Transcript document

Honors Project 2:
The Human
Variation
Project
Due: 3/21
Eastern hognose snake, Heterodon platirhinos
Virginia opossum, Didelphis virginiana
How might traits, like ‘playing
dead,’ first evolve?
Fainting Goats http://www.youtube.com/watch?v=we9_CdNPuJg
Procedure:
Human Variation Project
Background:
As Gregor Mendel demonstrated with his
studies of pea plants, organisms can vary widely in a
range of traits. Humans also show a variety of
characteristics in height and in the color of their hair,
skin
and eyes. Sometimes differences among individuals can
be striking: people who have jagged, piercing teeth,
footlong
necks, or fur that covers their body. But these
phenotypic features are not always the result of genes;
environment can also be a critical factor.
People vary widely in heritable traits
Outline of Your Task:
1) Sort through the human traits on the following pages. Identify two inherited traits
and two non-inherited traits.
2) Create a PowerPoint presentation (read details and find an example on proceeding
slides).
3) Evolve a new type of human (refer to upcoming description and example).
Step #1:
Human Variants
Directions: Explore the following range
of traits among people. Can you identify
which characteristics are hereditary and
which are not?
Mutant
Muscle
Bigger muscles, faster whippet http://www.thetech.org/genetics/news.php?id=56
Myostatin & Muscle Growth –
http://videos.howstuffworks.com/sciencentral/2698-myostatin-andmusclegrowth-video.htm
Genetic mutation turns tot into
superboy - http://www.msnbc.msn.com/id/5278028/
Questions:
1) Describe the genetic difference between a whippet and a bully whippet dog. Explain how
mutations caused this difference.
2) A baby boy from Germany was discovered to have a mutation that blocks the regulation of
a gene that limits muscle growth. How did this mutation effect him? Are there clues this gene
was inherited? Explain.
Tree Man
Cause of Treeman’s Barklike
Growth http://www.cnn.com/2008/HEALTH/co
nditions/10/02/treeman.wart.skin.disor
der/index.html
Bark-like skin –
http://abcnews.go.com/Health/Medical
Mysteries/story?id=5535375&page=1
‘Branches’ Begin to Regrow http://www.foxnews.com/story/0,2933,58053
3,00.html
Questions:
1) What is Keratin? How might a virus infection like HPV cause a gene to make
too much keratin?
2) HPV infected Dede Kosawa’s the somatic cells, such as his skin. Is it possible
for him to pass on this trait if he were to have more children?
Brown Eyes Blue
Genetic mutation makes those
brown eyes blue http://www.msnbc.msn.com/id/22934464/wid/1
1915773
Ancestor of blue eyes –
http://www.sciencedaily.com/releases/2008/01/
080130170343.htm
Blue eyes result of ancient genetic
'mutation' http://www.telegraph.co.uk/science/sciencenews/3323607/Blue-eyes-result-ofancientgenetic-mutation.html
Questions:
1) How did scientists trace the origin of all people with blue eyes to a common ancestor whom
lived between 6,000 – 10,000 years ago?
2) Define sexual selection. How is it different from natural selection? Speculate on how sexual
selection might have caused blue eyes to become common among some racial groups.
Fewer is Wiser
Are people without wisdom teeth more
highly evolved? http://health.howstuffworks.com/humanbody/parts/nowisdom-teeth.htm/printable
The Evolution of Cooking: A Talk With
Richard Wrangham –
http://www.edge.org/3rd_culture/wrangham/wrangham_ind
ex.html
Troubles with Human Wisdom Teeth http://www.sciencedaily.com/releases/2007/09/070926172
246.htm
Questions:
1) Listen to the interview with Harvard anthropologist, Richard
Wrangham. How could have cooking changed the evolution of the
human jaw? Explain the reasoning of this hypothesis.
2) Refer the photo on the right. Compare the jaw of the chimpanzee
(left) to that of the human (right). Which jaw is shorter? Do they have
the same number of teeth? How might a change in jaw length cause
wisdom teeth to become a vestigial trait?
Sight for Smell
Primates Trade Smell for Sight http://www.primates.com/misc/smellsight.html
Evolution smell & vision in primates http://www.plosbiology.org/article/info:do
i%2F10.1371%2Fjournal.pbio.0020033
The Real Life of Pseudogenes –
http://papers.gersteinlab.org/eprint/scia
m2/reprint.pdf
Questions:
1) Compared to other mammals humans have a poor sense of smell. In contrast, people,
apes, and most Old World Monkeys are trichomatic (can see blues, greens, and reds).
Use the provided website links to explain how and why this shift between our senses may
have occurred.
2) Define what a pseudogene is. Describe the olfactory receptor (OR) pseudogenes in
people. How might OR pseudogenes provide evidence for human ancestors evolving sight
over smell.
Pseudogenes &
Vitamin C
What genes did we lose to become human? http://adaptivecomplexity.blogspot.com/2008/01/what-genes-didwe-lose-to-become-human.html
Human GULOP pseudogene http://sandwalk.blogspot.com/2007/02/humanguloppseugogene.html
Scurvy http://www.limestrong.com/scurvy.htm
Questions:
1) What is scurvy? How does a lack of ascorbic acid (vitamin C) cause this disease?
2) If humans don’t eat citrus fruits or vegetables with vitamin C, we develop scurvy.
However, people have a ‘broken’ gene for making this vitamin. For instance, cats
have a working vitamin C gene and synthesize it as part of their metabolism - so
they don’t need to eat oranges or limes. Explain why humans have this pseudogene.
Apendixless
Your Appendix http://www.health24.com/Man/Cm_x_Cm/7483216-3219-3227,34811.asp
Vestigial features –
http://txtwriter.com/Backgrounders/Evolution/EVpa
ge12.html
The vestigiality of the human appendix http://www.talkorigins.org/faqs/vestiges/appendix.h
tml
Questions:
1) What is the appendix? Can you live without it? Out of every 100,000 people, how
many are estimated to be born without an appendix?
2) What is a cecum? How is the cecum important to herbivores and some
omnivores? Describe how the human vermiform appendix and the cecum are
homologous structures. What makes it also a vestigial structure?
Entwined Senses
Synesthesia http://faculty.washington.edu/chudler/syne.
html
Hearing colors - http://www.schoolforchampions.com/senses/synesthesia.htm
It’s a beautiful day http://www.synspectrum.com/synesthesia.h
tml
Questions:
1) What is synesthesia? Describe how people with this trait perceive the world
differently than a typical person.
2) Might this be an inherited trait? If so, describe how it might be passed on from
generation to generation. Might synthesthesia be a derived trait compared to
those people who don’t share this ability?
Skin Selection
The Biology of Skin Color: Black and White http://www.pbs.org/wgbh/evolution/library/07/3/tex
t_pop/l_073_04.html
UV Light, Vitamin D3, and Folate influence on
Skin Pigmentation http://www.suite101.com/content/uv-light-vitamind3-andfolate-influence-on-skinpigmentationa252619
Folate & Fertility & Skin Color http://blogs.discovermagazine.com/gnxp/2009/04/
folatefertility-skin-color/
Questions:
1) Why is vitamin D important for people? How does sunlight help us make it?
What
is folate and why is it important for pregnancy?
2) How can skin color be understood in the context of vitamin D and folate? Next,
use the concept of natural selection to explain why different races of people have
darker or lighter skin.
Blue Skinned
The Blue People of Troublesome
Creek –
http://www.indiana.edu/~oso/lessons/
Blues/TheBlues.htm
The Blue People of Troublesome
Creek KY –
http://scienceray.com/biology/humanbiology/theblue-people-oftroublesome-creek-ky/
Those Old Kentucky Blues http://www.sciencecases.org/blue_pe
ople/blue_people.pdf
Questions:
1) Can you determine if “blueness” is a heritable condition? If so, what might be
the specific genetic pattern of inheritance?
2) Explain how geographic isolation may have influenced the prevalence of the
blue-skinned trait among the people of Troublesome Creek.
Show Some Skin
Human Hairless Gene http://www.keratin.com/aa/aa003.shtml
Atrichia in people http://www.springerlink.com/content/upu6mg2wb62j8
3x5/
Sphynx cat http://www.cfainc.org/breeds/profiles/sphynx.html
Questions:
1) How did the “hairless” gene (hr) in mice help researchers locate a
homologous gene in humans?
2) Follow the link – “Atricia in people” to read the abstract by Zlotogorski,
Ahmad, and Christiano. Notice how they report that a deletion in an exon
caused a frameshift mutation. Explain what this means and why it could
result in hairlessness.
Albinism
Evolution in Black & White http://www.smithsonianmag.com/sciencenature/Evolution-in-Black-andwhite.html?c=y&page=2
Albino cavefish –
http://www.sciencedaily.com/releases/2005/1
2/051220000639.htm
What causes albinism? http://www.scientificamerican.com/article.cfm
?id=killing-albinostanzania-albinism
Questions:
1) Albinos in certain regions of the world, such as in East Africa, may face discrimination and
physical abuse by other people. However, in some species, such as many cave-dwelling
animals, albinism is the norm. Describe a species that natural selection has favored a lack of
pigment.
2) One form of albinism is caused by a mutated pigmentation gene called OCA2. This
mutation effects tyrosine. How could a mutation result in the loss of this amino acid? What
pigment does tyrosine normally get converted into which albinos lack?
Out of Thin Air
Mutation in key gene http://www.guardian.co.uk/science/2010/jul/02/mutationgene-tibetans-altitude
Tibetans adapted to high altitude http://berkeley.edu/news/media/releases/2010/07/01_tib
etan_genome.shtml
Scientists uncover the genetic secrets http://www.eurekalert.org/pub_releases/2010-06/nescsut060510.php
Questions:
1) On the Tibetan plateau there is 40% less O2 than at sea level. How did a
change in the EPAS1 gene offer greater biological fitness to those Tibetans
possessing this mutation?
2) Describe how the process of natural selection helped Tibetans adapt to this
harsher, lower oxygen environment.
Speedy Genes
What makes the perfect marathon runner http://www.telegraph.co.uk/sport/othersports/athletics/lo
ndon-marathon/5192764/London-Marathon-2009-whatmakes-the-perfect-marathon-runner.html
Potential Use of Gene Transfer http://www.nature.com/mt/journal/v15/n10/full/6300278a
.html
Fear of gene doping http://www.msnbc.msn.com/id/10628586/
Questions:
1) Describe how mutations and other changes in the ACTN3 and EPO genes can
naturally enhance an athlete’s performance.
2) Researchers have mutated PPAR-delta and PEPCK-Cmus genes in mice. Do you
think these and naturally occurring mutations in people may one day lead to gene
doping? Explain.
Gigantism
Gigantism http://endocrinedisorders.healthcares.net/gigantism.php
Giants - Part 1 - Pituitary Gigantism and
Acromegaly http://www.youtube.com/watch?v=Ebhf1q
KVA9A
The Science and Spirit of Giants and
Dwarfs http://abcnews.go.com/2020/story?id=340
4733&page=2
Questions:
1) Giagantism is typically caused by a benign tumor on the pituitary gland. Because
the pituitary gland is comprised of somatic cells, will a person with this trait pass it
on to their offspring?
2) What hormone does the pituitary gland secrete that causes gigantism? Besides
being tall, what other features do they usually have.
Human Horns
Cutaneous horn http://www.skinsight.com/adult/cutaneousHorn.htm
Cutaneous horn –
http://emedicine.medscape.com/article/1056568overview
Giant Cutaneous Horn http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2763
752/
Questions:
1. Cutaneous horns typically grow on the sun-exposed areas of people that are
fifty years or older. Skin, made of somatic cells, may accumulate mutations
from repeated sunburns. Would children likely inherit these horns from an older
man that had sons and daughters late in life? Explain.
2) What protein makes-up the cutaneous horns. How are cutaneous horns similar
in composition to a rhino’s horn?
Xtra Flexx
Human Mutations: Bone Mutation http://www.youtube.com/watch?v=vtW3dMZLrtE&NR=1
Floating Forelimbs and Clavicles –
http://www.askabiologist.org.uk/answers/viewtopic.php?id=3
590
No bones about it: Gene vital to skeleton http://www.sciencenews.org/pages/pdfs/data/1997/15123/15123-05.pdf
Questions:
1)
In the 19th Century, a sailor came to the Cape Verde Islands. The man had
a rare mutation on a gene called Cbfa1 that disrupts normal bone
development. He had seven wives & now about a thousand of his
descendants inherited a trait that reduces the clavicles (collarbones).
Describe how this is an example of the founder effect.
2)
Cats, dogs, and other fast-running four-legged animals have reduced
clavicles, similar to some people from the Cape Verde Islands. Explain how
a more flexible shoulder might be a useful adaptation.
The Spectrum
of Aging
Girl Who Doesn't Age 'Infant' of Family http://www.youtube.com/watch?v=GpVFW
R7ay90&feature=fvw
Progeria Baby - NJN News Health watch
Report http://www.youtube.com/watch?v=C_0gPI7
qTgc
John Tacket is
15 years old
Anti-Aging Secrets in Girl's Genes? http://news.discovery.com/human/brookegr
eenberg-anti-aging-genetics.html
Questions:
1) People with Brooke Greenberg’s condition and those with progeria may not pass on their
mutations to offspring. However, might scientists one day learn to change the rate by
which we get older by learning from how these mutations alter the aging spectrum?
Explain.
2) What are “centenarians?” Are they genetically different from the average person? Might
these genes be inherited?
Webbed Feet
and Hands
Syndactyly –
http://emedicine.medscape.com/article/124
4420-overview
Apoptosis http://www.biologydaily.com/biology/Apopto
sis
Cell Death and the Formation of Digits and
Joints http://www.ncbi.nlm.nih.gov/bookshelf/br.fc
gi?book=dbio&part=A3972
Questions:
1) How does the process of “apoptosis” or programmed cell death provide an explanation for
how fingers and toes form, or do not clearly form.
2) Look at the anatomy of a duck’s foot. How does its structure relate to how it functions?
Among a group of “normal-toed” birds that have feet resembling those of the chicken, how
might mutations (that code for programmed cell death) and natural selection enable birds
with mutated feet to occupy a new niche?
A Piercing Bite
Tooth Filing –
http://www.ask.com/wiki/Tooth_filing
Season for Tooth Filing http://www.indo.com/indonesia/news74.html
National Geographic: Taboos http://channel.nationalgeographic.com/series/t
aboo/1851/Photos#tab-Photos/0
Rank & dominance displays http://www.chimpanzoo.org/african_notecards/
chapter_10.html
Questions:
1) Certain anatomical alterations such as putting collagen into the lips, silicon into breasts,
and tooth filing require a trained participant. Individuals hoping for fuller lips and enlarged
breasts are not so different from those that desire pointed teeth. Explain how such
modifications could advertise a higher social status.
2) The chimpanzee, our closest living animal relative, demonstrate rank through aggressive
displays. Compare and contrast how human and male chimps demonstrate their ranking.
Got Lactase?
Lactose Intolerance http://www.gicare.com/pated/ecdgs24.htm
Lactose Tolerance in Humans http://www.scientificamerican.com/article.cfm?id=lactos
e-toleraence
Got Lactase (Understanding Evolution) http://evolution.berkeley.edu/evolibrary/news/070401_la
ctose
Questions:
1) All mammals drink milk when they are young but this behavior typically stops by
adolescence. Digestion of milk requires the enzyme lactase which breaks down
the sugar lactose in milk. Most adult mammals stop making lactase by this point.
How did this mutation influence the diet of those people who inherited this trait?
2) Describe, through the process of natural selection, how the lactase gene was
favored in some societies.
Step #2
Create a PowerPoint presentation of two inherited and two
non-inherited traits after you have researched them.
Your Specific Tasks:
1. For each inherited and non-inherited trait, create a PowerPoint slide that describes how
the trait is acquired, its possible genetic characteristics (recessive, dominant, X-linked,
etc. and what chromosomes it might have been found on). Finally describe if certain
populations (races, genders, etc.) are more prone to getting such a characteristic or if it
occurs across all human groups.
2) Include a picture of a person whom shows the characteristic or an image of the trait
(examples: effected blood cells, receptor proteins, etc.).
3) Answer the question(s) posted for each trait. Re-copy the question and answer it, as
shown in the example.
4) Include a reference section of the websites used in your research (website name, url, and
date and time you last visited it).
See next slide for an example of a PowerPoint slide
Example:
Congenital Generalized Hypertrichosis
- Congenital Generalized Hypertrichosis (CGH) a.k.a. “Werewolf syndrome”
is an X-linked, dominant allele.
-Forty confirmed cases of CGH occur today in populations in Europe,
North America, and Asia. CGH has been reported since the Middle
Ages.
- CGH may be an atavistic trait – the re-emergence of
an evolutionarily ancient characteristic that is normally
suppressed.
Danny Ramos Gomez
Questions & Answers
In certain environments, how might CGH be an adaptation? Support your answer with
examples of ‘furry’ species of rhinos and elephants in nature.
During the last Ice Age, woolly rhinos and mammoths lived in Eurasia. Their fur was likely an
adaptation to the cold, windy steppes in which they lived. Natural selection might favor
people with CGH if humans were to live in a similar environment for many generations.
Real-Life ‘Werewolves’ - http://abcnews.go.com/Primetime/story?id=2258069&page=1
References:
10/23/2010 7 PM
Modern 'Wolfmen' May Have Inherited Ancient Gene –
10/23/2010 8 PM
http://www.nytimes.com/1995/05/31/us/modern-wolfmen-may-have-inherited-ancient-gene.html
Step # 3:
Your Task:
Imagine a culture where a trait might be favored through sexual
selection or by natural selection such as climate. Choose four inherited
traits from this project (two can be those you researched for parts 1 &
2). Combining these features, draw them so they are adapted to this
new cultural or natural environment. Scan pix into project.
Scanned Student
Drawing Here!
Visualize a hairless,
powerfully built, blue-skinned
person with piercing, blue
eyes, webbed hands and feet.
Could such a human ever
exist?
Example:
The Azuls live on a nearly submerged planet. Descended from people
that settled this marine world in the outer galaxy, these humans are
well adapted to an ocean-dwelling lifestyle. Mates with the bluest eyes
are highly sought after.
The traits
depicted (on
right)
represent
characteristics
In the future
human (left).
Grading Criteria of PowerPoint Presentation
40 = Excellent
35 = Good
30 = Fair
25 = Poor
0 = Not Acceptable
1) Presentation of Traits: (out of 80 points):
Two inherited traits Research: genetics, populations effected, etc.
One image per trait (one pix should be original).
Questions answered accurately & thoroughly.
References (website name, url, date/time last visited).
Two non-inherited traits - Research: acquisition of trait, populations effected.
One image per trait (one pix should be original).
Questions answered accurately & thoroughly.
References (website name, url, date/time last visited).
20 = Excellent
15 = Good
10 = Fair
5 = Poor
___
___
0 = Not Acceptable
2) Evolve a new type of human: (out of 20 points)
___
Combined 4 inherited traits from project to “breed” a new type of human.
Includes a scanned-in picture of person & an explanation of their adaptations.
 Drawing shows detail and effort.
 Adaptations are explained in the context of cultural and/or natural selection.
 Image or explanation is creative and original.
Total:___
Note: Be careful that all writing is in your OWN WORDS. Do not simply “cut & paste”
information. Plagiarized material will result in a failing grade and disciplinary action.