Transcript evolution 2017 - week 3 britx

Monday – 2/6
• Grab your binder as you come in.
• Answer the Monday question under genetics
warm ups on the paper you picked up when
you walked in
Monday – 2/6
1. A squash plant that is homozygous for white
fruit is crossed with a plant homozygous for
yellow fruit. All white fruits are produced. If
these white fruit offspring are crossed with each
other, what is the probability of offspring
producing white fruit?
a. 75%
b. 100%
c. 25%
d. 50%
Evidence for Evolution
• We will be taking notes and answering
questions as we work through the various
types of evidence for evolution.
• Be sure to follow along in your notes packet.
Section 6: Evidence of Evolution
Evidence supporting Darwin’s theory has
come from many sources:
• Fossil Record
• Homologous Structures
(Comparative anatomy
of organisms)
• Developmental
Patterns
• Biogeography
(Distribution)
• Similarity of DNA
• Adaptations
Section 6: Fossil Record
The fossil record shows a
successional appearance and
disappearance of species.
Section 6: Fossils
Section 6: Fossils
Section 6: Fossils
Use the image of the fossil record to answer
the following questions.
1. Which organism is the oldest?
2. Which organism most recently evolved?
3. List the organisms that are only found in one
layer of strata (rock).
Section 6: Fossils
Use the image of the fossil record to answer
the following questions.
1. Which organism is the oldest?
Trilobite
1. Which organism most recently evolved?
Fern
1. List the organisms that are only found in one
layer of strata (rock).
Trilobite and Ammonite
Section 7: Comparative Anatomy
Homologous Structures = Same structure,
different function.
Usually indicates common ancestry (divergent).
Example:
Wing, arm, and fin
Homo = Same
These organisms
probably came from
the same ancestor
(these are all mammals in the example)
Section 7: Comparative Anatomy
Analogous Structures = different structure,
same function.
Usually indicates they evolved separately, but
in similar environments (convergent).
Example:
Bird Wing
Butterfly Wing
Bat Wing
The wings are all used for flight, but the
organisms are not related – bird, insect,
mammal.
Section 7: Comparative Anatomy
Vestigial Structures = structures without function
They are remnants of evolutionary past
Example:
Whales have a
pelvis, but they
no longer walk
on land.
Do humans have vestigial structures? Sure!
Structural: appendix, tailbone, wisdom teeth
Behavioral (goose bumps and palmar grasp reflex),
Sensory (decreased olfaction)
Molecular (junk DNA).
Section 7: Comparative Anatomy
Section 7: Comparative Anatomy
Section 7: Comparative Anatomy
Section 7: Comparative Anatomy
Section 7: Comparative Anatomy
Section 7: Comparative Anatomy
Section 7: Comparative Anatomy
Monday Exit Ticket
1. Scientists estimate that there are more than 20,000 species of ants.
The species range in size from 1 mm long to 38 mm long and live in most
environments. The diets of ants range from flowers and seeds to fluids
from their own larvae. Ants have been able to successfully inhabit so
many different environments because their populations have been able
to —
a.
b.
c.
d.
hybridize with other species of insects
adapt to a variety of habitats and food sources
fill niches usually occupied by mammals
occupy habitats that have no other life-forms
Tuesday 2/7
Tuesday 2/7
2. In cocker spaniels the allele for a black coat color
(B) is dominant over the allele for brown coat color
(b). If a brown cocker spaniel is crossed with a
heterozygous black cocker spaniel, which of the
following genotypic ratios can be expected?
a.1 BB: 2 Bb: 1 bb
b. 2 BB: 0 Bb: 2 bb
c. 2 BB: 1 Bb: 0 bb
d.0 BB: 2 Bb: 2 bb
Tuesday 2/7
3. In guinea pigs, the allele for a rough coat (R) is
co-dominant with the allele for a smooth coat (S).
Whereas some guinea pigs have coats with both
smooth and rough hairs (RS). A guinea pig with a
rough coat is mated with a guinea pig with a
smooth coat. What is the probability that their
offspring will have a smooth coat?
a. 0%
b. 25%
c. 50%
d. 75%
Section 8: Embryology
(Developmental Patterns)
• Embryos are similar when they are developing
• It is hard to notice the difference between a
chicken embryo and a human embryo in the early
stages.
• At one point, human embryos develop a coating
of fur!
Embryo Image Link
Section 8: Embryology
Section 8: Embryology
Section 8: Embryology
Section 9: Biogeography
Similar environments on the different continents have
produced similar adaptations in unrelated species.
Similar ecological opportunities on different continents have resulted
in convergent evolution among these and other mammals. Mammals
that feed on ants and termites evolved not once but five times in
different regions. Powerful front claws; a long, hairless snout; and a
tongue covered with sticky saliva are common adaptations in these
insect-eating animals.
Section 10: Molecular Biology
Closely related species will have more
similarities in their DNA and genes.
Station 10: Molecular Biology
Station 10: Molecular Biology
Review Packet
• Use the remainder of the class to begin your
review.
• Raise your hand if you have a question.
• Make sure you bring your review and your
notes home with you over the weekend to
study.
• Your test in on Tuesday!!!
Tuesday Exit Ticket
2. In cats, the bones in the legs involved in
walking are very similar to the bones of whales'
flippers that are involved in swimming. These
are examples of —
a. analogous structures
b.homologous structures
c. vestigial structures
d.endosymbiosis
Tuesday Exit Ticket
3. Global temperatures tend to change on a regular basis.
The availability of environmental resources such as water
and food tend to fluctuate on a regular basis as well.
Individuals who are better able to cope with such
challenges in their environment tend to –
a. decrease in population over time
b. leave more offspring than those more suited to the
environment
c. leave fewer offspring than those less suited to the
environment
d. leave more offspring than those less suited to the
environment
Wednesday – 2/8
• Grab your binder as you come in.
• Answer the following question on your
whiteboard.
Wednesday – 2/8
4. An experiment isolated two genetic traits in mice:
fur color and tail length. Black fur (B) is dominant over
tan fur (b), and short tails (S) are dominant over long
tails (s). Cross two heterozygous black, heterozygous
short-tailed mice. Of the 16 possible offspring
produced, how many are mice that are black with long
tails?
a. 1
b. 2
c. 3
d. 4
Wednesday – 2/8
5. In cattle, the allele for short horns
(S) is incompletely dominant over the allele for long
horns (L). Cattle that have medium length horns
are heterozygous (SL). Two heterozygous mediumhorn cattle are bred and produced four offspring.
What percentage would you expect to have long
horns?
a. 75%
b. 50%
c. 25%
d. 100%
For the following situations, identify if the
situation reflects the Founders Effect or
Bottleneck.
In the 1700s, a small group of Europeans settled in
eastern Pennsylvania. Among this small group was an
individual who carried an allele for Ellis-van Creveld
syndrome. Ellis-van Creveld syndrome is a very rare form
of dwarfism causing short stature, extra fingers
(polydactyly), abnormal teeth and nails, and heart
defects. The allele for Ellis-van Creveld syndrome is found
at a frequency of 7% in the Pennsylvania Amish in
comparison to only 0.1% in the general population. The
low allelic frequency of 0.1% was also the allelic
frequency of the original European population from
which the Amish migrated.
While the Amish live in close proximity to large, diverse
human populations that would be capable of breeding,
the culture of the Amish restricts marriage outside of the
group. This results in genetic isolation and group
interbreeding that allows the frequency of the allele for
Ellis-van Creveld syndrome to not only persist but
increase over time.
Answer: Founders Effect
Northern elephant seals were hunted in the 1890s.
Hunting reduced their population size to as few as
20 individuals at the end of the 19th century. Their
population has since rebounded to over 30,000—
but their genes still carry the marks of this
incidence. They have much less genetic variation
than a population of southern elephant seals that
was not so intensely hunted.
Answer: Bottleneck
The Afrikaner population of Dutch settlers in South
Africa is descended mainly from a few colonists.
Today, the Afrikaner population has an unusually
high frequency of the gene that causes
Huntington’s disease, because those original Dutch
colonists just happened to carry that gene with
unusually high frequency.
Plickers!
For the following questions, hold your PLICKER with
the letter of the correct answer facing up.
Hold your card level.
Everyone’s plicker is different, every answer choice
is on a different side. There’s no point trying to copy
the way you hold your plicker. Answers are
anonymous, so please put what you think is the
right answer so we can discuss. The goal is to learn
from your mistakes!
The fact that South and Central American
Indians are nearly 100% type O for the ABO
blood system is best explained as being the
result of:
a) genetic drift
b) natural selection
c)
the founder principle
The fact that South and Central American
Indians are nearly 100% type O for the ABO
blood system is best explained as being the
result of:
a) genetic drift
b) natural selection
c)
the founder principle
Which of the following is true of genetic
bottlenecks?
a) They occur when there are major
environmental changes that alter natural selection
so that most members of a species die before
reproducing.
b)
The result is usually increased genetic
diversity in a population following a genetic
bottleneck.
c)
They reduce the fertility of the survivors.
Which of the following is true of genetic
bottlenecks?
a) They occur when there are major
environmental changes that alter natural selection
so that most members of a species die before
reproducing.
b)
The result is usually increased genetic
diversity in a population following a genetic
bottleneck.
c)
They reduce the fertility of the survivors.
Mutations must occur in what types of cells
before they can be important in evolutionary
change within a population?
a. gametes
b. somatic cells
c. autosomes
d. blood cells
Mutations must occur in what types of cells
before they can be important in evolutionary
change within a population?
a. gametes
b. somatic cells
c. autosomes
d. blood cells
The movement of alleles from one population to
another by the migration of individuals is called?
a. gene flow
b. genetic drift
c. natural selection
d. genetic bottleneck
The movement of alleles from one population to
another by the migration of individuals is called?
a. gene flow
b. genetic drift
c. natural selection
d. genetic bottleneck
Which of the following is not a type of genetic
drift:
a. bottleneck effect
b. founder effect
c. gene flow
Which of the following is not a type of genetic
drift:
a. bottleneck effect
b. founder effect
c. gene flow
A plant population is 50% BB and 50% bb. After
random mating among all these individuals, we
expect
a) the F1 to be 100% Bb
b) the F1 to be 50% BB and 50% bb
c) the F1 to be 25% BB, 50% Bb, and 25% bb
d) the F1 to be randomly composed of BB, Bb, and
bb individuals
A plant population is 50% BB and 50% bb. After
random mating among all these individuals, we
expect
a) the F1 to be 100% Bb
b) the F1 to be 50% BB and 50% bb
c) the F1 to be 25% BB, 50% Bb, and 25% bb
d) the F1 to be randomly composed of BB, Bb, and
bb individuals
Traditionally, human males with the genetic disease
hemophilia often died before they reached reproductive
age. If modern medical treatment allows most
hemophiliacs to lead long and fruitful lives, what will
happen to the frequency of the allele responsible for
hemophilia?
a) It should increase in frequency.
b) It should decrease in frequency.
c) It should not change in frequency.
d) Change in frequency will be unpredictable due to
random events.
Traditionally, human males with the genetic disease
hemophilia often died before they reached reproductive
age. If modern medical treatment allows most
hemophiliacs to lead long and fruitful lives, what will
happen to the frequency of the allele responsible for
hemophilia?
a) It should increase in frequency.
b) It should decrease in frequency.
c) It should not change in frequency.
d) Change in frequency will be unpredictable due to
random events.
Which of the following factors is most likely to
contribute to gene flow between populations?
A) random mating
B) migration
C) mutation
D) genetic drift
E) inbreeding
Which of the following factors is most likely to
contribute to gene flow between populations?
A) random mating
B) migration
C) mutation
D) genetic drift
E) inbreeding
Evolution by natural selection works best on a
population having no variation.
A) True
B) False
Evolution by natural selection works best on a
population having no variation.
A) True
B) False
Which statement most accurately reflects what
population geneticists refer to as "fitness"?
A)
Fitness is the measure of an organism's
adaptability to various habitats.
B)
Fitness reflects the number of mates each
individual of the population selects.
C)
Fitness refers to the relative health of each
individual in the population.
D)
Fitness is a measure of the contribution of a
genotype to the gene pool of the next generation.
Which statement most accurately reflects what
population geneticists refer to as "fitness"?
A)
Fitness is the measure of an organism's
adaptability to various habitats.
B)
Fitness reflects the number of mates each
individual of the population selects.
C)
Fitness refers to the relative health of each
individual in the population.
D)
Fitness is a measure of the contribution of a
genotype to the gene pool of the next generation.
Wednesday Exit Ticket
4. Four species with a homologous section of
DNA have the following nucleotide sequences:
According to these sequences, which two
species are the most closely related?
a. Species 1 and 2
b.Species 1 and 3
c. Species 2 and 3
d.Species 2 and 4
Wednesday Exit Ticket
5. The embryos of several types of animals
look very similar and develop in almost the
same manner, especially in the early stages.
What do these physical similarities indicate?
a. The organisms have analogous structures.
b. The organisms have similar adaptations.
c. The organisms have not evolved much.
d. The organisms have a common ancestor.
Friday – 2/10
IT’S TEST DAY!
• Take your review and your notes out on your
desk.
• Take 5 minutes to look over your notes and
ask me any questions you may have.