The Future
of the
Past
DNA
DNA
DNA studies can
uncover new relationships
and disprove the ones
you thought you had.
chromosome
pair
chromosome
pair
In color with clickable links at http://udel.edu/~tdoherty/DNAweb11s.pdf
DNA, Chromosomes and Genes
‹DNA (DeoxyriboNucleic Acid): in most all body cells
- Very long twisted double helix structure, composed of
a sugar (deoxyribose), a phosphate and two base pairs
- Organized into chromosome pairs: 23 in nucleus of cell
plus mitrochondrial-DNA outside cell nucleus
- Your DNA, stretched end to end, goes to moon and back
‹Chromosome pairs: 23 strung along our DNA chain
DNA
-- Dog: 39 chromosome pairs, cat 19, mosquito 3, rice 12
- One sex chromosome pair: XX=female, XY=male
chromosome
- plus 22 autosomes (non-sex) chromosome pairs
pair
‹Genes: an estimated 25,000 genes on our 23 chromosomes
- Genes are groups of base pairs along a chromosome chain.
- How base pairs are grouped into genes at fixed positions
on the chromosome chain define us as unique human beings.
© Spring 2011 Thomas P. Doherty
ALL Class site:
http://udel.edu/~tdoherty/DNAweb11s.pdf
for clickable links
1
Cell Structure
Nucleus
contains 23 chromosome pairs (½ from each parent)
Y-chromosome from father only to his sons
X-chromosome from father only to his daughters
DNA
chromosome
pair
Mitochondria, DNA
to all children from mother;
only outside the nucleus
Chromosomes are threadlike “packages” of genes and other DNA
cell drawing ©2004 Pearson Education, Inc. in Tortora, Funke & Case, “Microbiology An Introduction” 8th edition
Mitochondrion
‹mitochondria:
~1,000 (1K)/cell
‹~16K base pairs
/mitochondrion
‹none in nucleus
‹where energy is
generated for
cell metabolism
‹contains mtDNA
only from mother
‹only changed by
rare mutation
‹not thought to
carry much
genetic code
drawing ©2004 Pearson Education, Inc. in Tortora, Funke & Case, “Microbiology An Introduction” 8th edition
© Spring 2011 Thomas P. Doherty
ALL Class site:
http://udel.edu/~tdoherty/DNAweb11s.pdf
for clickable links
2
Human Chromosomes
DNA
chromosome
pair
graphics from http://www.smgf.org/education/animations/four_types.jspx
The Structure of
DeoxyriboNucleic Acid
(DNA)
‹DNA looks like a twisted ladder
‹Has sugar-phosphate backbone
‹Base pairs form rungs of ladder
‹Has only 4 bases, only 2 base pairs:
1. adenine-thymine (A-T) ( - )
2. cytosine-guanine (C-G) ( - )
‹Four configurations: A-T, T-A, C-G, G-C
Weak
Hydrogen Bonds
Between Bases
Sugar-Phosphate
Backbone
‹mtDNA: has ~16
thousand base pairs
‹Y-chromosome: ~50 million base pairs
for more: http://blairdna.com/dna101.html
© Spring 2011 Thomas P. Doherty
ALL Class site:
http://udel.edu/~tdoherty/DNAweb11s.pdf
for clickable links
3
Chemical Structure of Bases
‹DNA: 4 bases, 2 base pairs:
1. adenine-thymine (A-T) ( - )
2. cytosine-guanine (C-G) ( - )
For those who really had to know
Weak
Hydrogen Bonds
Between Bases
DNA
‹Each base pair: 3 double-bond rings
‹Each DNA “rung” is relatively flat
Testing Your DNA
1. adenine-thymine (A-T) ( - )
2. cytosine-guanine (C-G) ( - )
‹Sequence, esp. repeat units, of these base
pairs (bp) determines your genetic code
‹of 50M base pairs, Y-DNA focus is on
Weak
Hydrogen Bonds
Between Bases
a few “markers”
‹markers contain ~2-5 bp (e.g. ATCG)
repeated head-to-tail numerous times
‹mutation: delete or add repeat unit
repeated head-to-tail numerous times
‹improve odds of finding relationships:
- normally a cheek swab is taken
- recruit more participants
- test 37 or more markers/participant
for more: http://blairdna.com/dna101.html
© Spring 2011 Thomas P. Doherty
ALL Class site:
http://udel.edu/~tdoherty/DNAweb11s.pdf
for clickable links
4
Why Are My 25,000 Genes Unique?
‹
‹Genes are groupings of base pairs on a chromosome chain.
- Human DNA is 99.9% the same; we study 0.1% difference
- Geneticists have identified specific locations on chains
to study base pair groupings (genes), called “markers”
‹
‹Markers are assigned a specific identifying code.
- Y-DNA markers have a DYS# code, e.g. 393, 464a, CDY b
- Some markers, not all, have been connected to a genetic trait.
‹
‹Gene mutation rates: vary markedly among genes, e.g.
- Both Y-DNA and mtDNA pass “unchanged” from parents
- Y-DNA mutates 0.002 times/marker/generation
- mtDNA mutates less than 0.0002 times/marker/generation
‹
‹Recombination: mixing of each parent’s 22 autosomes
- each parent contributes ½ part of each of their 22 autosomes
the recombined ½ parts (called gametes) join at conception
‹
‹Testing your DNA:
- Was blood sample, now cheek swab (better for queasy men).
- Widespread autosomal DNA testing first offered 2010
Random Infrequent Mutations
are measured in ““markers”
markers”
‹Test markers known to mutate more often
‹Y-DNA mutates .002 times/marker/generation
- 25, 37, 67 “markers” commonly tested
- now best way to find common recent ancestors
- if female, you must recruit a male relative
‹mtDNA mutates <.0002 times/marker/generation
- mtDNA: hypervariable (HVR) regions I and II
- too few differences to detect recent [1000 yr] descent
- but can determine ancestral heritage
- our mtDNA differs, depending on which cell it’s in
© Spring 2011 Thomas P. Doherty
ALL Class site:
http://udel.edu/~tdoherty/DNAweb11s.pdf
for clickable links
5
Are We Part
Neandertal
?
Neandertal?
‹Draft results*
- Neandertals 99.84%
identical to humans
- Used SNP markers: mutate only once in human history
- Europeans/Asians share 1-4% DNA with Neandertals/Neanderthals
- Africans share no DNA with Neandertals
‹Very small sampling
- Three 38,000 year old female Neandertals from Croatia region
- Not many samples available: ice age glacier damage
*R.Green, A Draft Sequence of the Neandertal Genome, Science v.328, #5979, p.710 (7 May 2010)
Also see: http://www.sciencemag.org/special/neandertal/feature/index.html (graphic)
Markers
DNA
Each marker has a
different mutation rate.
Mutations occur often
during recombination.
from http://www.smgf.org/education/animations/mutation.jspx
© Spring 2011 Thomas P. Doherty
ALL Class site:
http://udel.edu/~tdoherty/DNAweb11s.pdf
for clickable links
6
Markers Commonly Tested
compared to Cambridge Reference Standard
‹Test Regions of more recent mutation
- some markers of known genetic traits, others “junk” area
- Y-DNA: 37($119-169), 67 ($269); autosomal ($293)
- mtDNA: hypervariable (HVR) regions I and II
‹Large samplings needed for best results
‹Testing Companies: see http://genetealogy.com
- http://www.familytreedna.com 90% of family projects
- http://dnaancestry.com (dnagroups) – with ancestry.com
-- from http://www.relativegenetics.com/relativegenetics/index.jsp
-- Sorenson is partner: http://sorensongenomics.com
‹Nat’l
Geographic Genographic Project (deep ancestry):
- see https://www3.nationalgeographic.com/genographic
‹Sampling process: http://davedorsey.com/dna.html
Y
-Chromosome Inheritance
Y-Chromosome
Father passes Y-chromosome unchanged*
to every son and to none of his daughters
The Y-DNA of my great-grandfather
(Thomas F. Doherty) dies with me.
‹only one of his sons had a son (my dad).
‹Genetically, I was an only child.
‹I have no sons.
Where was my great-grandfather born?
‹born 15 May 1850 [Bible] in “Ireland” [many sources]
st Child’s birth record: father b “Co Clare, Ireland”
‹1st
‹1880s Boston photo of family: “brother James Doherty”
‹1881 Photo: man of Limerick; same as man in Boston?
‹My 67 markers:part of Doherty project at FamilyTreeDNA
* a random mutation (.002/marker/generation)
© Spring 2011 Thomas P. Doherty
ALL Class site:
http://udel.edu/~tdoherty/DNAweb11s.pdf
for clickable links
7
Y
-Chromosome Inheritance
Y-Chromosome
Are these people related?
1881 Limerick
1875-90? Boston
My
My great-grandfather
great-grandfather
(Thomas
(Thomas F.
F. Doherty)
Doherty)
born
born 15
15 May
May 1850
1850
Co.Clare
Co.Clare
Ireland
Ireland
d.1904
d.1904
Chicago
Chicago
my
my grandfather
grandfather >>
>>
(Edward
(Edward James
James
Doherty)
Doherty)
My
My Dad
Dad >>
>>
(Maynard
(Maynard
Thomas
Thomas
Doherty)
Doherty)
(2
(2 photos)
photos)
Me
Me >>
>>
(2
(2 photos)
photos)
1880s
1880s Boston
Boston “brother
“brother James
James Doherty”
Doherty” and
and family
family
[Generations to]
Most Recent
Common
Ancestor
[[MRCA:
MRCA:
50% likely that
two individuals
are related
related]]
Note: 36/37 means
36 markers match
out of 37 tested –
could be higher certainty
than 15/15.
Some markers of known genetic
traits, others in ““junk”
junk”
junk” area.
chart from http://www.relativegenetics.com (Y-DNA)
© Spring 2011 Thomas P. Doherty
ALL Class site:
http://udel.edu/~tdoherty/DNAweb11s.pdf
for clickable links
8
Sample Y-DNA Results from FamilyTreeDNA.com
http://www.familytreedna.com/myhttp://www.familytreedna.com/my-ftdna/yftdna/y-dnadna-dys.aspx
Locus = marker [I had 67 tested]
DYS# = ID# of locus: chosen because alleles differ often,
but not too often
Alleles = # of repeating base pairs at that marker
If your # of alleles differs from someone else, mutation(s)
have occurred between your MCRA
(Most Recent Common Ancestor) and
either one or both of you.
Matching Results:
[groups of cousins]
>>
[Generations to]
Most Recent Common Ancestor
[[MRCA:
MRCA: 50% likelihood that two individuals are related
related]]
Number of Generations to 50%
likelihood of a common ancestor
Some markers are of known genetic traits, but most in ““junk”
junk”
junk” area
17 generations goes back to 15th or 16th
century, near the limit of most paper trails
(Y-DNA)
about 3
generations
for 67
markers
chart from http://nitro.biosci.arizona.edu/ftDNA/TMRCA.html
© Spring 2011 Thomas P. Doherty
ALL Class site:
http://udel.edu/~tdoherty/DNAweb11s.pdf
for clickable links
9
The
The Determination
Determination of
of aa Boy,
Boy, Age
Age 15
15
A
A Possible
Possible Con
Con of
of Testing
Testing Your
Your DNA
DNA
Warning for anyone who has fathered a child
and wants that fact to remain a secret
© Spring 2011 Thomas P. Doherty
ALL Class site:
http://udel.edu/~tdoherty/DNAweb11s.pdf
for clickable links
10
Haplotype: Y
-DNA & mtDNA
Y-DNA
Haplotype: DNA inherited unchanged
Haplogroup
Haplogroup:: collection of similar haplotypes
‹New haplotype from mutation: random time/place
‹Y-DNA min. mutations .002/marker/generation:
- for combined mutations in 10 generations:
-- 12 markers tested: .24; 37 markers: .74
-- 2 unique paper trails to 10 gen: 1.5 mismatches
-- 2 unique paper trails to 5 gen: 0.5 mismatch
‹magnitude fewer mtDNA mutations: < .0002/m/g
- only 2 markers measured routinely
- maybe only 100-200 European mtDNA halotypes
- can confirm only a few paper trails
‹Mutation occurs frequently during recombination
My Mitochondrial DNA Line
1. Ruth Green m Thomas Whittier c1645 Newbury MA and had
2. Susanna Whittier m Jacob Morrill 1674 Salisbury MA and had
3. Susanna Morrill m Israel Webster 1714 Salisbury MA and had
4. Ruth Webster m Thomas Bagley 1747 Salisbury MA and had
5. Dolly Bagley m John Morrill c1781 Salisbury MA and had
6. Dolly Morrill m Richard Currier 1806 Amesbury MA and had
7. Dolly Currier m William Cushing Binney 1848 Amesbury MA =
8. Anna Sophia Binney m Charles W. Melcher 1881 St Louis MO =
9. Alice F. Melcher m Harold St.Clair MacMillan 1907 Hinsdale IL=
10. Mary A. MacMillan m Maynard T. Doherty 1931 Kankakee IL =
11. Me
I have my mother’s
mitochondrial DNA,
but I cannot pass it on.
There are a few rare
mtDNA types;
but mine is not rare.
© Spring 2011 Thomas P. Doherty
ALL Class site:
http://udel.edu/~tdoherty/DNAweb11s.pdf
for clickable links
11
Mitochondrial DNA Inheritance
Mother passes mtDNA unchanged*
to every son and daughter
purple circles (female)
* a very rare mutation (perhaps 1 per ~5000 generations),
but father passes none of his mtDNA to offspring
Hold the Presses: A new study shows several variations of
mtDNA in every human [Bert Vogelstein, Johns Hopkins
University School of Medicine, Nature (March 4, 2010)]
Deep Ancestry Migration Studies
http://www.testsymptomsathome.com/gti71_halogroups.asp (mt/Y-DNA)
http://www.dna-worldwide.com/ancestry-testing/female-ancestry (mtDNA)
https://genographic.nationalgeographic.com/genographic/index.html
UD
UD Life
Life Long
Long Learning:
Learning: Rise
Rise and
and Spread
Spread of
of Humans
Humans (Frank
(Frank Gay):
Gay): 9am
9am Fridays,
Fridays, Fall
Fall 2010
2010
© Spring 2011 Thomas P. Doherty
ALL Class site:
http://udel.edu/~tdoherty/DNAweb11s.pdf
for clickable links
12
The Future of the Past
Use DNA studies to confirm
suspected evidence of ancestry
Current work is mostly limited to descent through
Y-chromosome
mitochondrial DNA
green boxes (male)
16
purple circles (female)
great-great-grandparents
8
4
2
you >
you >
Y-DNA
mtDNA
If male, only 6.25% of your 2-greats-grandparents has your Y-DNA. Only 6.25% have mtDNA
The Rest of your DNA Story
‹Only
1/32 (3.12%) of your great-great-great-grandparents
has your mtDNA.
‹If
male, only 1/32 (3.12%) of 3-greats-grandparents
has your Y-DNA.
What about the other 22 chromosome pairs?
Autosomal DNA Testing
All 32 of your great-great-great-grandparents
have contributed to those 22 chromosome pairs.
... but it is much more complicated!
Both males and females participate equally!!
© Spring 2011 Thomas P. Doherty
ALL Class site:
http://udel.edu/~tdoherty/DNAweb11s.pdf
for clickable links
13
Tom’
Tom’s 3gr3gr-grandfathe
The Rest of
your DNA Story
If male, only 1/16 of
2g
-grandparents has
2g-grandparents
your mtDNA or Y
-DNA;
Y-DNA;
If male, only 1/32 of
3g
-grandparents has
3g-grandparents
your mtDNA or Y
-DNA
Y-DNA
not Tom’
Tom’s YY-DNA
not Tom’
Tom’s YY-DNA
Tom’
Tom’s grgr-grandfather
not Tom’
Tom’s YY-DNA
Tom’
Tom’s maternal grandmother
Tom’
Tom’s mtDNA
What about the other 22
chromosome pairs?
Autosomal
DNA Testing
Tom’
Tom’s grgr-grandmother
Tom’
Tom’s mtDNA
^^^
Tom’’s mtDNA
Harold St Clair MacMillan Tom
husband of
Alice Frances Melcher
Tom’
Tom’s
mtDNA
Autosomal DNA Testing
‹Autosomal DNA testing scans 22 chromosome pairs
‹Intergenerational DNA shuffle (recombination) occurs
- Except for occasional mutations, only Y-DNA and
mtDNA pass unchanged from father or mother
- Autosomes from each parent randomly recombine
before they combine during conception
‹Now good for relationships back to great-great grandparents and anthropological origins (1,000s of yrs ago)
‹Much more complicated
‹Need larger samplings (that is, more participants)
‹Genealogical research, analysis and database building
to confirm relationships: 6 generations is commercial.
© Spring 2011 Thomas P. Doherty
ALL Class site:
http://udel.edu/~tdoherty/DNAweb11s.pdf
for clickable links
14
Recombination
‹During
sexual reproduction, the mothers’
chromosome pairs and the father’s
autosome pairs (male XY is not a pair!)
undergo a recombination process.
‹Each parent contributes ½ part of each
recombined chromosome (called a gamete)
- mother’s and father’s gametes join at
conception to form a unique child
Animations
http://www.smgf.org/education/animations/four_types.jspx
http://www.smgf.org/education/animations/autosomal.jspx
http://www.smgf.org/education/animations/y_chromosome.jspx
http://www.smgf.org/education/animations/x_chromosome.jspx
http://www.smgf.org/education/animations/mitochondrial.jspx
Autosomal DNA
Graphic above is for one
chromosome pair for one
child; each chromosome pair
and each recombination is
different, so we are unique.
from http://www.smgf.org/education/animations/autosomal.jspx
© Spring 2011 Thomas P. Doherty
ALL Class site:
http://udel.edu/~tdoherty/DNAweb11s.pdf
for clickable links
15
DNA Study Warnings
‹Can
disprove genealogical descent
‹Early results say that about 5-10% of births
are “non-paternity events”*
*births where genetic father’s identity was a surprise:
http://www.childsupportanalysis.co.uk/analysis_and_opinion/choices_and_behaviours/misattributed_paternity.htm
‹Genetic
father may be surprised
Found a young girl, who suited him nice
Went to his papa to ask his advice
His papa said son, “I have to say ‘No’
That girl is your sister,
but your mama don't know...” Went to his mama who his papa had wed
And told his mama, what his papa had said
His mama she laughed, she says, “go son go
Your daddy ain't your daddy,
paraphrased
paraphrased from:
from:
but your daddy don't know...”
"Shame
"Shame and
and Scandal",
Scandal", traditional,
traditional, lead
lead vocalvocalPeter
Peter Tosh
Tosh (1965)
(1965) produced
produced by
by Coxone
Coxone Dodd
Dodd
The
The Autosomal
Autosomal Testing
Testing Companies
Companies
‹Relative
Finder (23 and Me): https://www.23andme.com
- Geared toward health, then ancestry: $399 or $99 +1 yr HGS@$9/mo
‹Family Finder (FamilytreeDNA): http://www.familytreedna.com
- Geared toward ancestry (not medical): $289 to participate
- Measures data point pairs: single nucleotide polymorphisms (SNPs)
- Measures 710,000 SNPs on 22 autosomal chromosomes
- If >500 SNPs in series match, cousins named “identical by descent”
- Doesn’t use sex chromosomes test data (e.g.Y-DNA): separate study
- Doesn’t use mtDNA test results: separate study
- Population Finder %: Assigns closeness to world population groups
‹Both “Finder” results uncover relationships for 5 generations:
Share
grandparents
greatgreat-grandparents
2-greatgreat-grandparents
3-greatgreat-grandparents
chart from: http://www.familytreedna.com/faq/answers/default.aspx?faqid=17#628
© Spring 2011 Thomas P. Doherty
ALL Class site:
http://udel.edu/~tdoherty/DNAweb11s.pdf
for clickable links
16
Autosomal
Autosomal Testing
Testing Results
Results
Avg. percentage of common ancestors’ DNA shared with cousin:
Sibling
50%
1st cousin
12.5%
2nd cousin
3.125%
3rd cousin
0.781%
3rd cousin
2X
removed
0.781%
4th cousin
0.195%
5th cousin
0.049%
66h cousin
0.012%
76h cousin
0.003%
86h
cousin
0.001%
chart from: http://www.familytreedna.com/img/familyfinder/whatpercentage.jpg
Another Possible Con of Testing Your DNA
Dear
Dear Abby
Abby by
by Jeanne
Jeanne Phillips
Phillips January
January 20,
20, 2010
2010
A question of paternity
DEAR
DEAR ABBY:
ABBY: My
My parents
parents divorced
divorced when
when my
my
older
older brother
brother and
and II were
were small.
small. Mom
Mom
remarried,
remarried, and
and II was
was adopted
adopted by
by the
the wonderful
wonderful
man
man who
who raised
raised me
me as
as his
his beloved
beloved daughter.
daughter. II
had
had limited
limited contact
contact with
with my
my biological
biological father,
father,
"Nate,"
"Nate," which
which seemed
seemed to
to please
please everyone.
everyone.
After
After my
my adopted
adopted dad
dad passed,
passed, Nate
Nate came
came back
back
into
into my
my life.
life. II have
have not
not seen
seen much
much of
of him
him but
but
he
he was
was present
present at
at my
my second
second marriage
marriage five
five
years
years ago,
ago, traveling
traveling across
across country
country to
to be
be there.
there.
Last
month
he
called
to
tell
me
he
has
been
Last month he called to tell me he has been
diagnosed
diagnosed with
with terminal
terminal cancer
cancer and
and has
has named
named
me
me as
as his
his heir
heir since
since my
my older
older brother
brother is
is
deceased.
deceased.
As
As aa birthday
birthday gift,
gift, II presented
presented him
him with
with aa box
box
from
from aa company
company that
that does
does genome
genome sequencing.
sequencing.
It
It allows
allows people
people to
to see
see their
their DNA
DNA and
and learn
learn
about
about their
their ancestry
ancestry as
as well
well as
as any
any healthhealthrelated
related issues.
issues. II enjoyed
enjoyed learning
learning about
about
genetics
genetics and
and thought
thought Nate
Nate would,
would, too.
too.
Imagine
Imagine how
how stunned
stunned II was
was when
when II learned
learned that
that
Nate
Nate is
is NOT
NOT my
my father.
father. The
The company
company has
has
assured
assured me
me there
there is
is little
little chance
chance the
the test
test is
is
wrong.
wrong.
II am
am close
close to
to my
my mother
mother and
and horrified
horrified that
that my
my
mother
mother kept
kept this
this secret
secret from
from me
me for
for more
more than
than
50
50 years.
years. II don't
don't want
want anyone
anyone to
to be
be hurt,
hurt, but
but II
need
need the
the truth.
truth. What
What do
do II do?
do?
Questioning
Questioning my
my DNA
DNA in
in S.F.
S.F.
DEAR
DEAR QUESTIONING:
QUESTIONING: Have
Have aa calm,
calm, private
private
conversation
conversation with
with your
your mother
mother and
and tell
tell her
her
what
what you
you have
have learned.
learned. If
If she
she denies
denies it,
it, have
have
the
the test
test repeated.
repeated. When
When you
you receive
receive the
the results,
results,
either
either apologize
apologize to
to your
your mother
mother or
or raise
raise the
the
subject
subject again.
again. She
She may
may know
know who
who your
your father
father
was,
was, or
or you
you may
may have
have been
been the
the result
result of
of an
an
opening
opening shot
shot in
in the
the sexual
sexual revolution,
revolution, aa chapter
chapter
your
your mother
mother may
may not
not care
care to
to revisit.
revisit.
Also for health reasons, question mother for identity of real father.
© Spring 2011 Thomas P. Doherty
ALL Class site:
http://udel.edu/~tdoherty/DNAweb11s.pdf
for clickable links
17
Genealogy: Fall 2011 offerings
Contact: Tom Doherty ([email protected]
([email protected]))
‹Genealogy:
‹Genealogy
Your Family Roots (12-1:45pm Th) – Jack Worton
Computer Workshops*(2-3:20pm Th): short weekly lecture
- Room 202 PC: Joyce Bischoff, Tom Freeman
- Room 214 PC: Carol Callaghan, Tom Doherty, Jane McKinstry, Suzanne Milazzo
- Room 219 Mac: Dick Cook, Linda McMeniman, Susan Kirk Ryan - Catalog
offers 2 workshops per room: 1. using LLL computers, 2. students with own laptops
In reality, both workshops are in the same room with 2-4 teachers.
- If you know someone who wants to take this course, encourage them
to apply now for UDelNetID# and password, so have for summer/fall
- Those using their own wireless laptops increase odds of taking course.
- Class Web Site: http://udel.edu/~tdoherty - changes soon after this semester ends
- Strongly recommend taking both lecture course and a workshop
‹Genealogy Interest Group (3:20-4:20pm Th): Rm
- Dick Burns, Linda McMeniman
4 Sep 2005
How Many Generations Back to
Your Most Recent
Common Ancestor
with Chimps?
- over 200,000 years ago!
Humans share 96% DNA with Chimps
but still 40 million genetic differences
99.9% of human DNA is identical.*
identical.*
migrated from Africa ~50,000 yrs ago
* * not counting the sex chromosomes which are quite different!
* http://news.nationalgeographic.com/news/2005/08/0831_050831_chimp_genes.html
© Spring 2011 Thomas P. Doherty
ALL Class site:
http://udel.edu/~tdoherty/DNAweb11s.pdf
for clickable links
18
Genealogy Computer Workshop Volunteers
We are here to help you find your past – please ask!
Rm 202 Teachers: Joyce Bischoff/Tom Freeman
Volunteer Help: Joyce Kunkle Jack Worton
Susan Noonan
Rm 214 Teachers: Carol Callaghan/Tom Doherty
Volunteer Help: Richard Chappel Suzanne Milazzo
Jane McKinstry Colette Watson
Rm 219 Teachers: Frank Czeiner/Linda McMeniman
Volunteer Help: Dick Burns
Roaming (laptop and John Dietz (first few weeks)
ID/password needs) Tom Keane (first several weeks)
Also: help thy neighbor!
© Spring 2011 Thomas P. Doherty
ALL Class site:
http://udel.edu/~tdoherty/DNAweb11s.pdf
for clickable links
19