Download Essential Idea: There is overwhelming evidence for the evolution of

DPTopic5.1:
Evidencefor
Evolution
Essential Idea: There is overwhelming evidence for the evolution of life on earth
WhatisEvolution?
Exercise1:indicatewhethereachfollowingstatementistrueorfalse,intermsofhow
youthinkbiologistsuseandunderstandtheterm"evolution"today.YOUdoNOThave
to AGREE with the statement for it to be "true". Your answers will not affect your
grade.Ineverycasebelow,"evolution"means"biologicalevolution".
WriteTorFnexttoeachstatement
1. Evolution is as much a fact as the fact that planets go around the Sun.
2. Evolution is something a person should either believe in, or not believe in.
3. Evolution is a process that includes the origin of life.
4. Evolution is primarily concerned with the origin of humans.
5. According to evolution, people came from monkeys a long time ago.
6. Evolution was first proposed and explained by Charles Darwin.
7. Evolution is also known as "Natural Selection".
8. Evolution is something that happened only in the past; it is not happening now.
9. Evolution is something that happens to individual
organisms.
10. Evolution is a totally random process, a series of accidents.
11. Evolution was developed as an idea to destroy or undermine religion.
12. In order to accept evolution as a real process, you cannot believe in God.
13. Most major religions in America have officially declared that they have NO
conflict with evolution.
14. Evolution simply means “change.”
15. Evolution is only a theory.
16. Evolution is like a chain, with each group of organisms evolving into the next
“link” in the chain.
17. There are many transitional fossils, with traits intermediate between different
groups, as expected if evolution happened.
18. Fossils reveal many problems that evolution cannot explain.
19. Biological, medical and agricultural research increasingly assumes that
evolution occurs.
20. Evolution has been tested and challenged many times, but has always been
supported by the results.
21. Big dinosaurs were common during the time of early humans.
22. Evolution involves individuals changing in order to adapt to their environment.
23. According to evolution, new species usually result from major mutations in a
single generation.
24. Most of the major groups of animals suddenly appeared in the “Cambrian
Explosion.”
25. The formation of complex structures, like the eye, can now be easily explained
by evolution.
Exercise2:Biologistsdefineevolutionintermsofachangeinthegenesandallelesof
groupsofindividualsofthesamespecies.Trytofillintheblanksbelow….
A gene is a
(2 words) that influences
An allele is an alternative
.
of a gene.
While groups of individuals of the same species can also be referred to as a
Based on what you have just written, can you define evolution? Have a go on the
lines below:
TheEvidenceforEvolution
Exercise3:Watchtheclearlystatedvideoandanswerthefollowingquestions
Give a textbook definition of evolution
Biologists claim that each branch of the evolutionary tree can be traced back
to a single shared ancestor.
What is the shared ancestor of whales and dolphins thought to be?
Evidence for evolution often uses comparison of features. Family members are
assumed to share similar features.
Describe three features of whales and dolphins which are also shared by land
mammals.
One particularly striking similarity is the composition of bones in the limbs of
whales dolphins and land mammals.
Describe the structure of bones in the pentadactyl limb found in all vertebrates.
Why is this called a homologous feature?
Why does this suggest that all vertebrates share a common ancestor?
Sometimes examples of species which are intermediate steps in a gradual
process of change between two animals can be found in the fossil record. These
species may have become extinct, but even if they haven’t the fossils can show
how the animals looked many years ago. This can provide further evidence of
the accumulation of gradual changes in the heritable characteristics of a
species.
Describe the features of Basilosaurid whales which provide evidence to link
modern land mammals to modern whales and dolphins.
Describe how a long line of fossils showing gradual changes in body anatomy from
ancient ‘walking whales’ to modern day whales supports the theory of evolution, as
a ‘cumulative change in the heritable characteristics of a species’.
DNA comparisons can also provide evidence about how closely related two
species are. An accumulation of changes in observable heritable features must
link to changes in the DNA.
Evidence for changes in characteristics in modern animals also provides
strong evidence for the mechanism of evolution. There are many breeds of
domesticated animals from cattle to dogs which illustrate this nicely.
Describe what happens in the selective breeding of farm animals, giving one
example.
Explain how this example supports the theory of evolution.
Name four lines of evidence for evolution and for each one explain how the
evidence supports the idea that species have evolved.
Pentadactyllimb
Comparethestructureofthepentadactyllimbofmammalsbelow.Howisitadapted
ineachgrouptothefunctionoflocomotion?
Speciation
Populations of a species can gradually diverge into separate species by evolution
Speciation is the formation of a new species by the splitting of an existing one. It
requires the following:
1. Isolation of populations
2. Changes in the alleles that each population has
Evidencefromcontinuousvariation
Many species show geographic variation across their populations. The populations
are recognizably different but not to the extent that they are clearly separate
species. One example of this is Lagopus lagopus
What does the existence of continuous variation across the geographic range of a
species tell us about evolution?
PepperedMothSimulation
Objective: Simulate changes in moth population due to pollution and predation, and
observe how species can change over time.
Introduction:
Charles Darwin accumulated a tremendous collection of facts to support the theory
of evolution by natural selection. One of his difficulties in demonstrating the theory,
however, was the lack of an example of evolution over a short period of time, which
could be observed as it was taking place in nature. Although Darwin was unaware of
it, remarkable examples of evolution, which might have helped to persuade people
of his theory, were in the countryside of his native England. One such example is
the evolution of the peppered moth Biston betularia.
The economic changes known as the industrial revolution began in the middle of the
eighteenth century. Since then, tons of soot have been deposited on the country
side around industrial areas. The soot discoloured and generally darkened the
surfaces of trees and rocks. In 1848, a dark-coloured moth was first recorded.
Today, in some areas, 90% or more of the-peppered moths are dark in colour. More
than 70 species of moth in England have undergone a change from light to dark.
Similar observations have been made in other industrial nations, including the
United States.
Instructions:
Click the link below to read more
information on Kettlewell's study
of moths. At the end, you will run
two simulations for 5 minutes
each, during this time you will
play the part of a bluejay that eats
moths.
After 5 minutes record the % of
dark moths and light moths - you
will need this information later.
Peppered Moth Simulation at peppermoths.weebly.com
Data and Analysis
Read the background information and answer the questions as you go.
Life Cycle of the Peppered Moth
1. Why are these moths called "peppered moths?"
2. What animals eat the peppered moth?
3. What is a lichen?
4. What do the larvae of the moth eat?
5. How do peppered moths spend the winter?
6. Moths that have more dark spots than the average moth are called what?
Impact of Pollution
7. Where was the virst black form of the moth found?
8. What was the Industrial Revolution?
9. What was causing the different colors in the moths?
10. What is natural selection?
11. Who suggested that peppered moths were an example of natural selection?
12. What is industrial melanism?
Kettlewell's Experiments
13. What is an entomologist?
14. How do scientists test theories?
15. Write down ONE of Kettlewell's predictions.
16. Dark moths were found in what parts of the country?
17. How did Kettlewell directly study the moths?
18. Why did dark moths have a survival advantage?
19. When Kettlewell recaptured the marked moths, what did he find?
20. Where did Kettlewell publish his findings?
Birdseye View
21. Open the simulation and play the role of the bird in both the dark and the light
forest. Try to behave as a bird would behave, choosing the moths that are the most
obvious. At the end of each simulation, record the percent of moths captured in the
table below.
Final Analysis
22. Explain how the color of the moths increases or decreases their chances of
survival.
23. Explain the concept of "natural selection" using your moths as an example.
24. What would happen if there were no predators in the forest? Would the colors of
the moths change over time? Defend your answer?
Core
Biology guide
Topic 5: Evolution and biodiversity
12 hours
Essential idea: There is overwhelming evidence for the evolution of life on Earth.
5.1 Evidence for evolution
Nature of science:
Looking for patterns, trends and discrepancies—there are common features in the bone structure of vertebrate limbs despite their varied use. (3.1)
Understandings:
Theory of knowledge:
t
Evolution occurs when heritable characteristics of a species change.
t
t
The fossil record provides evidence for evolution.
t
Selective breeding of domesticated animals shows that artificial selection can
cause evolution.
t
Evolution of homologous structures by adaptive radiation explains
similarities in structure when there are differences in function.
t
Populations of a species can gradually diverge into separate species by
evolution.
t
Continuous variation across the geographical range of related populations
matches the concept of gradual divergence.
Applications and skills:
t
Application: Development of melanistic insects in polluted areas.
t
Application: Comparison of the pentadactyl limb of mammals, birds,
amphibians and reptiles with different methods of locomotion.
Evolutionary history is an especially challenging area of science because
experiments cannot be performed to establish past events or their causes.
There are nonetheless scientific methods of establishing beyond reasonable
doubt what happened in some cases. How do these methods compare to
those used by historians to reconstruct the past?
Utilization:
Syllabus and cross-curricular links:
Physics
Topic 7.1 Discrete energy and radioactivity
Geography
Part 1.3 Patterns in environmental quality and sustainability/Biodiversity and
change
Environmental systems and societies
Topic 4 Biodiversity in ecosystems
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