Binni Chadda & Amy Woolf
Sean B. Carroll, Into The Jungle: Great Adventures in the Search for Evolution – Grade 10, Biology
Published in San Francisco, California: Benjamin Cummings, 2008.
Learning Objective:
The goal of this two-day lesson is to give students a better understanding of evolution and the concept of survival of the fittest.
Students typically learn about evolution from science textbooks and stories about Charles Darwin, his voyage on the Beagle and his
observations of finches on the Galapagos Islands. This exemplar text exposes students another, less familiar,
naturalist/biologist/geographer, Alfred Russel Wallace, and his thought process that led to his discovery of the “survival of the fittest”
theory. Through close reading of this text, students will acquire new vocabulary and engage in discussions and activities that will
enhance their understanding of evolution. They will think about animals that they are familiar with and how their traits and
characteristics make them “fit” and thrive in their environment. Through the culminating writing assignments, students will make
connections between the works of Darwin and Wallace and the importance of collaboration in research.
Reading Task:
The reading will be divided into two parts. On the first day of the lesson, students will read the section titled
“Drawing the Line” in two parts. After reading (and discussing) Part One, they will develop their own theories and
ideas about Wallace’s discoveries. Part Two of Day One gives students the solution and will tell them if their
theories were correct. The second day of the lesson will begin with a review of the readings from the first day. An
optional re-read of Day One’s passages may occur before the review of the first day’s activities if the teacher deems it
necessary for students’ understanding and comprehension of the material. Independently, students will read the second
section, “Survival of the Fittest” of the selected text and annotate when necessary, prior to engaging in discussions and
activities about the text.
Vocabulary Task:
Most of the meanings of the words in the text can be learned from a thoughtful reading of the context in which
they appear. Students must engage in the practice of discovering word meanings from contextual clues, however,
at times, help is needed. Brief definitions of the more challenging words (underlined in the text) are provided for
students in a separate column to the right of the text. Academic words are in bold to draw attention to them
during instruction and subsequent class discussions. In this particular selection, the academic, content-specific
vocabulary conjures up mental images of animals on the island, the separation between the landmasses, etc. which
Binni Chadda & Amy Woolf
can help students visualize Wallace’s observations and findings and the research process.
Sentence Syntax Task:
Even though the selected passage contains academic vocabulary, the sentence structure, tone and message are
less technical and easier to understand than if students were reading about the same topic in a science textbook.
For all readings, teachers should allow students enough time to read the text, deconstruct particularly difficult
sentences and address any nuances specific to the exemplar text. The teacher will advise students to be creative
and use their imagination when reading this text. The description of Wallace’s adventures and inner dialogue can
create vivid images of his observations, discoveries and thought processes in their minds which will help their
increase their understanding. The teacher will assess students’ comprehension by walking around the classroom
and listening to their discussions during the activities, allowing time to assist individual students as needed.
Discussion Task:
Throughout the two days, students will have several opportunities to discuss the selection in depth with their
teacher and classmates (in small groups and as a class). Many of the questions under discussion require evidence
from the text which helps build their understanding of the text.
Writing Task:
Students will write an essay comparing and contrasting the works of Darwin and Wallace, citing evidence from the
exemplar text and the textbook or their prior background knowledge if this selection is used as an introduction to
evolution. Wallace sent his paper about “survival of the fittest” to Darwin (who, at the time, was working on a
similar theory) before submitting it to a journal, so the second writing assignment will focus on the importance of
collaboration as an essential part of research. Students will have the opportunity to participate in classroom
discussions and share their thoughts and ideas and receive feedback from both the teacher and classmates.
Text Selection:
This excerpt was taken from Sean B. Carroll’s Into The Jungle: Great Adventures in the Search for Evolution and consists of two sections
(“Drawing the Line” and “Survival of the Fittest”). Though it is not necessary for students to have covered evolution in class, this text is a
valuable complement to classroom instruction and activities about evolution, adaptations and “survival of the fittest”. Findings and
observations from another researcher’s adventures are presented, and students are able to access prior knowledge for a more in-depth
understanding of the theory of evolution.
Binni Chadda & Amy Woolf
Outline of Lesson Plan:
This lesson is divided into two days of instruction, questions and reflection. On Day One, the first section, “Drawing the Line,” of the
selected text is divided into two parts. Students will read, annotate and answer questions and formulate theories (as a class and in small
groups) about Part One. Students will read Part Two of “Drawing the Line” to check their theories developed during the discussion of Part
One. Day Two will begin with a review of the readings from Day One. Students will read the second section, “Survival of the Fittest” of the
exemplar text and engage in small group and class discussions as well as complete two short writing assignments.
Standards Addressed:
The following Common Core State Standards are the focus of this exemplar: RST.9-10.2, RST.9-10.6, RST.9-10.7, RST.9-10.8, RST.910.9, L.9-10.4, L.9-10.6, W.9-10.2 and W.9-10.9.
RST.9-10.2:
Determine the central ideas or conclusions of a text; trace the text’s explanation or depiction of a complex process,
phenomenon, or concept; provide an accurate summary of the text.
RST.9-10.6:
Analyze the author’s purpose in providing an explanation, describing a procedure, or discussing an experiment in a text, defining
the question the author seeks to address.
RST.9-10.7:
Translate quantitative or technical information expressed in words in a text into visual form (e.g., a table or chart) and translate
information expressed visually or mathematically (e.g., in an equation) into words.
RST.9-10.8:
Assess the extent to which the reasoning and evidence in a text support the author’s claim or a recommendation for solving a
scientific or technical problem.
RST.9-10.9:
Compare and contrast findings presented in a text to those from other sources (including their own experiments), noting when
the findings support or contradict previous explanations or accounts.
Binni Chadda & Amy Woolf
L.9-10.4:
Determine or clarify the meaning of unknown and multiple-meaning words and phrases based on grades 9–10 reading and
content, choosing flexibly from a range of strategies.
L.9-10.6:
Acquire and use accurately general academic and domain-specific words and phrases, sufficient for reading, writing, speaking,
and listening at the college and career readiness level; demonstrate independence in gathering vocabulary knowledge when
considering a word or phrase important to comprehension or expression.
W.9-10.2:
Write informative/explanatory texts to examine and convey complex ideas, concepts, and information clearly and accurately
through the effective selection, organization, and analysis of content.
W.9-10.9:
Draw evidence from literary or informational texts to support analysis, reflection, and research.
Binni Chadda & Amy Woolf
The Text: Carroll, Sean B. Into The Jungle: Great Adventures in the Search for Evolution
(Excerpt from Chapter 2: Drawing the Line Between Monkeys and Kangaroos)
Exemplar Text
Vocabulary
Drawing a Line
Wallace went island-hopping quite often. He made ninety-six journeys totaling about fourteen thousand
miles and visited some of the same islands several times over in the span of eight years. Often the
availability, or unavailability, of a boat determined his path. He had to be flexible. He tried several times
to get from Singapore to Makassar on the island of Sulawesi. No luck. But one day in May 1856, he did
find a Chinese schooner headed to Bali, which he had no intention of visiting, but he could find a way
from there to Lombok and then on to Makassar. This accidental detour would give Wallace the most
important discovery of his expedition.
On Bali, Wallace found a similar variety of birds as on the other islands he had visited – a weaver, a
woodpecker, a thrush, a starling – nothing too exciting. But then, he later recalled, “crossing over to
Lombok, separated from Bali by a strait less than twenty miles wide, I naturally expected to meet with
some of these birds again; but during a stay there of three months I never saw one of them.” Instead,
Wallace found a completely different assortment of birds – white cockatoos, three species of honeysuckers, a loud bird the locals called a “Quaich-Quaich,” and a really strange bird called a megapode
(meaning “big foot”) that used its big feet to make very large mounds for its eggs. None of these groups
were known on the western islands of the archipelago – Java, Sumatra, Malaysia, or Borneo. Now here
was a puzzle. What constraint prevented the spread of these species from island to island? Surely, birds
could cover a twenty-mile strait with little trouble.
sailing vessel
roundabout way or course
narrow, navigatable waterway
that connects two larger,
navigatable bodies of water
island group or chain
restriction
It was as if, Wallace wrote in a letter to Bates, there was some kind of “boundary line” between Bali and
Lambok (Figure 2.4 map). Traveling further east to Flores and Timor, the Aru Islands, and New Guinea, the
changeover in bird life was very clear. All of the families of birds that were common on Sumatra, Java, and
Borneo were absent from Aru, New Guinea, and Australia, and vice versa.
The differences in mammals among the western and eastern islands of Indonesia were just as striking. On
the large western island there were monkeys, tigers, and rhinoceros. But on Aru there were no primates or
carnivores, all of the native mammals were marsupials – a kangaroo, three or four species of cuscus, and
some other small rat-like marsupials.
possum
Binni Chadda & Amy Woolf
Exemplar Text
That line between Bali and Lombok was real, and signified something very profound to Wallace. He put his
thoughts to paper again (published in 1857).
Let us now examine if the theories of modern naturalists will explain the phenomena of Aru and
New Guinea fauna…How do we account for the places where they came into existence? Why are
not the same species founds in the same climates all over the world? The general explanation
given is, that as the ancient species became extinct, new ones were created in each country or
district, adapted to the physical conditions of that district.
Vocabulary
having intellectual depth and
insight
occurrence (can be impressive or
extraordinary)
animal life in a region
By created, Wallace meant “specially created by a Creator.” But, Wallace pointed out, a theory of creation
would make us expect to find similar animals in countries with similar climates, and dissimilar animals in
countries with dissimilar climates. This is not at all what he saw.
Comparing Borneo (in the west) and New Guinea (in the east), Wallace remarked, “It would be difficult to
point out two countries more exactly resembling each other in climate and physical features.” But, in fact,
the regions’ birds and mammals were entirely different.
Comparing New Guinea and Australia, Wallace wrote, “We can scarcely find a stronger contrast than their
physical conditions…one enjoying perpetual moisture, the other with alternatives of drought.” Wallace
reasoned,
barely, hardly
never ending, constant
If kangaroos are especially adapted to the dry plains and open woods of Australia, there must be
some other reason for their introduction into the dense damp forest of New Guinea, and we can
hardly imagine that great variety of monkeys, squirrels, of Insectivores, and Felidae [cats], were
created in Borneo because the country was adapted to them, and not one single species given to
another country exactly similar and at no great distance.
In the tropical forest of the eastern islands, tree kangaroos occupied the habitat by monkeys in the west.
[END PART ONE OF TEXT]
The reason for the observed differences in animal distributions, Wallace concluded, must be that “some
other law regulated the distribution of existing species.” That other law, Wallace suggested, was the
Sarawak Law, which he had proposed two years earlier. Again Wallace relied on geology to make his case.
controlled
Binni Chadda & Amy Woolf
Exemplar Text
He surmised that New Guinea, Australia, and Aru must have been connected at some time in the past and
that such a connection would explain why those landmasses shared similar sets of birds and mammals.
And the western islands of Indonesia? Wallace deduced they had once been part of Asia, and so shared the
tropical fauna – monkeys, tigers, and so forth – of Asia.
Wallace was right. The distance between Bali and Lombok is short, but the ocean separating them was
later discovered to be very deep. Bali lies just on the edge of the continental shelf, while Lombok lies just
off it (see Figure 2.4). Bali was once connected to the other western islands of Indonesia, but never to
Lombok. For animals living on one island, it wasn’t simply a matter of flying or swimming the twenty miles
to the next island. For millions of years the separation was much greater, and so animals adapted to the
conditions peculiar to each island. The islands are close together today, but they are, geologically speaking,
“new neighbors.”
Vocabulary
infer , make a guess
strange, odd, unusual
Wallace linked the question of origin of species to how species were distributed. He defined a dividing line
between the fauna of Asia and Australia. His discovery would be forever known as the “Wallace Line” (see
Figure 2.4), and Wallace himself would be known as the founder of biogeography.
Survival of the Fittest
The question for Wallace was now not if species evolved, but how? Baking in a malarial fever on the
volcanic island of Temate in early 1858, the answers came to him.
Alternating between hot and cold fits, Wallace had to rest. He had nothing to do, he recalled, but “to think
over subjects then particularly interesting to me.” Wrapped in a blanket on an 88°F day, he thought of
Malthus’ essay on population, which he had read some years earlier. It occurred to him that maladies similar
to disease, accidents, and famine that check the growth of human populations check the populations of
animals, too. He thought about breeding, how animals bred much more rapidly than humans, and that if left
unchecked, animals would overcrowd the world very quickly. But all of his experience revealed that animal
vigorous action or effort
populations were limited. “The life of wild animals,” Wallace concluded, “is a struggle for existence. The full
exertion of all their faculties and all their energies is required to preserve their own existence and provide
mental or physical power
for that of their infant offspring.” Wallace knew from a decade in the jungle that finding food and escaping
danger ruled animals’ lives – and the weakest were weeded out.
eliminated
Binni Chadda & Amy Woolf
Exemplar Text
Vocabulary
Wallace, the great collector, was intimately familiar with the variety of individuals of a species. He
continued, “Perhaps all the variations…must have some definite effect, however slight, in the habits of or
capacities of the individuals…a variety having slightly increased powers…must inevitably acquire a
superiority in numbers.”
Bingo. He had figured it out – either that or he was out of his mind. Wallace had to wait for his fever to
fade before he could make any notes. Then, he wrote the paper out in full in just a few nights.
He entitled the paper, “On the Tendency of Varieties to Depart Indefinitely From the Original Type.” Later
he would refer to the main idea expressed in this paper as “survival of the fittest” (a phrase borrowed
from the social scientist Herbert Spencer). Wallace’s paper was just a sketch, conceived in a dilapidated
house in an earthquake-ravaged island during bouts of fever, ten thousand miles from the center of
science in England. Wallace did not send it directly to a journal, he wanted others to look at it first.
He sent it to, whom else? Darwin.
This time, Wallace would not go unnoticed.
state of disrepair or ruin or
deterioration
a period of illness
Binni Chadda & Amy Woolf
Figure 2.4 The Wallace Line
Wallace discovered that the narrow strait between Bali and Lombok marked a boundary between Asiatic fauna (with tigers,
rhinoceri, and orangutans) and Australia-type fauna (with kangaroos, cuscus, and other marsupials). Bali was once connected to the
Asiatic continental shelf, but not to Lombok. The boundary line extends throughout the archipelago as shown.
Drawn by Leanne Olds.
Binni Chadda & Amy Woolf
Day One: Instructional Exemplar for Carroll’s Into The Jungle: Great Adventures in the Search for Evolution
Summary of Activities
1. Teacher introduces Part One of the passage and asks students to read it independently, having them annotate with a
pencil while they read. (5 minutes)
2. Teacher has class answer text dependent questions for Part One in form of notes or more formal response when
appropriate. Students will be asked initial questions as a class and then will split into small groups. (35 minutes)
3. Teacher hands out Part Two of text and Teacher or skilled reader reads until section titled “Survival of the Fittest” to
check student’s theories developed during discussion. (10 minutes)
Text Under Discussion
Wallace went island-hopping quite often. He made ninetysix journeys totaling about fourteen thousand miles and
visited some of the same islands several times over in the
span of eight years. Often the availability, or unavailability,
of a boat determined his path. He had to be flexible. He
tried several times to get from Singapore to Makassar on
the island of Sulawesi. No luck. But one day in May 1856,
he did find a Chinese schooner headed to Bali, which he
had no intention of visiting, but he could find a way from
there to Lombok and then on to Makassar. This accidental
detour would give Wallace the most important discovery
of his expedition.
On Bali, Wallace found a similar variety of birds as on the
other islands he had visited – a weaver, a woodpecker, a
thrush, a starling – nothing too exciting. But then, he later
recalled, “crossing over to Lombok, separated from Bali by a
strait less than twenty miles wide, I naturally expected to
meet with some of these birds again; but during a stay there
of three months I never saw one of them.” Instead, Wallace
found a completely different assortment of birds – white
cockatoos, three species of honey-suckers, a loud bird the
Directions for Teachers/Guiding Questions for Students
sailing vessel
roundabout
way or course
narrow,
navigatable
waterway that
connects two
larger,
navigatable
bodies of water
1. Hand out Part One of the passage and ask students
to read independently and annotate when
necessary.
Students should be instructed to annotate any
words that they do not understand as well as any
ideas from the text that they think are interesting. It
is not necessary for students to already have
covered evolution in class, however if they have
they will be better equipped with background
knowledge to apply to discussion questions and
make educated responses.
2. Students are asked discussion questions and asked
to answer them in the form of notes or short
answers.
Students will be asked initial understanding, text
dependent questions as a class, then move into
small group discussion for later questions to develop
theories.
Binni Chadda & Amy Woolf
Text Under Discussion
locals called a “Quaich-Quaich,” and a really strange bird
called a megapode (meaning “big foot”) that used its big feet
to make very large mounds for its eggs. None of these
groups were known on the western islands of the
archipelago – Java, Sumatra, Malaysia, or Borneo. Now here
was a puzzle. What constraint prevented the spread of these
species from island to island? Surely, birds could cover a
twenty-mile strait with little trouble.
Directions for Teachers/Guiding Questions for Students
island group or
chain
restriction
It was as if, Wallace wrote in a letter to Bates, there was
some kind of “boundary line” between Bali and Lambok
(Figure 2.4 map). Traveling further east to Flores and
Timor, the Aru Islands, and New Guinea, the changeover in
bird life was very clear. All of the families of birds that
were common on Sumatra, Java, and Borneo were absent
from Aru, New Guinea, and Australia, and vice versa.
The differences in mammals among the western and
eastern islands of Indonesia were just as striking. On the
large western island there were monkeys, tigers, and
rhinoceros. But on Aru there were no primates or
carnivores, all of the native mammals were marsupials – a
kangaroo, three or four species of cuscus, and some other
small rat-like marsupials.
That line between Bali and Lombok was real, and signified
something very profound to Wallace. He put his thoughts
to paper again (published in 1857).
possum
having
intellectual
depth and
insight
(Q1) As a class, ask students what kind of
challenges Wallace faced/would have faced being
an explorer in the 19th Century.
This question is designed to raise student’s
awareness of the challenges that faced scientists
and explorers that worked in the non-digital age.
Students may need a reminder that Wallace did not
have access to the Internet (a constant stream
information), traveling took a long time and was not
reliable, and he had to write letters to his mentors
and wait a long time for the responses. Refer back
to first paragraph for support.
(Q2) As a class, ask students to define carnivore
and then based on this definition have them infer
the definition of the word Insectivore, found later
in the reading. Also ask students to name an
animal that is a marsupial from the reading. Define
marsupial.
This question is designed to be an exercise for
students to apply background knowledge and
context in order to figure out the definition of a
word that they may not know. The other purpose of
this question is to have students recognize the many
varieties of animals that Wallace encountered and
how the animal populations varied from island to
island.
Binni Chadda & Amy Woolf
Text Under Discussion
Let us now examine if the theories of modern
naturalists will explain the phenomena of Aru and
New Guinea fauna…How do we account for the
places where they came into existence? Why are
not the same species founds in the same climates
all over the world? The general explanation given
is, that as the ancient species became extinct, new
ones were created in each country or district,
adapted to the physical conditions of that district.
Directions for Teachers/Guiding Questions for Students
occurrence
(can be
impressive or
extraordinary)
animal life in a
region
By created, Wallace meant “specially created by a Creator.”
But, Wallace pointed out, a theory of creation would make
us expect to find similar animals in countries with similar
climates, and dissimilar animals in countries with dissimilar
climates. This is not at all what he saw.
Comparing Borneo (in the west) and New Guinea (in the
east), Wallace remarked, “It would be difficult to point out
two countries more exactly resembling each other in
climate and physical features.” But, in fact, the regions’
birds and mammals were entirely different.
Comparing New Guinea and Australia, Wallace wrote, “We
can scarcely find a stronger contrast than their physical
conditions…one enjoying perpetual moisture, the other
with alternatives of drought.” Wallace reasoned,
barely, hardly
never ending,
constant
*Divide students into small groups for remaining
questions, and hand out final questions on a sheet
of paper with room for responses. Be sure that one
student fills the role of scribe.
(Q3) What are some reasons that animals migrate
or move from place to place? Discuss some
examples that you know of animals that migrate.
Do you know where they go? Is it a long distance or
a short distance?
This question functions as a lead up to the puzzle
presented in Q4. Hopefully students will be familiar
with a species that migrate and that migration
usually involves travel over a great distance.
Examples: Many birds go south for the winter to
follow food sources. Monarch butterflies migrate to
Mexico to follow the warm weather (and food).
(Q4) Wallace travelled to Bali by chance before he
traveled to Lambok, what was surprising to him
about the fauna (animals) in Lambok and why?
Wallace was intrigued by the fact that no species
that existed on Bali had made its way over to
Lambok, a mere 20 miles away (including bird
species). There seemed to be an invisible line
dividing the two nearby islands.
Binni Chadda & Amy Woolf
Text Under Discussion
If kangaroos are especially adapted to the dry
plains and open woods of Australia, there must be
some other reason for their introduction into the
dense damp forest of New Guinea, and we can
hardly imagine that great variety of monkeys,
squirrels, of Insectivores, and Felidae [cats], were
created in Borneo because the country was
adapted to them, and not one single species given
to another country exactly similar and at no great
distance.
In the tropical forest of the eastern islands, tree kangaroos
occupied the habitat by monkeys in the west.
Directions for Teachers/Guiding Questions for Students
(Q5) Discuss this quote from the passage: “Wallace
remarked, ‘It would be difficult to point out two
countries more exactly resembling each other in
climate and physical features.’ But, in fact, the
regions’ birds and mammals were entirely
different.”
Why is this puzzling? As a group come up with you
own theory as to why the animals on the two
islands were different.
Encourage students to support their theories with
either examples from the text or background
knowledge from class or other subjects. Prior to
handing out Part Two of the reading (which has the
answer to this question) have a few groups share
their theories with the class.
3. Teacher hands out Part Two of text (including map),
and it is read as a class to check students’ theories
developed during small group discussion.
Have students read the remainder of the text down to
Survival of the Fittest. This section will explain why
the animal species on the two islands were so
different, despite their proximity. Wrap up the class
with a brief explanation of Pangea and the concept
that the landmasses on Earth are constantly in
motion.
Binni Chadda & Amy Woolf
Day Two: Instructional Exemplar for Carroll’s Into The Jungle: Great Adventures in the Search for Evolution
Summary of Activities
1. Teacher reviews the activities from day one and asks students to share what they learned from the first reading.
(5 minutes)
2. Teacher asks students to read, independently, section two of the selection and annotate with a pencil as they read.
(5 minutes)
3. Teacher engages class in discussions, first in small groups and then as a class. (15 minutes)
4. Students are assigned two short writing tasks. (20 minutes)
Text Under Discussion
The reason for the observed differences in animal
distributions, Wallace concluded, must be that “some other
law regulated the distribution of existing species.” That
other law, Wallace suggested, was the Sarawak Law, which
he had proposed two years earlier. Again Wallace relied on
geology to make his case. He surmised that New Guinea,
Australia, and Aru must have been connected at some time
in the past and that such a connection would explain why
those landmasses shared similar sets of birds and
mammals. And the western islands of Indonesia? Wallace
deduced they had once been part of Asia, and so shared
the tropical fauna – monkeys, tigers, and so forth – of Asia.
Wallace was right. The distance between Bali and Lombok
is short, but the ocean separating them was later
discovered to be very deep. Bali lies just on the edge of the
continental shelf, while Lombok lies just off it (see Figure
2.4). Bali was once connected to the other western islands
of Indonesia, but never to Lombok. For animals living on
one island, it wasn’t simply a matter of flying or swimming
the twenty miles to the next island. For millions
Directions for Teachers/Guiding Questions for Students
controlled
infer , make a
guess
1. Review reading and activities from Day One.
To start Day Two, ask students to briefly discuss the
purposed of the reading from Day One and share
what they learned.
2. Take out section two of the text and ask students
to close read independently and annotate when
necessary.
The reading from Day One answered the questions
do species evolve (yes) and why. The purpose of Day
Two’s reading is to answer the “how”. In this
section, students will learn how Wallace came up
with the idea of “survival of the fittest.”
Binni Chadda & Amy Woolf
Text Under Discussion
of years the separation was much greater, and so animals
adapted to the conditions peculiar to each island. The
islands are close together today, but they are, geologically
speaking, “new neighbors.”
Directions for Teachers/Guiding Questions for Students
strange, odd,
unusual
(Q1) Refer to Figure 2.4 in your reading. What does
Wallace’s Line represent? Why are the animals
different on either side? What is an example of
animal migration that was controlled by
geography?
This question is partly for review and partly to see if
students can apply their knowledge from Social
Studies of human migration across the Bering Strait
into the Americas. This was an animal migration that
was made possible by changing sea levels.
Wallace linked the question of origin of species to how
species were distributed. He defined a dividing line
between the fauna of Asia and Australia. His discovery
would be forever known as the “Wallace Line” (see Figure
2.4), and Wallace himself would be known as the founder
of biogeography.
Survival of the Fittest
The question for Wallace was now not if species evolved,
but how? Baking in a malarial fever on the volcanic island of
Temate in early 1858, the answers came to him.
Alternating between hot and cold fits, Wallace had to rest.
He had nothing to do, he recalled, but “to think over
subjects then particularly interesting to me.” Wrapped in a
blanket on an 88°F day, he thought of Malthus’ essay on
population, which he had read some years earlier. It
occurred to him that maladies similar to disease, accidents,
and famine that check the growth of human populations
check the populations of animals, too. He thought about
breeding, how animals bred much more rapidly than
humans, and that if left unchecked, animals would
overcrowd the world very quickly. But all of his experience
revealed that animal populations were limited. “The life of
wild animals,” Wallace concluded, “is a struggle for
existence. The full exertion of all their faculties and all their
energies is required to preserve their own existence and
3. Divide students into small groups or pairs. Ask them
to take notes about what was discussed in their
groups so they can share their thoughts in a larger
conversation with the class.
(Q2) What does Wallace mean by “survival of the
fittest?”
Animals with traits that are better suited
for/adapted to a particular environment will survive
and those favorable traits will be passed down to
future generations
vigorous action
or effort
mental or
physical power
Binni Chadda & Amy Woolf
Text Under Discussion
provide for that of their infant offspring.” Wallace knew
from a decade in the jungle that finding food and escaping
danger ruled animals’ lives – and the weakest were weeded
out.
Directions for Teachers/Guiding Questions for Students
eliminated
(Q3) What unique traits or adaptations does this
animal have? In what environment would it thrive?
In what environment would it be “weeded out?”
Wallace, the great collector, was intimately familiar with
the variety of individuals of a species. He continued,
“Perhaps all the variations…must have some definite effect,
however slight, in the habits of or capacities of the
individuals…a variety having slightly increased
powers…must inevitably acquire a superiority in numbers.”
This question asks students to think about animals
that are familiar to them and their traits and
environment and how that affects the survival.
Bingo. He had figured it out – either that or he was out of
his mind. Wallace had to wait for his fever to fade before
he could make any notes. Then, he wrote the paper out in
full in just a few nights.
He entitled the paper, “On the Tendency of Varieties to
Depart Indefinitely From the Original Type.” Later he would
refer to the main idea expressed in this paper as “survival
of the fittest” (a phrase borrowed from the social scientist
Herbert Spencer). Wallace’s paper was just a sketch,
conceived in a dilapidated house in an earthquake-ravaged
island during bouts of fever, ten thousand miles from the
center of science in England. Wallace did not send it
directly to a journal, he wanted others to look at it first.
He sent it to, whom else? Darwin.
This time, Wallace would not go unnoticed.
After a class discussion about survival of the fittest,
teachers will give each group a picture of an animal
(skunk, anteater, giraffe, cheetah, armadillo, etc.)
and students will answer the following questions:
Following a large group discussion about the
different animals, the class will proceed to the
writing assignments.
state of
disrepair or
ruin or
deterioration
a period of
illness
Binni Chadda & Amy Woolf
Writing Assignments: Directions for Teachers and Students/Guidance for Teachers
The following writing assignments are based on the excerpt from Sean B. Carroll’s Into The Jungle: Great Adventures in the Search
for Evolution:
Writing Assignment 1:
Create a chart similar to the one below and compare and Contrast Darwin and Wallace’s discoveries. Describe their voyages, the
animals they observed, their traits and adaptations, the environment, the effects of the environment on the survival of the species,
etc. Cite evidence from the textbook and the excerpt from Into The Jungle.
Charles Darwin
Alfred Russel Wallace
Writing Assignment 2:
Wallace wrote a paper about his discoveries and the idea of “survival of the fittest,” but before he submitted is paper to a journal,
he “wanted others to look at it first” and sent it to Charles Darwin, who, at the time, was engaged in similar discoveries and was
writing up his own theories.
Briefly answer the following question: Why is collaboration an important part of research?