Northside AP Biology
Homework Packet
HW
Weekly 1
Due before class starts on Wednesday, October 30, 2013.
Name: ________________________________Period: ________
IMPORTANT REMINDERS:
 SEND IN PICTURES FOR
THROWBACK THURSDAY
 REVIEW VOCABULARY!
 EXCHANGE OLD TEXTBOOKS FOR
NEW IF YOU HAVEN’T DONE SO
ALREADY
TOPICS FOR THE WEEK
COLONIZATION OF LAND BY PLANTS AND FUNGI, ANIMAL DIVERSITY, MASS
EXTINCTIONS, ADAPTIVE RADIATION, LAB POSTER PRESENTATIONS
Mr Burley
Readings and Questions:
CC = Concept Check SSE = Scientific Skills Exercise
Wednesday:
Reading: Skim Ch. 26, Read 27.1–27.2
Q: Ch.26
 CC 26.1 (2, 4)
 CC 26.2 (2)
 CC 26.3 (1, 2)
 CC 26.4 (1,3)
 CC 26.5 (1, 2)
Ch. 27
 CC 27.1 (1)
 CC 27.2 (1, 2)
Thursday
Reading: 27.3–27.4
Q: Ch. 27
 CC 27.3 (1, 2, 3)
 CC 27.4 (1, 2, 3)
Friday & Weekend
Reading: 27.5– Ch. 23 (all)
Q: Ch. 27
 CC 27.5 (1, 2, 3)
 SSE 27.5 (1 – 5)
Mr Burley
Ch. 23
 CC 23.1 (2, 5)
 CC 23.2 (1, 2, 3, 4)
 CC 23.3 (2)
 CC 23.4 (1, 2)
Monday
Reading: 40.1–40.3
Q: Ch. 40
 CC 40.1 (1, 2, 3)
 CC 40.2 (1, 3)
 CC 40.3 (1)
Tuesday
Reading: 40.4–40.6
Q: Ch. 40
 CC 40.4 (1, 2)
 CC 40.5 (1, 2, 3)
 CC 40.6 (1, 2)
 SSE 40.5 (1, 2, 3)
Mr Burley
Vocabulary:
PRACTICE VOCABULARY FOR CHAPTERS 19 – 27
Utilize the flashcard tool and other resources on the student media
CD to practice these words. Purposeful practice is the best way to
learn new vocabulary!
Annotation:
Using the system written below, identify the main ideas and points of
each article, the evidence supporting the idea, and any words that
you do not know.
 Main point or scientific claim - boxed
 Quantitative evidence (numbers or data) supporting the
scientific claim - underlined and hash tagged (#)
 Qualitative evidence (qualities or description) supporting the
scientific claim - underlined and starred
 Words that you do not know the meaning of - circled
 Write two questions you have in the margin
Fossil Scans Reveal Origins of Teeth
By Matt Kaplan and Nature Magazine
Which came first: fangs or bony armor? For years, paleontologists have thought that
the first bones to emerge were teeth, and that the protective armor coverings of early fish,
made of similar material, followed. But now, a study reveals that the truth is the other way
around.
Mr Burley
The work focuses on a group of ancient jawless animals known as conodonts, which
died out during the late Triassic period, about 200 million years ago. These eel-like
creatures lacked internal or external skeletons but their mouths had hard spurs that were
readily fossilized, and made of materials that look similar to dentine and enamel. Because
the teeth of fish, dogs, dinosaurs and humans are made of these materials, the long-standing
assumption, known as the inside-out hypothesis, has been that the hard structures inside
the conodont mouth were early teeth and that the exoskeletal armor that covered the first
fish later developed from these teeth-like structures.
Past work examining how some conodonts grew the hard spurs in their mouths
shows that it was startlingly similar to how modern animals grow teeth. The likenesses are
tantalizing, but the latest study's lead author, paleontologist Philip Donoghue at the
University of Bristol, UK, is arguing that it is all a grand evolutionary illusion.
Skin of the teeth
Using X-ray tomographic microscopy with laser-like synchrotron radiation, a
technique that reveals the internal structure and composition of fossils, Donoghue and his
team were able to analyze early conodonts to reveal how their tooth-like spurs evolved. They
report in Nature this week that the structures found in early conodonts evolved
independently from vertebrate teeth.
The researchers found that whereas modern animals grow teeth by layering enamel
over dentine, and late conodonts by a similar method, early conodonts had no enamel-like
layers at all. This means that the tooth, as we know it today, had not yet evolved when
conodonts broke off from the group of animals that ultimately led to humans. Instead, the
tooth-like spurs seem to have evolved twice: once in late conodonts and once in the rest of
the vertebrates.
“While the later conodont tooth structures are absolutely indistinguishable from
modern skeletal materials, our work shows they are not the same thing,” says Donoghue.
“We now have to assume our teeth evolved from the armor of mud-slurping fish.”
Researchers studying the evolution of hard tissues are breathing a sigh of relief.
“Conodont tooth structures have always seemed problematic to me,” says paleontologist Per
Ahlberg at Uppsala University in Sweden. “We’ve been seeing all of these little hard
structures in the protective skin of early fish that look like the sorts of materials that would
naturally evolve into bone, and then we have the conodonts with hard bits that are always
only in their mouths,” he says. “The evolution of skeletons makes so much more sense
without conodonts in the picture.”
Mr Burley
Reading Comprehension: Answer the following questions based on the
readings above.
What was the major shift in the theory behind the development of teeth?
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How does this new theory relate to the concept of natural selection and fitness?
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What does this article suggest about the nature of science, or the permanence of
scientific theory?
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Human Change We Can Believe In
By Denis Réale
A recent symposium on evolution in Montreal posed to high-school students and
university professors the following question: “Do you think that humans are still evolving?”
Approximately 80% of the audience answered “no.” Indeed, there is an almost universal belief
that, with multifaceted cultures and intricate technology, humans have freed themselves from
the pressures of natural selection.
Recent findings, however, show otherwise. Far from providing immunity against
evolutionary pressures, culture often creates new ones. For example, the genes associated with
digestion of lactose are more prevalent in populations that have traditionally bred cattle and
consumed milk.
In scientific reviews in Nature Genetics and Proceedings of the National Academy of
Sciences of the United States of America, the evolutionary biologist Stephen Stearns and his
colleagues set out to demonstrate that natural selection operates on contemporary humans.
Supported by extensive genealogies, including centuries of church and national health
registries, their argument is convincing.
Indeed, contrary to the widely held assumption that evolution takes millennia to
manifest itself, recent evidence suggests that its effects can become visible as quickly as in a
Mr Burley
few generations. Rapid evolutionary change, or “contemporary evolution,” is not drastic;
humans are not likely to sprout wings a few generations down the road. Rather, these
evolutionary effects are difficult to detect, as they are reflected in a population’s genetic
composition.
Contemporary evolution requires a specific set of conditions. First, the population must
comprise individuals with varying characteristics, or traits. Moreover, members of the
population must differ in terms of survival rates, including, most important, lifetime
reproductive success (LRS) – the total number of offspring that they produce over a lifetime.
These conditions are fundamentally linked: different values for a particular trait translate into
diverse survival rates.
This crucial link facilitates change in a trait’s average value over successive generations.
For example, if larger individuals produce more children than smaller ones, the number of
larger individuals would grow, thereby increasing the average size of individuals in the
population. The most significant changes occur when individuals at one end of a trait’s value
are heavily favored, pushing the entire population in that direction.
Prevalent human traits are often strongly associated with LRS. For example, people who first
reproduce at a younger age tend to have more children, so selection generally favors those who
become parents earlier. Tall women’s LRS tends to be lower, while tall men’s is higher.
In a recent study, research psychologist Markus Jokela and his colleagues took this link
further, connecting LRS to personality. According to Jokela, selection pressure favors people of
both sexes who are extroverted, open to experience, and less anxious. Moreover, women who
are agreeable and less meticulous do better reproductively, while these qualities do not affect
men’s LRS at all. Even certain cultural traits, such as income and wealth, can be connected to
LRS: in men, the link is positive; in women, it is negative.
But translating selection pressure into evolutionary change requires another crucial
ingredient: the variation observed in the trait should be caused at least in part by genetic
differences. Indeed, evolution is possible only if the resemblance between related individuals
has a genetic basis, and is not simply a reflection of a shared environment.
For example, siblings do not have to grow up together for their resemblance to be
evolutionarily meaningful, owing to their common genes. Even when it comes to morphology,
personality, and life-history traits – such as age at sexual maturity and fertility – related
individuals’ likeness often has a genetic basis.
The conditions required for rapid evolutionary change to occur in human populations
exist. But, given that measurable alterations in a trait over time can occur for many reasons –
including those related to shared culture or environment – or randomly (“genetic drift”),
studies demonstrating this phenomenon are rare. Today’s challenge is to isolate the diverse
sources of change.
Recently developed statistical tools have finally made this possible. With more
sophisticated methods, my colleagues and I were reliably able to distinguish genetic changes,
and thus to demonstrate an evolutionary shift toward a younger age at first birth in a small,
insular population in Québec over the last 140 years.
This discovery challenges another fundamental myth: evolutionary change necessarily
benefits the species. In fact, evolution simply increases the average individual’s reproductive
success – with potentially damaging demographic consequences. So, while contemporary
evolution is occurring, adaptation may not always lead to a better life.
Mr Burley
Reading Comprehension: Answer the following questions based on the
readings above.
How is LRS related to fitness?
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What are the traits favored by selection in our current society?
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Does the explanation of modern human evolution fall in line with the theories and
principles that we have discussed? Why or why not?
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The author states, “While contemporary evolution is occurring, adaptation may not always
lead to a better life.” Explain this concept, giving at least one example of this in humans or
other organisms that makes life difficult.
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Mr Burley