Transcript MC Question

LO 1.2 : The student is able to evaluate evidence provided by data to qualitatively and
quantitatively investigate the role of natural selection in evolution.
SP 5.3: The student can evaluate the evidence provided by data sets in relation to a particular
scientific question.
Explanation: Evolution is a change in the genetic makeup of a population over time, with natural selection
as its major driving mechanism. Due to competition for limited resources, individuals with more
favorable variations or phenotypes are more likely to survive and produce more offspring, thus passing
traits to future generations. Catastrophic events, human events, and random environmental changes can
result in alteration in the gene pool of the population especially in small populations. Mutations in DNA
and recombination during meiosis are sources of variation. Human-directed processes also result in new
genes and combinations of alleles that confer new phenotypes. Mathematical approaches are used to
calculate changes in allele frequency, providing evidence for the occurrence of evolution in a population.
Fitness, the number of surviving offspring left to produce the next generation, is a measure of
evolutionary success. Individuals don’t revolve , populations evolve.
M.C. Question: Which of the following is NOT a way in which natural selection affects the
distribution of phenotypes?
A) Directional selection
B) Chance events
C) Stabilizing selection
D) Disruptive selection
Learning Log/ FRQ – Style Question: Compare and
contrast the three types of natural selection:
directional selection, stabilizing selection, and
disruptive selection. Give an example of each type.
LO 1.3: The Student is able to apply mathematical methods to data from a real or simulated population to predict what
will happen to the population in the future.
SP 2.2:
The student can apply mathematical routines to quantities that describe natural phenomena
Explanation: Scientists use mathematical methods such as Hardy-Weinberg equilibrium and chi square analyst to predetermine
the behavior of a selected population over time. The Hardy-Weinberg model lets scientists calculate allelic frequencies for a
particular gene to see if a population is evolving with respect to that particular trait. The formula to represent the allelic
frequency is P² + 2pq + q²=1 where p = the dominant (A) allele frequency and q = recessive (a) allele frequency. H-W
equilibrium is best in large populations . Chi-square is a statistical test commonly used to compare observed data with data
we would expect to obtain according to a specific hypothesis. Chi-square tests are always testing what scientists call the null
hypothesis, which states that there is no significant difference between the expected and observed result. The chi square
formula states that
x²=∑(observed – expected)² (∑=the sum of)
expected
M.C. Question: All members of an isolated village were genotyped for a particular RFLP. Of the 1000
individuals, 200 were homozygous for the presence of the restriction site, 700 were heterozygous, and 100
were homozygous for its absence. What is the frequency of the "restriction site present" allele, p?
A) 0.45
B) 0.9
C) 0.2
D) 0.55
E) None of the above
Learning log/FRQ –style Question:
(A) How can the Hardy-Weinberg principle of genetic equilibrium be used to determine whether this population is evolving?
(B) Identify a particular environmental change and describe how it might alter allelic frequencies in a population. Explain which
condition of the Hardy-Weinberg principle would not be met.
LO 1.4: The student is able to evaluate data-based evidence that describes
evolutionary changes in the genetic makeup of a population over time.
SP 5.3: The student can evaluate the evidence provided by data sets in relation to a
particular scientific question.
Explanation: Natural selection can affect a population in different ways. There is
directional, stabilizing, and disruptive selection. Directional selection is when the
population has one prominent trait that goes in one extreme of the trait. Stabilizing is
when the middle trait is chosen. Disruptive selection is when the middle trait is
selected against and the two opposite extremes are chosen. The type of selection is
often asked by looking at a graph of a population’s chosen traits.
M.C. Question: From left to right in the picture
shown, what 3 types of selection are shown?
A) stabilizing, diversifying, directional
B) directional, diversifying, stabilizing
C) diversifying, directional, stabilizing
D) directional, stabilizing, diversifying
Learning Log/FRQ-style Question: Identify and
describe each type of selection and provide an
example of each.
LO 1.5: The student is able to connect evolutionary changes in a population over time to a change in the
environment.
SP 7.1: The student can connect phenomena and models across spatial and temporal scales.
Explanation: Pressures from the environment can drive a population to change over time; in most occasions it acts as a selective mechanism.
An illustrative example is provided below. Light-colored peppered moths are better camouflaged against a pristine environment; likewise,
dark-colored peppered moths are better camouflaged against a sooty environment. Thus, as the Industrial Revolution progressed in
ninteenth-century England, the color of the moth population shifted from light to dark. The peppered moth is a solid example of how
changes in an environment can drive a population to change. The graph of the peppered moth below illustrates how the Industrial Revolution
acted as a force of natural selection and drove the original population to change.
M.C. Question: A large assemblage of land snails is subdivided into two populations (A and B) by a river that effectively isolates the
populations for an indefinitely long period. From an evolutionary standpoint, which of the following is the LEAST likely to occur in the two
populations?
A) Populations A and B will eventually differ in their ecological requirements.
B) Population A may ultimately breed at a different time of the year that population B does.
C) Population A may undergo instantaneous speculation by the doubling of its chromosome numbers (polyploidy).
D) Under laboratory conditions, cross-fertilization between members of the two populations may be successful even after a long period of
geographical separation.
E) The two populations may become morphologically very dissimilar.
Learning Log/FRQ-style Question: Suppose a population of mice live on the side of a
volcanically active mountain. The population of mice has a dominant gene for white fur,
and a recessive gene for black fur. At the moment the mice are hunted at the same
rate; what would the population look like ten months after a volcanic eruption? Why?
What kind of selection is this? Draw and label a graph depicting the two populations.
Label the original population and the population after natural selection.
LO 1.6 : The student is able to use data from mathematical models based on the Hardy-Weinberg equilibrium to analyze genetic drift and effects of selection in the
evolution of specific populations.
SP 1.4: The student can use representations and models to analyze situations or solve problems qualitatively and quantitatively.
Explanation: The Hardy-Weinberg equilibrium (p^2 + 2pq + q^2 = 1/ p + q = 1) must follow 5 guidelines; random reproduction (no preference to mates), no gene
flow (no immigration or emigration), no mutations (could modify gene pool), no natural selection (change gene pool by preferring on allele to the other), and an
extremely large population size (to throw off the possibility of genetic drift). Genetic drift occurs to small populations because they do not have a large population
to counteract the random genetic drift that happens by chance (versus natural selection), and can greatly reduces genetic variation. Also, genetic drift can cause a
species that has split from the larger population to differentiate, and if isolation occurs they could become a new species. An example of this would be Canyon
Squirrels that live in around the Grand Canyon. They look very similar, but are sexually incompatible, meaning they are two separate species. At one time they
were one in the same, but perhaps the canyon created a barrier between the original population, taking one population and dividing it in half. Then, perhaps, a
recessive gene occurred more frequently in the southern population than in the northern, and therefore was passed along to the next generation more than in
the northern population, eventually creating two separate species.
M.C. Question: Supposed in a large colony of isolated beetles, where
the allelic frequencies used to be equal a few generations ago, the
frequency of the recessive allele was now nearly double that of the
dominant allele, and the frequency is still increasing. Which of the
following is most likely true concerning the scenario stated above?
A) It follows the Hardy-Weinberg equation because the population is
large enough to counteract the climbing recessive allelic frequency.
B) Genetic drift is occurring in the population.
C) Something recently has changed in their environmental
surroundings that has caused natural selection to favor the recessive
allele over the dominant allele.
D) The beetles with the dominant allele will emigrated out of the
colony.
Learning Log/FRQ-style Question: a)Discuss the difference between
the founder effect and the bottleneck effect and b) describe how
natural selection is more “predictable” than genetic drift
LO 1.7 The student is able to justify data from mathematical models based on the Hardy-Weinberg
equilibrium to analyze genetic drift and the effects of selection in the evolution of specific populations.
SP 2.1 The student can justify the selection of a mathematical routine to solve problems.
Explanation: The Hardy Weinberg equilibrium is used to simply show that genetic drift will occur in any
population which does not meet certain criteria. To maintain equilibrium the population must be large with
random mating to have a large genetic pool, which would be more resistant to alterations through the
passing of generations. Selection for specific traits in a population, mutations during zygote formation or
mutations impacting gametes, and gene flow of traits from organisms of different populations may disrupt
equilibrium by altering the gene pool leading to genetic drift over time. The Hardy Weinberg equation, p +
q= p2 + pq + q2 = 1, is used to show the genetic drift when certain conditions are placed in a population.
M.C Question: Which of the following would not cause genetic drift in a population?
a) Immigrants from Asia coming to a town on the west coast of the US
b) Mating in a population of butterflies is dependent on the most colorful wings
c) A population squirrels is very large with several traits for tail shape
d) A drought occurs that allows only plants with water conservation techniques to survive
e) A mutation occurs in a population of rabbits which causes more padded feet for crossing snow
FRQ-Style Question: Name three
factors involved in achieving Hardy
Weinberg equilibrium and explain
how it may impact genetic drift.
Describe how these influences on
genetic drift may lead to evolution
in a population.
LO 1.8 The student is able to make predictions about the effects of genetic drift, migration and artificial selection on the genetic makeup of a population.
[SP 6.4]: The student can make claims and predictions about natural phenomena based on scientific theories and models
Explanation: Genetic drift, migration, and artificial selection are all factors that affect the ratios of alleles in the gene pools of populations. Especially in small
populations, this can alter population characteristics from generation to generation. If there is a natural disaster in a region, the population will experience the
Bottleneck Effect. The surviving population by chance may have a different allelic frequency than the pre-disaster population. The Founder Effect is another
type of genetic drift. Migration occurs where a few individuals of a population become isolated and create a new population that may have different allelic
frequencies than the original population. In such situations, the genetic makeup of the populations may become so different that they can no longer reproduce
and two separate species are produced. Artificial selection is the man-made mechanism for gene selection. It takes Darwin’s theory of natural selection and
manipulates it by selecting and breeding individuals to create a species with desired traits. It alters the genetic makeup of a population for human advantage.
Based on this information, we can make predictions about the futures of populations when natural disasters strike, factors result in the migration of a few
individuals, or humans manipulate gene pools.
M.C. Question: A scientist studying birds on two adjacent islands discovers that the Bingle Bird, which has a short and strong beak, on the Island of Seuss and the
Hephalump Bird, which has a long and narrow beak, on Winnie Island have a common ancestor, but can no longer reproduce together. Which of the following
predictions correctly explains this phenomena by using a theory that incorporates the Bottleneck Effect and the Founder Effect?
A)
A drought on the Island of Seuss caused only the birds with short and strong beaks that could open hard seeds to be able to survive on the island, while
the birds with long and narrow beaks had to find another habitat where they could feed on flowers. The extended separation of the birds led to the
development of two different species.
B)
A tsunami destroyed Winnie Island, killing many birds and forcing several of the ancestral birds to move to the Island of Seuss. By chance, the alleles for a
short and strong beak were represented more on the Island of Seuss and the alleles for a long and narrow beak were represented more on Winnie Island.
Eventually, the separated populations became too genetically different to reproduce.
C)
Winnie Island has many plants with long flowers from which it is easier to obtain nectar if a bird has a long and narrow beak. The food source on the
Island of Seuss is mostly hard seeds that are easily opened with a short and strong beak. The once homogenous population went through natural selection
to create two new populations that were better suited for the food sources.
D)
Foreign predators were introduced on the Island of Seuss and Winnie Island. The predators of the Island of Seuss preferred to eat birds with long and
narrow beaks while the predators on Winnie Island ate birds with short and strong beaks. The abundant predators caused their respective prey to become
extinct, creating a population of short and strong beaked birds on the Island of Seuss and a population of long and narrow beaks on Winnie Island.
FRQ: Darwin’s research on finches in the Galapagos Islands led to his theory of evolution and its mechanism, natural selection. Describe TWO mechanisms of
genetic drift and give an example of each.
LO 1.9 The student is able to evaluate evidence provided by data from many scientific disciplines that
support biological evolution.
SP 5.3 The student can evaluate the evidence provided by data sets in relation to a particular scientific
question.
Explanation: Homologous structures are structures that are derived from a common ancestor that may not
necessarily have the same purpose, but can be used to prove common ancestry. For instance,
the forelimbs of humans and bats are homologous structures. Although they are used differently, the
basic skeletal structure is the same and they are derived from the same embryonic origin. Their similarity in
this regard could indicate a likely evolution from a common ancestor. All vertebrate embryos follow a
common developmental path due to their common ancestry. All have a set of very similar genes (the
homeobox genes) that define their basic body plan. As they grow, the differences that will distinguish the
embryos as adults become more and more apparent. The study of this development can yield insights into
the process of evolution. A more frequently used method though, is comparing DNA sequences for
similarities between species.
M.C. Question: Analysis of forelimb anatomy of human, bats, and whales shows that humans and bats, and
whales shows that humans and bats have fairly similar skeletal structures, while whales have diverged
considerably in the shapes and proportions of their bones. However, analysis of several genes in the species
suggests that all three diverged from a common ancestor at about the same time. Which of the following is
the best explanation for these data?
a. Humans and bats evolved by natural selection, and whales evolved by
Lamarckian mechanisms?
b. Evolution of human and bat forelimbs was adaptive, but not for whales.
c. Natural selection in an aquatic environment resulted in significant changes
to whale forelimb anatomy.
d. Genes mutate more rapidly in whales than in humans or bats.
e. Whales are not properly defined as mammals.
FRQ Question: Describe the modern theory of evolution and show how it is supported by evidence from two
of the following areas: population genetics, molecular biology, and comparative anatomy and embryology.
LO 1.10: The student is able to refine evidence based on data from many scientific
disciplines that support biological evolution.
SP 5.2: The student can refine observations and measurements based on data analysis.
Explanation: Biogeography, the study of the geographical distribution of species, formed an important
part Darwin’s theory of evolution and showed that closely related species tend to be found in the same
geographic region. Fossil records may show evolutionary transitions in the structure of organisms but
more importantly provide support in comparative anatomy. Homologous structures, such as the
forelimb components in many mammals are similar structures with different functions showing signs
of evolution from a common ancestor( they can also be vestigial structures). Comparative embryology
demonstrates that organisms that share close ancestors have similar modes or stages of development
and in turn show anatomical similarities between organisms. Molecular biology can also provide
evidence for biological evolution with comparisons between DNA sequences of different organisms,
and the similarities and differences between genes and proteins in each.
MC Question: All of the following pairs of structures are homologous structures except
which?
A) The wings of a bat and the wings of a butterfly
B) The arm of a human and the leg of panther
C) The hooves of a camel and the hooves of a sheep
D) The scales on the foot of a chicken and the scales on a lizard
Learning Log/ Free Response Question:
A paleontologist on an expedition in Hong Kong finds
the remains and fossils of an extinct species of city
dwelling rodent. The scientist expects to find
organisms of common ancestry in an area close to New
York City. Explain why the scientists prediction is
either valid or invalid and describe the scientific
evidence that supports your reasoning.
LO 1.11: The student is able to design a plan to answer scientific questions regarding how
organisms have changed over time using information from morphology, biochemistry, and geology
SP 4.2: The student can design a plan for collecting data to answer a particular scientific question.
Explanation: The evolution of species is a subject that is still being researched by scientists. Such a vast amount evidence
has been discovered over the past century that the theory that all life evolved from a common ancestor is now accepted by
most. This includes transitional species (such as amphibians), homologous structures between seemingly unrelated species,
similar genetic composition of species (such as humans and apes), and the geological composition of the earth
(sedimentary rocks and fossils). Studies use these bits of evidence to depict the changes animals have experienced as well
as the similarities they share.
M.C. Question: Which of the following is not a scientific
argument for the theory evolution.
A) Chimpanzees and Humans share 98% of their DNA.
B) Fossils of species with both lungs and gills have been found
in Nunavut.
C) Africans and Asians have similar physical features.
D) Species in different parts of the globe with similar
environments share many behaviours/ physical features.
Learning Log/FRQ-style Question: How can
homologus structures and biochemistry be used to
explain the changes of organisms over time? Use
specific examples.
Divergent evolution/
homologous structures
The evolution of
organisms
LO 1.12 The student is able to connect scientific evidence from many scientific disciplines to support the modern concept of
evolution.
SP 7.1: The student can connect phenomena and models across spatial and temporal scales.
Explanation: For example, DNA sequences, metabolic processes and morphological structures that arise through
evolutions connect the organisms that compose the tree of life, and the student should be able to use various types
of phylogenetic trees/cladograms to show connections and ancestry, and to describe how natural selection
explains biodiversity. To elaborate on the examples given; through research of DNA sequences species that have
similar next to identical percentage match of DNA sequences are closely related to each other. An example of,
homologous structures would be the difference between homologous bone structures and analogous bone
structures. Homologous bones look different but are structurally the same and analogous bones look the same but
are structurally different. Finally, a metabolic process that occurs in all living things on earth is respiration, which
is essential to live and life sustainment.
M.C Question: If Darwin had been aware of genes, and of their typical mode of transmission to subsequent
generations, with which statement would most likely have been in agreement?
A)
Somehow if natural selection can change one gene’s frequency in a population over the course of generations
then, given enough time and enough genes, natural selection may cause sufficient genetic change to produce new
species from old ones
B)
If an individual somatic cell genes change during its entire lifetime, supposedly making it more fit, then it will be
able to pass these genes on to its offspring.
C)
If an individual’s acquires new genes by engulfing, or somehow being infected by, another organism, then a new
genetic species will possibly be the result.
D)
A single mutant gene in a single gamete will, if perpetuated, will produce a new species within just two
generations.
Learning Log/FRQ-style Question:
Of all mutations that occur, why do only a small fraction become widespread in a gene pool?
LO 1.13: The student is able to construct and/or justify mathematical models, diagrams or simulations that represent processes of
biological evolution.
SP 1.1, 2.1: The student can use representations and models to communicate scientific phenomena and solve scientific problems
and the student can use mathematics appropriately.
Explanation: The Hardy-Weinberg Theorem can be used to describe non-evolving populations and can help find when a population
is in equilibrium. This theorem also lays the groundwork for understanding long-term evolutionary changes. All alleles and genotypes
will remain constant unless acted on by agents other than sexual recombination. In order to determine if the population is evolving,
use the following equation:
p+q= 1
p = dominant alleles
q = recessive alleles
1 = all alleles in the gene pool
It is also possible to determine specific genotypes of an individual in the population with the following equation:
(p + q)(p + q) = 1, or p² + 2pq + q²= 1
p² = AA (homozygous dominant)
q ² = aa
(homozygous recessive
pq = Aa
(heterozygous)
M.C. Question: There are 100 students in a class. Ninety-six did well in the course whereas four blew it totally and received a grade of
F. In the highly unlikely event that these traits are genetic rather than environmental, if these traits involve dominant and recessive
alleles, and if the four (4%) represent the frequency of the homozygous recessive condition, calculate the frequency of the recessive
allele.
a.) 40%
c.) 20%
b.) 4%
d.) 2%
Learning Log/FRQ-style Question: A large population of Biology teachers have 396
red-sided individuals and 557 tan-sided individuals. Red is completely recessive. Calculate
the following:
a.) The allele frequencies of each allele.
b.) The expected genotype frequencies.
c.) The number of heterozygous individuals you would predict.
d.) The expected phenotype frequencies.
•
LO 1.14 The student is able to pose scientific questions that correctly identify
Explanation: Following theessential
success of properties of shared, core life processes that provide insights into the
the Miller Urey experiment, science
history of life on Earth.
determined that organic compounds
SP 3.1 The student can pose scientific questions.
including amino acids similar to those
found in modern organisms were
likely generated during the volatile
conditions of early Earth. Similar
discoveries have been made relating
to the creation of macromolecules
from the dripping of amino acid
solutions onto sand and rocks.
Protobionts, membrane bound
predecessors to modern life on Earth
are theorized to be the membranebound results of abiotic production
of organic molecules and may hold
answers to the origins of life.
Evidence of a common ancestor of all
modern life persists in the form of
many contemporary biological
processes and structures, such as
ribosomes, RNA, and the electron
transport chain. Even less common
aspects of life such as the
mitochondria and chloroplasts in
many eukaryotes suggest common
ancestry as well as hint at the
possibility of the origin of eukaryotes
from the process of endosymbiosis.
By observing parallels between
distinct life forms, it is possible to
generate a better understanding of
the history of life on Earth and ask
informed, scientific questions about
it.
M.C. Question: Which of the following
characteristics is not exclusive to eukaryotic
life?
A) cell wall composed of either chitin or cellulose
B) flagella or other external structures used in
locomotion
C) cytoskeleton of microtubules, microfilaments,
and/or intermediate filaments
D) presence of the Golgi apparatus
E) genetic material wrapped into chromosomes
Learning Log/FRQ-style Question: Among the
varied forms of life on earth, many organisms
share common life processes despite other
enormous functional and taxonomical
differences.
Identify and describe three processes shared
across multiple kingdoms and list at least two
of the taxonomical kingdoms that share them.
LO 1.15: The student is able to describe specific examples of conserved core biological processes and features shared by
all domains or within one domain of life, and how these shared, conserved core processes and features support the
concept of common ancestry for all organisms.
SP 7.2: The student can connect concepts in and across domain(s) to generalize or extrapolate in and/or across enduring
understandings and/or big ideas.
Explanation: Despite the incredible amount of diversity between the species inhabiting the earth, there is a number of traits
which are shared by all species in a given domain or all domains. These traits are typically expressed at the cellular level,
and as a rule have remained generally unchanged throughout evolution. Biologists often use these conserved core
processes and features to determine how and when different domains of life diverged from one another, and provide
evidence for a common ancestor shared by all species. For example, since every known species alive today features
metabolic pathways, biologists can reasonably theorize that the first species to develop metabolic pathways lived long ago,
and all currently living species diverged from that one at some point.
MC Question: Based on your knowledge of membrane bound organelles, which of the following
statements is true?
A) Plants are more closely related to protists than fungi
B) Bacteria developed before protists
C) The earliest cells were eukaryotic
D) Animals were the last kingdom to evolve
Free Response Question: You are an evolutionary
biologist comparing the genetic codes of a species
of animal and a species of plant. Using conserved
core biological processes or features in your answer,
explain why the two species’ genetic codes are so
similar.
LO 1.16: The student is able to justify the scientific claim that organisms share many conserved
core processes and features that evolved and are widely distributed among organisms today.
SP 7.1: The student can justify claims with evidence.
Explanation: Conserved core processes are adaptations that are genetically beneficial or necessary for
survival. They are then passed down from then on to their offspring. This is evidence that all organisms
are linked by the lines of descent from common ancestry. Examples include DNA and RNA,
cytoskeleton, a nucleus, membrane-bound organelles, linear chromosomes, and endomembrane systems.
The existence of these properties in organisms today implies that they were present in a universal
ancestor and that present life evolved from a universal ancestor. Phylogenetic trees and cladograms
can represent acquired and lost traits in the course of evolution. For example in the picture, the
characteristic of jaws is present from sharks onward, however they do not have lungs.
M.C. Question: Which of the following would be most useful for
constructing a phylogenetic tree for several fish species?
A. Several analogous characteristics shared by all the species
B. A single homologous characteristic shared by all the fishes
C. The total degree of morphological similarity among various
fish species
D. Several characteristics thought to have evolved after
different fishes diverged from one another
E. A single characteristic that is different in all the fishes
Learning Log/FRQ-style Question: Darwin is considered the “father of evolutionary biology.” One of his
contributions to the field of evolutionary biology is branching evolution, which implies the common
descent of all species. Discuss one example of supporting evidence.
LO 1.17: The student is able to pose scientific questions about a group of organisms whose relatedness is described by a
phylogenetic tree or cladogram in order to (1) identify shared characteristics, (2) make inferences about the evolutionary
history of the group, and (3) identify character data that could extend or improve the phylogenetic tree.
SP 3.1: The student can pose scientific questions.
Explanation: Phylogenic trees and cladograms are used as graphical representations of evolutionary history and can be
tested. Each can represent traits that are either derived or lost due to evolution. They illustrate speciation that has
occurred, in that relatedness of any two groups on the tree is shown by how recently two groups had a common ancestor.
They make it possible to determine how species over millions of years are related. Phylogenetic trees and cladograms can
be constructed from morphological similarities of living or fossil species or from DNA and protein sequence similarities by
using sophisticated computer programs. Phylogenetic trees and cladograms are constantly being revised based on the
biological data used, new mathematical and computational ideas, and current and emerging knowledge.
M.C. Question: What can be inferred from a species that is on a clade above a specific characteristic?
A) The species does not possess this characteristic.
B) The characteristic was lost through natural selection and no longer possessed by the species.
C) The species has evolved so that it possesses that characteristic.
D) An ancestor of the species possessed this characteristic.
Learning Log/FRQ-Style Question: A group of scientists predict
that two types of birds evolved from one common ancestor.
One species of bird was found in Alaska while the other was
discovered in the northeast region of Russia. What visual
diagram could be used to display the relationship between
the two species in relation to their ancestor? The two birds look
almost identical, but one type on bird can fly while the other
cannot, and when face postzygotic barriers when scientists
attempt to mate them together. Between which two
classification groups does this suggest divergence occurred?
LO 1.18: The student is able to evaluate evidence provided by the data set in conjunction with a
phylogenetic tree in a simple cladogram to determine evolutionary history and speciation.
SP 5.3: The student can evaluate the evidence provided by data sets in relation to a particular
scientific question.
Explanation: A phylogenetic tree is a branching diagram that represents a hypothesis about evolutionary
relationships between organisms. The use of the phylogenetic trees is useful when trying to determine when
and where in the organisms history speciation occurred. In a phylogenetic tree the main branch is the class of
the organism; this is the broadest phylogenetic trees will get. They then move into the order of the organism.
From there it gets more specific into family, genus and species. The hierarchical classification is reflected in the
progressively finer branching of the phylogenetic trees. Evolutionary history can be explained by the branching
that occurs. For every branch on the phylogenetic tree, there is a case of speciation and evolution. Also, the
number and length of the branches reflect the number of changes that have taken place in a specific DNA
sequence in the organisms history. This helps further prove evolution by phylogenetic trees.
M.C. Question: The underlying principles of cladograms and phylogenetic trees
are that
A. Taxa that share more that one homologous trait are generally more closely
related than species that share few.
B. The more recently that taxa have branched from a common ancestor the
less similar should they be in morphology and in their DNA sequences
C. Taxa that share many derived traits are likely to be most closely related.
D. A and C only
Learning Log/FRQ-style question:
How do phylogenetic trees prove evolution? What do more branches mean? Less?
LO 1.19- The student is able create a phylogenetic tree or simple cladogram that correctly represents evolutionary history and
speciation from a provided data set.
SP 1.1- The student can create representations and models of natural or phenomena and systems in the domain.
Explanation: A phylogenetic tree is branching diagram that expresses inferred evolutionary relationships. The branching of these
trees reflects the hierarchical classification of certain groups involved in more inclusive groups. A phylogenetic tree is
constructed from two way branch points or more; each branch point represents the contrast of two species from a common
ancestor. Each of the deeper branch points portray continuously greater amounts of divergence. Shared characteristics due to a
common ancestor is represented by a diagram called a Cladogram. A cladogram forms the basis of a phylogenetic tree. Within
the tree, a clade is expressed as a group of species that includes an ancestral species and all of its descendants. Cladistic is how
species are grouped into clades.
M.C. Question: Which of the following would be a
constructive reason for creating a phylogenetic tree for
leopards?
A) Several analogous characteristics shared with
similar animals
B) A single characteristic is shared with several
animals
C)Several characteristics predicted to have evolved
from other species over the years
D) A single characteristic shared with all leopards.
Learning Log/FRQ Question: Hierarchical classification is
reflected in the continuous branching of phylogenetic
trees. Species that appear to be closely related are put
in the same group. Name two ways to trace phylogeny.
Draw and label THREE of the hierarchical
classifications in the correct order.
LO 1.20: The student is able to analyze data related to questions of speciation and
extinction throughout the Earth’s history.
SP 5.1: The student can analyze data to identify patterns or relationships.
Explanation: Speciation is the divergence of one species into two distinct species that cannot produce fertile
offspring. Speciation may be a result of geographic isolation (allopatric) or intrinsic factors (sexual selection,
chromosomal changes) among a population in one area (sympatric). Mutations are the basis of all
speciation, which can be illustrated graphically by cladograms or by an evolving percentage of similarity in
their nucleotide sequences (think BLAST). Speciation can occur in bursts followed by quiet periods
(punctuated equilibrium) or instead be slow (gradualism). Extinction can occur in the same manner, and can
often be rapid during times of ecological stress (such as a giant meteor for the dinosaurs). There have been
five major extinctions in the history of Earth, most caused by extreme habitat change. Extinction may be
caused by climate change, overharvesting, disease, or invasive species.
1930's
1920's
1910's
1900's
1890's
1880's
1870's
M.C. Question: Which situation below would ENCOURAGE speciation?
Dingo & Thylacine Pop. 1870-1940
A) A large population of animals.
B) Population exhibits zero net mutation.
600000
C) Animals mate randomly.
500000
D) A small population of animals.
400000
FRQ: To the left is a hypothetical graph following
300000
the populations of dingoes and thylacines (a striped
200000
wolf much like the dingo) on the Australian
100000
mainland. Given what you know about extinction,
give TWO reasons why the thylacine might have gone
0
extinct. Also give TWO reasons why, over 4,000 years, the
dingo and thylacine might have become two different species
descendant from wild dogs while together on mainland
Australia.
Dingo
Thylacine
LO 1.21: The student is able to design a plan for collecting data to investigate the scientific claim that
speciation and extinction have occurred throughout the Earth’s history
SP 4.2: The student can design a plan for collecting data to answer a particular scientific question.
Explanation: Data collected throughout the years have shed light to the changes which have happened upon Earth
before our existence. Speciation aids in theories of a common origin by adding up with other evidence such as
biogeography and embryology/comparative anatomy. Almost like puzzle pieces, with each new discovery the big
picture becomes more coherent of what the past was like for species and what the future might hold, as well as
make the theory itself stronger. However extinction is the reality of what will be missing from our ecosystems if
species are continuously lost and not properly taken care of.
M.C. Question: What is a leading cause of extinction among species?
A) Competition
B) Natural Selection
C) Habitat loss
D) Increasing disease
Learning Log/FRQ-styled Question:
One of Darwin’s key pieces of evidence in proving his
theory of evolution was fossils. Compare and
contrast modern evidence of speciation with the
fundamental observation of fossils. Why were
fossils originally so significant in comparison to
other types of evidence and why do they still
hold merit?
LO 1.22: The student is able to use data from a real or simulated population(s), based on graphs or models
of types of selection, to predict what will happen to the population in the future.
SP 6.4: The student can make claims and predictions about natural phenomena based on scientific
theories and models.
Explanation: In populations, there are three different types of natural selection: directional selection, stabilizing selection,
disruptive selection. Graphs and models of these types of natural selection allow people to predict what is most likely to
happen, within that population in the near future. Natural selection is when organisms are able to better adapt to their
environment to help them survive and produce better adapted offspring. Each type of natural selection has different, and
distinct characteristics. Directional selection is when a population’s trait distribution shifts to another extreme. Stabilizing
selection is when the extreme traits of a population are selected against, stabilizing trait distribution, narrower graph.
Disruptive selection is when the population favors the two extremes, mostly homozygous dominant or recessive, few
heterozygotes.
M.C. Question: A orange tiger is heterozygous for the white fur and orange fur gene, it mates with another
tiger with the exact same genotype in the snowy mountains of Nepal. After multiple matings between tigers
of the same genotype occur in the same area, the majority of offspring seem to be white. This is due to an
adaptation for camouflage purposes, what kind of natural selection is this?
A) Stabilizing selection
B) Directional selection
C) Disruptive selection
D) Super selection
Learning log/FRQ-Style Question
For each type of natural selection listed in the
explanation, create a graph, list an example, and define
the type of natural selection.
A. LO 1.23 The student is able to justify the selection of data that address questions related to
reproductive isolation and speciation.
B. SP 4.1 The student can justify the selection of the kind of data needed to a answer a particular
scientific question.
C. Reproductive isolation refers to the inability of a species to breed successfully with other related
species due to geographical, behavioral, physiological or barriers. An example of this is when a
mountain range causes a species to become separated, the mountains would cause some of the specie
to be adapted to a cold climate and some to a warm. Even though the animals come from the same
specie they would not mate because they have adapted to their separate climates. Speciation is the
evolutionary formation of new biological species, usually by the division of a single species into two
or more genetically distinct ones. Darwin’s finches are a perfect example of speciation. Genetically
the finches changed over a period of time to adapt to the environment of the island.
D. Which of the following does not tend to promote speciation?
A) founder effect
B) reproductive isolation
C) natural selection
D) gene flow
E. Describe a method of speciation that can lead to the development of separate species from one common
specie? Give an example.
L.O. 1.24 The student is able to describe speciation in an isolated population and connect it to change in gene frequency,
change in environment, natural selection and/or genetic drift.
SP 7.2 The student can connect concepts in and across domains to generalize or extrapolate in and/or across enduring
understandings and/or big ideas.
Explanation: Speciation is the origin of new species as they diverge from a single common ancestor. There are two patterns
to speciation: anagenesis and cladogenesis. Anagenesis is a single species obtaining hertiable traits over time and
eventuallty becoming a different species, separate from its ancestors. Cladogensis is the result of branching evolution,
where a new species arises from a separate population. Allopatric speciation, for example, occurs when one species is
separated by a large barrier, like the grand canyon separating a single species of squirrel. Over time the single species has to
adapt to two different environments, resulting in two new species. Genetic drift explains how allele frequencies fluctuate
unpredictably from one generation to the next. Genetic drift occurs when a population is greatly decreased from its original
size and then new population, as it repopulates, does not represent the original population. Natural selection occurs as
animals that are les fit for the environment are killed or die off. The surviving population is typically more fit to survive in
that location.
M.C. Question: More epic and manly manes on lions have evolved to be so
magnificent due to the fact that lady-lions love the scruffy, neck-scarf mane. The
process by which these lion’s manes have evolved is best described as
A. Genetic drift that changes the frequencies of the alleles for mane manliness
B. Natural selection for sexual reproduction that maintains variations in the genes
that influence sexy manes.
C. Intersexual selection for traits, such as long flowing manes, that help males
attract mates.
D. Intrasexual selection for traits, such as long flowing manes, that help males win
contests for access to females.
E. Directional selection for traits, such as long flowing manes, that improve males’
ability catch food and stun onlookers.
Free Response: Suppose a population of 1000 unicorns experience a bottle neck
where 50% of the population is wiped out. The original population was 55% red,
35% pink and 10% white; homo. Dominant, heterozygous, and homo. Recessive,
respectively. What would likely be the most common phenotype? Least
common? Why? What would likely happen to the white unicorn phenotype?
LO 1.25 Answer Slide
LO 1.26: The student is able to evaluate given data sets that illustrate evolution as an ongoing process.
SP 5.3: The student can evaluate the evidence provided by data sets in relation to a particular scientific question.
Explanation: We learned that scientific evidence supports the idea that evolution, or the process by which living organisms are
thought to have developed, has occurred in all species and that it continues to occur with a few examples including: Chemical
resistance (mutations for resistance to antibiotics, etc.), emergent diseases, observed directional phenotypic change in a
population (Grants’ observations of Darwin’s finches in the Galapagos), and eukaryotic examples that describe evolution of a
structure as a process such as heart chambers, limbs, the brain, and the immune system. On the AP exam, you will be responsible
for being able to draw conclusions from a given data set having to do with subjects such as those stated above. A good example of
a data set set question is one that would ask you to either compare or contrast DNA genomes among several species, similar to
what we did in the BLAST lab earlier this year.
Multiple Choice:
Analysis of forelimb anatomy of humans, bats, and whales shows that humans and bats have fairly similar skeletal structures,
while whales have diverged considerably in the shapes and proportions of their bones. However, analysis of several genes in these
species suggests that all three diverged from and common ancestor at about the same time. Which of the following is the best
explanation of these data?
a. Humans and bats evolved by natural selection, and whales evolved by Lamarckian mechanisms.
b. Evolution of human and bat forelimbs was adaptive, but not for whales.
c. Natural selection in an aquatic environment resulted in significant changes to whale forelimb anatomy.
d. Genes mutate more rapidly than in humans or bats.
e. Whales are not properly defined as mammals.
Free Response: Using your knowledge
of evolution, describe how the following
concepts relate to Darwin’s theory of
evolution by natural selection:
•Over reproduction of populations
•Limited resources
•Heritable variation
LO 1.27: The student is able to describe a scientific hypothesis about the origin of life on Earth.
SP 1.2: The student can describe representations and models of natural or man-made phenomena and
systems in the domain.
Explanation: The primitive Earth provided inorganic material that could have been synthesized into organic
molecules like lipids, nucleic acid, and carbohydrates using the available free energy, like lightning. These
molecules could have served as building blocks for complex molecules such as nucleotides or amino acids.
The joining of such monomers to make polymers could have had the ability to replicate and store data, and
eventually begin to work together to make the earliest and simplest form of cells. Miller and Urey simulated
the early Earth in a closed system experiment that consisted of hydrogen, methane, ammonia, and water
vapor. Over a very long time, the experiment eventually formed organic molecules, supporting the
hypothesis.
M.C. Question: The most compelling evidence that RNA evolved before
DNA is…
A) RNA is copied by ribozymes, which evolved before DNA
Polymerase.
B) RNA’s single stranded coding allows it to assume different shapes
to interact and adapt better.
C) DNA was too complex for such primitive cells.
D) RNA uses nucleotides that evolved before those in DNA.
Learning Log/FRQ-style Question: Using the picture to the right,
explain why Miller and Urey might have used certain features in their
experiment and what they represent in Earth as it was billions of years ago.
(ex: Miller and Urey included electrodes because….)
LO 1.28: LO 1.28 The student is able to evaluate scientific questions based on hypotheses about the origin
of life on Earth.
SP 3.3: The student can evaluate scientific questions.
Explanation: There are a variety of hypothesis regarding the origin of life on earth. One widely accepted
explanation is that the earth began with inorganic particles. These particles, with the help of high heat from
lightning bolts and UV rays, over time became organic molecules. In turn, these molecules were combined to
make polymers such as amino acids and nucleotides. This complicated reaction could have occurred in
solution (organic soup model) or solid reactive surfaces. The Miller Urey experiment showed that organic
compounds such as amino acids, which are essential to cellular life, could be made easily in an environment
similar to primitive earth’s conditions.
M.C. Question: Scientists agree that the first
molecules on earth were:
A) Proteins
B) Nucleic acids
C) RNA
D) None of the above
Learning Log/FRQ-style Question:
Explain the Primordial (Organic) Soup
theory. Does this process involve
reduction or oxidation, and why?
LO 1.29: The student is able to describe the reasons for revisions of scientific hypotheses of the
origin of life on Earth.
SP 6.3: The student can articulate the reasons that scientific explanations and theories are
refined or replaced.
Explanation: A hypothesis is a starting point for investigating a question or a problem. In order to reach a
truthful conclusion, the hypothesis must be valid at the end of the experiment. If any part of the
experiment proves false, then the hypothesis must be revised to reach a successful conclusion. Since
human history did not start at the birth of the earth, scientists have had to guess and investigate the
building blocks of life on earth. They do this by hypothesizing, performing an experiment, and then rehypothesizing.
M.C. Question: Miller and Urey created and performed
an experiment using the Primordial Soup theory. Their
experiment proved that this theory was a possibility for
the origin of life. According to their experiment, which
statement is false?
A) Life could start through chemical reactions
B) Organic compounds are capable of being made
through extreme conditions
C) Used known gases on primitive earth
D) It was done using a closed environment like primitive
earth
Learning Log/FRQ-style Question: Compare and
contrast the early Earth vs. Earth today, be specific
about the environment and conditions that
existed.
LO 1.30: The student is able to evaluate scientific hypotheses about the origin of life on Earth.
SP 6.5: The student can evaluate alternative scientific explanations.
Explanation: There were four main stages of Early Earth making the origin of life possible. These included the abiotic
synthesis of small organic molecules, the joining of small molecules into polymers including proteins and nucleic acids,
packaging of molecules into protobionts with membranes and the ability to maintain internal chemistry, and self-replicating
molecules that eventually made inheritance possible. It is likely the first atmosphere was thick with water vapor and various
compounds released by volcanic eruptions. This included high levels of nitrogen, CO2, methane, ammonia, hydrogen, and
hydrogen sulfide. Earth also had storms that cooled the Earth and produced lightening that may have sparked life on Earth.
Miller-Urey experiment mimics the conditions of early earth and as a result found the product were organic molecules
necessary for life. Researchers also argue polymers formed spontaneously without the help of enzymes or ribosomes. This
claim was supported when scientists dripped amino acids onto hot sand, clay, or rock. The other portion of early life are
protobionts. Protobionts produced molecules surrounded by membrane or membrane like structure. It has simple
reproduction, metabolism, and is able to maintain internal chemical environment different from that of its surroundings.
Protobionts best suited to their environment could reproduce and create other protobionts best suited to the environment. The
first genetic material to form is predicted to be RNA. Structurally, RNA is simpler than DNA and is able to assume a variety
of 3D shapes mandated by nucleotide sequences. Collections of RNA moecules best suited for the environment continued to
be reproduced and gave way to natural selection of protobionts.
Multiple Choice: RNA is most likely the first genetic material on Earth
because __________.
A.RNA is structurally simpler than DNA.
B.RNA has simpler reproduction.
C.RNA is able to assume a variety of 3D shapes mandated by nucleotide
sequences.
D.All of the above.
Free Response: Discuss the elements and conditions of early Earth and how the combination contributes to the creation of
early life. Describe the most widely accepted theory for the early evolution of life. Remember to discuss protbionts, genetic
materials, and scientific experiments in the explanation.
LO 1.32: The student is able to justify the selection of geological, physical, and
chemical data that reveal early Earth conditions
SP 4.1: The student can justify the selection of the kind of data needed to answer a particular scientific question.
Explanation: The Earth formed approximately 4.6 billion years ago (bya), and the environment was too hostile for life until 3.9 bya, while
the earliest fossil evidence for life dates to 3.5 bya. Taken together, this evidence provides a plausible range of dates when the origin of
life could have occurred. Chemical experiments have shown that it is possible to form complex organic molecules from inorganic
molecules in the absence of life. An example would be the Miller-Urey experiment. Miller took molecules which were believed to
represent the major components of the early Earth's atmosphere and put them into a closed system . The gases they used were
methane (CH4), ammonia (NH3), hydrogen (H2), and water (H2O). Next, he ran a continuous electric current through the system, to
simulate lightning storms believed to be common on the early earth. Analysis of the experiment showed that as much as 10-15% of the
carbon was now in the form of organic compounds. Two percent of the carbon had formed some of the amino acids which are used to
make proteins.
MC Question:
Which of the following is the likely source of energy for the synthesis of
the small organic molecules that presumably predated the first forms
of life on Earth?
A.) Fermentation by bacteria
B.)Photosynthesis by microscopic algae
C.) Lightning from constant storms
D.) Shifts in ocean currents
Learning Log/FRQ Style Question:
Some scientists believe that in order for ecosystems to maintain a
balanced or steady state, biodiversity must be conserved. Using both
classical Darwinian thought and the modern synthesis of evolutionary
theory, answer the following question as it relates to biodiversity.
Insects are the most diverse group of organisms on Earth. Give some
possible explanations for why this diversity exists.