of the geographical distribution of
fossils.
New organisms arise in areas where similar
forms already existed
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Successive layers of rock or soil were
deposited on top of one another by
wind or water
The lowest layer (stratum) will be the
oldest.
Relative age: a given fossil is younger
or older than what is above or below
it
Absolute age: actual age based on
amount of sediment around fossil
The fossil record shows five mass
extinctions in Earth history
The Law of Superposition
The oldest
rock (lowest)
contains the
most
primitive
organisms.
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J.B.S. Haldane answered, “Find me a rabbit
fossil in Pre-Cambrian Rock”
4. Artificial Selection
Darwin noticed how farmers and
breeders allowed only the plants
and animals with desirable
characteristics to reproduce,
causing the evolution of farm
stock. He used this as evidence in
Origin of Species.
These pics both show the same animal,
feral vs. domestic pigs.
Cows being milked in
ancient Egypt
Comparative Anatomy:
The study of
Homologous traits (ex.
forearms) features in
different species that are
similar because those
species share a common
ancestor.
Homologous structures:
A word on structures that look alike, be careful..
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Convergent evolution like sharks and
dolphins. They look alike because they both
live in the same environment.
The fins of sharks and dolphins are
analogous structures, they did not evolve
from common ancestors.
Comparative Embryology:
6. Vestigial structures are features that were
adaptations for an organism’s ancestor but
have evolved to be non-functional due
to a change in the organism’s environment
Anal spurs
on a ball
python
Goose bumps
C= hind legs on whale skeleton
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The fascinating case of the Recurrent
Laryngeal Nerve
7. The latest overwhelming evidence for
evolution comes from molecular biology
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Molecular Biology: is the strongest evidence for
evolution. Not even known in Darwin’s time, it
involves comparing the DNA of different species to
determine their relatedness.
Just like our forelimbs or embryos are similar, so are
our genes.
Genes are also homologous structures.
So What is a Gene?
The
function
of transmit
DNA is to store
and transmit the
To store
and
the genetic
genetic
information
that tells
which
proteins
information
that tells
cellscells
which
proteins
to
when
to make
themthem
tomake
makeand
and
when
to make
Great Example: Hox Genes are
similar in all animals
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Professor Richard Dawkins
at the University of
Nebraska State Museum
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Dr. Kenneth Miller
compares ape and human
chromosomes
Human chromosome #2
and its ape analogs
1.
Traits in a population of organisms exhibit variation.
2.
In any given population, not all individuals survive to
reproduce.
3.
Survival is NOT random. Survivors must have an
advantage over those that don’t survive. A favorable trait
gives the organisms an adaptive advantage.
4.
The survivor’s advantageous traits MUST be heritable.
High fitness means an organism’s ability to reproduce
successfully.
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[email protected]
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1. The population or individual does not "want" or "try" to evolve,
and natural selection cannot try to supply what an organism
"needs." Natural selection just selects among whatever variations
exist in the population. The result is evolution.
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From www.evolution.berkeley.edu
Over many generations
in the dark, the species
has lost its eyes since
vision no longer gave the
fish an advantage.
Natural selection has no
foresight, if the light
returns to their
ecosystem, they will be at
a disadvantage.
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2. Natural selection is sometimes interpreted as a random
process. The genetic variation that occurs in a population because
of mutation is random — but selection acts on that variation in a
very non-random way: genetic variants that aid survival and
reproduction are much more likely to become common than
variants that don't. Natural selection is NOT random!
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From www.evolution.berkeley.edu
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There is also an excellent Brainpop
on Natural Selection
University of California Museum of Paleontology and the National
Science Foundation
http://evolution.berkeley.edu/
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Life on Earth is one big extended family
http://www.evogeneao.com/for-teachers/for-teachers.htm
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Dr. Dawkins’ videos on comparing the human and chimpanzee genome
and on transitional fossil
http://explore-evolution.unl.edu/dawkins.html
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Dr. Miller’s video clip on ape and human chromosomes
https://www.youtube.com/watch?x-ytcl=85114404&v=8FGYzZOZxMw&x-yt-ts=1422579428#t=102
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Cosmos Series, Episode 2, Dr. Neil Degrasse Tyson
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TEDx Misonceptions about Natural Selection
(https://www.youtube.com/watch?v=mZt1Gn0R22Q
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Your Inner Fish, Dr. Neil Shubin
(“Your Inner Fish” is on Netflix!!!)
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Evolution, The Story of Life on Earth,
Dr. Jay Hosler
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The Ancestor’s Tale, Dr. Richard Dawkins
Distribution of classroom resources!!!!
(powerpoints, labs, exam and exam reviews)
 A closer look at valuable online resources
 Hands-on activities
 A Preview of future museum exhibits
 Guest Speakers:
 Dr. Eldridge Birmingham, chief scientist and evolutionary biologist
at the Phillip and Patricia Frost Museum of Science
 Karlisa Callwood, PhD student, with an inquiry-based approach to
exploring evolution concepts
 Dr. Sean Duran, Philip and Patricia Frost Museum of Science,
discussing the Xiphactinus fossil restoration at the museum
 Mario Junco, www.explorelearning.com representative for online
science resources
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On pg. 43 of Your Inner Fish, Dr. Neil Shubin writes,
“Do the facts of our ancient history mean that humans
are not special or unique among living creatures? Of
course not. In fact, knowing something about the
deep origins of humanity only adds to the remarkable
fact of our existence: all of our extraordinary
capabilities arose from basic components that
evolved in ancient fish and other creatures. From
common parts came a very unique construction. We
are not separate from the rest of the living world; we
are part of it down to our bones and…even our
genes.”