Post on 23-Mar-2022
EVIDENCE OF EVOLUTION STATIONS
Station 1: Fossil Records
1. First, write the scientific definition of the following key terms in your NB, under the headingFossil Records, write definitions in your own words but be sure not to leave out importantparts.
Fossil __________________________________________________________________________Sedimentary rock _________________________________________________________________Natural selection__________________________________________________________________
Next, examine the diagram (left) to answer the questions below in complete sentences.
2. Explain whatthis diagram iscommunicating.
3. Is thisdiagram showingdirect evidenceor an inferencebased onreasoning?Explain.
This diagram shows insects and a lizard trapped in fossilized tree sap (amber) from millions of years ago and how they look today.
4. Explain how organismscould not change over timeand natural selection stillbe true and happening?
EVIDENCE OF EVOLUTION STATIONS
Which layers are oldest?
Can you put them in order from youngest to oldest?
EVIDENCE OF EVOLUTION STATIONS
Station 2: Descent with modification
Examine the diagrams and descriptions in the table about horse evolution on the back and use that information to answer the questions in complete sentences in your NB
1. Define: Descent with modification2. Hyracotherium lived in a dense forest area dominated by a rich undergrowth of ferns.
Discuss why the small body size might be an advantage in this type of environment?
3. A change in vegetation from dense forest to grasslands occurred due to climate changes andthis selected for changes in the shape of the horse’s leg and body size. Explain how thesechanges in vegetation could lead to the evolution of the horse.
4. The teeth of the browsers* (such as Mesohippus) were covered with a thick layer of enamel(hard outer-coating of teeth). The teeth of the modern-day horses, by comparison, have lessenamel and appear to be much wider and flatter. Provide scientific reasoning to explainthese changes seen in horse teeth over time.
*Browsers vs. Grazers: Browsers strip off and eat leaves, bark, and green stems from plants, while grazers clip vegetation like grasses ator near ground level. Deer, such as white-tailed deer in the Rocky Mountains, are browsers. The disadvantage of browsing is thatheight may make vegetation inaccessible (hence the long neck of the browsing giraffe), and often-times browsers eat parts of thevegetation that are low in nutrients, chemically defended (bitter/poisonous), or both. Grazers, such as sheep and cattle, can feed on themuch more nutrient-rich grasses.
Examine the images of modern horse variations at left.
5. All of thesevariations have comeabout in the last4,000 to 6,000 yearsas humansdomesticated horsesfor work, travel, andshow. Explain how allof these variationscan happen in such arelatively short periodof time whenprevious changestook millions ofyears.
EVIDENCE OF EVOLUTION STATIONS
Time frame
Diagram Description of horse
Equ
us
mo
der
n-d
ay h
ors
e
This horse lives in the grassy plains area
It eats grasses and is classified as a grazer
It is approximately 1.6 m (5.2 ft.) tall
It has a single visible digit
Plio
hip
pu
s 1
.6 m
illio
n y
ears
ago
This horse lived in areas with shrubs andon the grassy plains
It ate grasses and is classified as a grazer
It was approximately 1.0 m (3.2 ft.) tall
It had a single visible digit
Mer
ych
ipp
us
5 m
illio
n y
ears
ago
This horse lived in areas with shrubs andon the grassy plains
It ate leafy vegetation and grasses and isclassified as a grazer
It was approximately 1.0 m (3.2 ft.) tall
It has three visible digits
Mes
oh
ipp
us
24
mill
ion
yea
rs a
go
This horse lived in thinly wooded areas.
It ate leafy vegetation and is classified asa browser
It was approximately the size of a smalldog, about 0.6m (2 ft.) tall
It had four visible digits
Hyr
aco
ther
ium
3
7 m
illio
n y
ears
ago
This horse lived in thickly wooded areas
It ate leafy vegetation and is classified asa browser
It was approximately the size of a smalldog, about 0.4 m (1.3 ft.) tall
It had four visible digits
EVIDENCE OF EVOLUTION STATIONS
Station 3: Vestigial structures
Examine the diagrams and visuals below with your group. Based on your observations and discussion, answer the following questions in complete sentences.
1. Write a definition of a vestigial structure.2. Name 3 vestigial organs that humans have and hypothesize what their purpose probably was.3. Explain why snake legs are vestigial.4. Explain the scientific reasoning of how a vestigial organ is evidence of evolution.
Snakes evolved from four legged animals similar to lizards.Most species of snakes have lost all traces of limbs but snakes in the boa and python family have a tiny pair of hind legs. Unlike whales, the python's (or boa's) vestigial legs can actually be seen as a pair of "spurs" that stick out where the body ends and the tail begins. (Admittedly, it is difficult for an untrained person to tell where that is!)
The vermiform appendix had digestive functions in the ancestral human species, probably helping the cellulose in grass breakdown in the intestine, as they were herbivours. The appendix has become vestigial in human beings because they have become very small in size and don’t contribute in cellulose fermentation. However, several appendix problems occur in people and the removal of this part in the body will do no harm and is relatively common.
Whales still have bones (not seen from outside) that are remnants from hind legs.
EVIDENCE OF EVOLUTION STATIONS
Station 4: Comparative Anatomy & Homologous Structures
Analyze the diagram above then answer the following questions in complete sentences after discussing with your group.
1. Describe how the limbs of these seven organisms are similar and how are they different.
2. Explain why they are so similar in structure and yet can be used differently by the organism?How did this happen?
3. What does this help explain about how related ornot these species are to each other?
4. Explain how these structures are evidence ofevolution.
This picture of bones is from a seal fin I found on the beach. My own piece of evidence collected from a backpacking trip to the Lost Coast
in Northern California, summer 2013 (Me and a member of the Pinniped family (seals) both gesturing for world peace).
EVIDENCE OF EVOLUTION STATIONS
Station 5: Comparative Embryology
Examine the diagrams of four different vertebrate organisms at the early embryo stage. Discuss differences with your group and then answer the questions in complete sentences.
1. Try to determine which embryo will develop into which organism- reptile, human, bird, fish.2. Which ones out of the four do you think are most closely related, and why?3. After reading the passage below, construct an explanation for which animal is more closely
related to humans- chickens or fish? (put answer in CER format, complete sentences)Claim:Evidence:Reasoning:
EVIDENCE OF EVOLUTION STATIONS
Station 6: Genetic Evidence Gene sequence & protein sequences comparisons DNA is the code for making proteins, the closer the DNA, the closer the amino acid sequence, and thus the closer the final proteins are.
Analyze the following data with your group:
Amino Acid Sequences
Baboon ASN THR THR GLY ASP GLU VAL ASP ASP SER PRO GLY GLY ASN ASN
Chimp SER THR ALA GLY ASP GLU VAL GLU ASP THR PRO GLY GLY ALA ASN
Lemur ALA THR SER GLY GLU LYS VAL GLU ASP SER PRO GLY SER HIS ASN
Gorilla SER THR ALA GLY ASP GLU VAL GLU ASP THR PRO GLY GLY ALA ASN
Human SER THR ALA GLY ASP GLU VAL GLU ASP THR PRO GLY GLY ALA ASN
1. For each primate in the table above, count the number of amino acids that are different fromthe human sequence. Record these numbers in a data table on your handout, draw one likethe one shown below.
2. Calculate the percentage of differences of each primate compared to humans by dividing thenumber of amino acid differences by 15 and then multiplying by 100. Record these numbersin the data table you drew as well.
Primate # of Amino Acids
Different from Humans
Percent Difference
Baboon
Chimpanzee
Gorilla
Lemur
3. Use this data to create a graph to better communicate your findings. Remember which graphtype is good for comparing categories? Include title, label each axis with “x” and “y” AND thelabel (category/unit), make a key, include an appropriate scale.
4. Are your results surprising? Why or why not?
EVIDENCE OF EVOLUTION STATIONS
Chromosome comparisons: Another line of genetic evidence
5. Summarize the argument: whatevidence exists that humans andgreat apes shared a commonancestor?
EVIDENCE OF EVOLUTION STATIONS
Station 7: Biogeography
1. Define Biogeography2. Define a species3. How did these three members of the camel family become different species?Claim:Evidence:Reasoning:
EVIDENCE OF EVOLUTION STATIONS
Biogeography Cont. Endemism is the ecological state of a species being unique to a defined geographic location, such as an island, nation, country or other defined zone, or habitat type; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere.
Madagascar—an island off the coast of Africa—has some of the world's most interesting animals. About 75 percent of the species found in Madagascar are endemic, found nowhere else on the planet.
1.) What kind of selection would be responsible for giving rise to so many different species on this one island? Would it be a different kind of selection for just the endemic species? What is doing the selecting?
EVIDENCE OF EVOLUTION STATIONS
Station 8: Evolution of a Scientific Theory Building Ideas to Explain How Evolution Happens
1.) Science is a communal effort- which scientists laid the foundation for Darwin’s theory of natural selection? What ideas did they contribute that were crucial for Darwin to build on? (see back side) 2.) What do we know now about DNA and genetics that further disproves LaMarck’s theory? 2.) Are humans subject to natural selection? Does our human population have all 4 required factors?