Transcript Lecture 8 - Michigan State University

Lecture 8: Manipulation of
Development, Aging and Death
Now playing:
Weird Al Yankovic
“I
Think I’m a Clone, Now”
Goals:
1. Define fertilization, conception, cleavage,
implantation, embryo, fetal period, birth,
maturation, aging & death.
2. Understand ethical issues of abortion and euthanasia:
naturalism, deism, theism, pantheism & nihilism.
3. Apply topics to life, science & heath care.
Assignment:
Read: chapter 15, 38 (In B/C 26)
Websites: http://www.religioustolerance.org/euthanas.htm
http://www.religioustolerance.org/abortion.htm
http://www.religioustolerance.org/cloning.htm
http://www.religioustolerance.org/emb_rese.htm
http://prorev.com/genetic.htm
http://www.indiana.edu/~engs/cbook/chap2.html
http://fertilethoughts.net/faq/asrm/screen.html
http://www.leaderu.com/orgs/narth/1995papers/satinover.html
http://www.pbs.org/newshour/forum/april98/iq07.html
http://hem.passagen.se/nicb/god_ethics.htm
What are some of the scientific, ethical, moral
and societal challenges associated with
Fertilization, Development, Aging and Death?
Birth Control, fertilization, abortion, aborted fetal
products, stem cells, manipulation of life,
manipulation of death…
Key Terms
Cloned human embryo
Embryonic stem cell
Blastula, Blastocyst
Pluripotent
Karyotype
How does cloning work:
– Where does the egg come from
– Where does the DNA come from
– How many copies of each chromosome
Evidence of a Pluripotent Human Embryonic Stem
Cell Line Derived from a Cloned Blastocyst
Woo Suk Hwang et al.
1 College of Veterinary Medicine, Seoul National University, Seoul 151-742, Korea;
• Somatic cell nuclear transfer.
• Pluripotent embryonic stem cell line
• Cloned human blastocyst.
– Capable of differentiating into embryoid bodies
– Containing cell derivatives from all three
embryonic germ layers
• Capable of continuous proliferation for >70
passages
• Cells maintain normal karyotypes
Fertilization- The Big Event
Cortical Granules
Acrosome
Mitochondria
Egg
Sperm
Tail
Egg
Corona Radiata
Nucleic Acid: DNA
Zona Pellucida
inner cell mass
oviduct
uterus
FERTILIZATION
ovary
IMPLANTATION
endometrium
Fig. 39.21a, p. 666
Trophoblast
(surface layer
of cells of the
blastoyst)
Endometrium
Start of
Start of
amniotic embryonic disk
cavity
Blastocoel
inner cell mass
Start of yolk sac
Uterine cavity
DAYS 6-7
DAYS 10-11
Shorion
Shorionic
villi
Chorionic
cavity
Blood-filled spaces
Smniotic
cavity
Start of chorionic cavity
Connecting
stalk
yolk sac
DAY 14
DAY 12
Nucleus of a
diploid (2n)
Reproductive cell
with two pairs of
homologous
chromosomes
Meiosis
OR
Possible alignments
of the two
homologous
chromosomes
during
metaphase I of
meiosis
A
A a
a
A
A a
a
B
B b
b
b
b B
B
The resulting
alignments
at metaphase II:
A
A
a
a
A
A
a
a
B
B
b
b
b
b
B
B
allelic combinations
possible in gametes:
B
A
B
A
1/4 AB
b
a
b
a
1/4 ab
b
A
b
A
1/4 Ab
B
a
B
a
1/4 aB
Fig. 10.8, p. 158
FERTILIZATION
Oviduct
Ovary
OVULATION
Uterus
Opening of
cervix
Zona pellucida
Vagina
Follicle cell
Granules in cortex
of cytoplasm
Sperm
enter
vagina
Nuclei fuse
Fetal Period
Fetus: third month of human development until birth
Growth
Development
Increase in number, size and volume of cells
Emergence of specialized, distinct body parts,
according to genetic programming and the
environment of the uterus
Age of survivability
14 weeks
Age at which a fetus can survive outside
the mother: currently 19 weeks
5 months
6 months
Facts about American Abortions
Reasons for Aborting:
• 92% of all American abortions are for “social
engineering” or “quality of life” reasons.
• 8% of all American abortions are for the so called
“hard cases”: rape, incest, health of the baby
or threat to the health of the mother.
Source: The Allan Guttmacher Institute
When should abortion be legal in America?
Source: Gallup/ CNN/ USA Today Jan, 2003
• Abortion should be illegal in all cases = 18%
• Abortion should be legal only to save the life of the mother = 85%
• Abortion should be legal to save the life of the mother only in cases
of rape or incest = 77%
• Abortion should generally be legal during the first trimester?
66% Yes
29% No
• Abortion should generally be legal during the second trimester?
25% Yes
68% No
• Abortion should be legal at anytime during a woman’s pregnancy
for any reason = 10%
Birth
Birth
What is human?
1:18,000 births = Anencephalous
(born without a brain)
-GENES
-CELL LINES
-Stem Cells
-BODY PARTS
Commercialization of human parts
“Participatory Evolution”
A Banal Avarice:
In private industry’s hands with a
motive to profit where will we
stop?
• Abortion
• Testing
Human
• Marketing human genes?
Morality
• Selling aborted products?
• Wall Street trading in body parts
from cloned anencephalic babies?
$
Population Control Lobby
Because teens in other
developed countries receive
more education about
sexuality and have more
access to contraception and
family planning services, they
have much lower rates of
pregnancy and abortion. For
example, in the Netherlands,
where teenage sexual activity
is about the same as in the
U.S., pregnancy rates are only
one-ninth those of the United
States.
What about birth defects?
Morals, ethics & $…
With the capacity to fix them, what
about those who can’t afford the fix?
If life science can market 20,000 tests, who wouldn’t want them?
What happens to evolution when man starts manipulating life/death?
Trisomy 21 carriers = apparently never get cancer
Catastrophe
survivors?
Frequency
Of
Types
Birth Defect Types
Human Population less risk of cancer?
In the 1930’s and 40’s, we convinced ourselves to sterilize those with defects!
How do you know
what is right?
•Is this procedure immoral, banal
avarice, participatory evolution or
responsible health care?
•Where does right and wrong
come from in health care & who
decides?
•Does everyone everywhere
have access to this technology;
why or why not?
•Who controls the technology,
and how was control awarded?
•Follow the $ & the folks that profit?
Bioethics
Destroying Embryos is the Basis of the
Ethical Debate
Questions:
1.
2.
3.
4.
What is the moral status of the developing
embryo
Is this simply tissue or is it something
more?
Is this a twin? The genetic make up is
identical
What is the purpose?
– Making donor tissue?
– Making a baby?
5.
Is regenerative medicine ethical?
Maturation
Human
-Burns
-Scars
} Regeneration
Lizards and salamanders can
regenerate limbs and tails
…perfectly!
…but imperfect
HOW?????
Death
• Definition
• Ethics
Definition of Death
1. Absence of life
2. Lack of sensation
3. No growth, reproduction
or metabolism
4. Without normal
function
{
Brain waves
Sinus rhythm
5. Genetic inability to function
6. Lacking the “spirit” or “essential spark of life”
Aging
Environmental resistance
Master genes
Programmed death
-master genes = fountain of youth
Free radicals and superoxide
dismutase (SOD)
Environmental resistance contributes to aging:
-Connective tissue and somatic cells
decline in regeneration rates
•Skin elasticity
•Wrinkles
•Joints
Euthanasia
What’s your stand?
In the Greek language, eu means "good" and thanatos
means "death". The meaning of the word is "the
intentional termination of life by another at the explicit
request of the person who dies."
•Some terminally ill patients are in severe pain
and experience an intolerably poor quality of life
•The cost of keeping terminal patients
alive diverts money, medicine and
caregivers’ availability to non-terminal
patients.
•The financial burden for patients’ care
upon their families may be prohibitive of
adequate care
Contemporary
moral standards
Euthanasia
Scientific
ideology
Master genes
When secondary sex characteristics
begin to develop, signals are sent from
neurosecretory cells
Master genes turn on
and you’re programmed
to die
Are master genes the
key to the fountain of
youth?
Programmed death
Free radicals and Superoxide Dismutase (SOD)
Age spots
Memory Loss
Cataracts
Arthritis
Alzheimer's disease
When a chemical bond is broken: the electrons can stay together (both go to one
of the atoms and the other atom gets none)
•ion
•electrically charged (the atom with the electrons is negatively charged
and the one without the electrons is positively charged) and generally stay
together or they can split up (one electron goes to each atom).
•free radicals (molecules with an unpaired electron).
•highly energetic and seek out other electrons with
which to pair and steal electrons in the process
Antioxidants (also known as free radical scavengers) such as
Vitamin E, Vitamin C, beta-Carotene and Selenium function by
offering easy electron targets for free radicals.
Ethics & Metaphysical Beliefs: Worldviews
1. Naturalism
2. Deism
3. Theism
4. Pantheism
5. Nihilism
Some basic philosophical beliefs...
1. Closed system
Naturalism
2. materialism
5 senses, atomic particle nature of all things
3. we don’t exist as immaterial selves, either
mental or spiritual, that control
behavior--we are only matter
4. Life = blind chance, everything we are and
do is included in the material
continuum whose most basic elements
are those described by physics
5. Life = no purpose
6. Man’s conscience = physiological/psychological response
-- knowledge about what exists and about
how things work is best achieved through
the sciences, not personal revelation or
religious instruction
When we die, what's next is nothing;
death is an abyss, a black hole, the end of
experience; it is eternal nothingness, the
permanent extinction of being
Deism
1. design is found throughout the known
universe and this realization brings Deists to a
sound belief in a Designer or God.
2. God created the universe
3. God did stuff and then left it to run on its own.
4. “The Blind Watchmaker”
5. Anti-supernaturalism: Miracles do not occur
6. “the Bible, though it contained important truths, was
not divinely inspired; many important Christian
theological tenets -- the divinity of Christ, the
doctrine of the Trinity, and the theory of
atonement for sins -- were the results of
superstition or invention and had to be rejected.”
Theism
1. Design found throughout the known universe and this
realization brings Theists to a sound belief in a God.
2. Open system or Universe
3. God was active creator and sustains current life and the Cosmos
4. Miracles occur, but are not disruptions in nature they are
synchrony in nature.
5. God communicates with man; moral realism: what is right and
wrong is independent of what any person thinks is right and
wrong.
6. Man is unique in creation
Pantheism
1. universe = ever-changing totality of being,
past, present and future; self-creating, selforganizing, and inexhaustibly diverse
2. All matter, energy, and life are an interconnected unity of which
people are an inseparable part
3. People should cherish, revere and preserve in all life’s
magnificent beauty and diversity (human and non-human)
4. moral realism: believe it is an objective fact that some kinds of
actions are ethically right and others wrong, and what is right
and wrong is independent of what any person thinks is right
and wrong.
5. God is identical with the real world. God is all and all is God. God
does not transcend reality but is imminent in reality, or
rather, all reality is in God.
Death is a return to nature of our elements. Our
actions, our ideas and memories of us live on in
the world, according to what we do in our lives.
Nihilism
1. The belief that all values are baseless and that
nothing can be known or communicated
2. “Death is nothing.”
3. “There is no God.”
4. “I could be wrong.”
Just tell me what a
disordered universe would
look like. I can't imagine it
would be any different than
this one
Life is pleasant. Death is
peaceful. It's the transition
that's troublesome.
--Isaac Asimov (1920-1992)
Russian/American Science-Fiction Author,
awarded 7 Hugo Awards, 3 Nebula Awards
(among others), 14 honorary doctorates, 1997
Science Fiction and Fantasy Hall of Fame
inductee
All things are connected like the blood which unites one family. Whatever befalls
the earth befalls the sons of earth. Humans did not weave the web of life. He is
merely a strand of it. Whatever he does to the web he does to himself.
All there is, is the Cosmos.
All conditioned things are subject to decay. Strive with
diligence.
God is dead and therefore, man is free.
There are innumerable definitions of God because His
manifestations are innumerable.
There are only two ways to live your life. One is as
though nothing is a miracle. The other is as though
everything is a miracle.
Death is nothing else but going home to God, the bond of
love will be unbroken for all eternity.
I am the way, the truth and the life, no one comes
to the Father but through me.
All things are connected like the blood which unites one family. Whatever befalls
the earth befalls the sons of earth. Humans did not weave the web of life. He is
merely a strand of it. Whatever he does to the web he does to himself. –
Chief Seattle
All there is, is the Cosmos. –Karl Sagan
All conditioned things are subject to decay. Strive with diligence. -Buddha
God is dead and therefore, man is free. -- Neitzche
There are innumerable definitions of God because His manifestations are innumerable. -Mahatma Gandhi
There are only two ways to live your life. One is as though nothing is
a miracle. The other is as though everything is a miracle. -- Albert
Einstein
Death is nothing else but going home to God, the bond of love will be
unbroken for all eternity. -- Mother Teresa
I am the way, the truth and the life, no one comes to the Father but
through me. –Jesus Christ