HYBRID HUMANS: WHAT'S AT STAKE? Dennis M. Sullivan, MD, MA (Ethics) Director, Center for Bioethics Cedarville University Center Web Site: www.cedarville.edu/bioethics E-mail: [email protected]
Feb 23, 2016
HYBRID HUMANS:
WHAT'S AT STAKE?
Dennis M. Sullivan, MD, MA (Ethics)Director, Center for Bioethics
Cedarville UniversityCenter Web Site: www.cedarville.edu/bioethics
E-mail: [email protected]
OBJECTIVES
To survey new biotechnologies that cross species barriers, especially as it relates to human beings
To examine the bioethical questions
raised by such research
To attempt to delineate a “bright line” between the ethical and the unethical
WHAT IS A HYBRID?
Linguistics: the process of one language variety blending with another variety.
Automobiles: the alteration of a vehicle to run on two fuel sources.
Chemistry: the mixing of atomic orbitals to form new orbitals suitable for bonding.
Molecular Biology: the process of joining two complementary strands of DNA.
Genetics: combining different varieties or species of organisms.
“Look at him – So high and mighty with his fancy hybrid!!”
CHIMERA: THE ULTIMATE HYBRID
Homer's Iliad:– “A thing of immortal make, not human,
lion-fronted and snake behind, a goat in the middle, and snorting out the breath of the terrible flame of bright fire.”
– Finally defeated by Bellerophon, with the help of Pegasus, at the command of King Iobates of Lycia. Since Pegasus could fly, Bellerophon shot the Chimera from the air, safe from her heads and breath.
HYBRIDS IN THE MEDIA
Australian artist Patricia Piccinini's concept of what human-animal hybrids might look like
Maybe I'm just a duck, but I'mhuman.— Donald Duck, Early to Bed
-- I am not an animal! Hear me?I'm not an animal. Well... okay,maybe I am kind of an animal,I'm a duck. And I don't wearpants. But I talk and live in ahouse, so you know whatI had in mind.-- Duckman
MIXING IT UP:WHERE HAVE
WE BEEN?
TRANSPLANTATION:
Autotransplantation (e.g., skin grafts) Allotransplantation:– Kidney transplants– Bone marrow transplants– Adult stem cells (auto- or allo-)
Xenotransplantation– Crossing the species barrier– Such cells, tissues or organs: xenografts– Examples: porcine valves, baboon heart,
bovine pancreatic tissue, temporary porcine skin grafts
ETHICAL QUESTIONS
Natural Law concerns (minimal)
Utilitarian concerns–May be risky (primarily related to
rejection)– Animal to human disease transmission
Animal rights
MIXING IT UP A BIT MORE:WHERE ARE
WE GOING?
HUMAN/ANIMAL TRANSGENICS
Transgenic animals:– DNA from another species inserted into
their genome– Transgenic sheep and goats: express
foreign proteins in their milk– Transgenic chickens: synthesize human
proteins in the “white” of their eggs.
TRANSGENIC FISH:
A MEDICALLY USEFUL EXAMPLE:
Normal mice: resistant to human polio virus –Why? – Lack cell-surface molecule that serves
as the receptor for the virus Transgenic Mice:– Express the human gene for the polio
virus receptor– Therefore: can be infected by polio virus
and even develop paralysis– Inexpensive, easily-manipulated model
for studying the disease
MIXING IT UP STILL FURTHER:
ARE YOU NERVOUS YET?
TRANSGENICS: HOW MUCH IS TOO MUCH?
Transgenic pigs:– So far just a theory– “Knock out” the genes that code for two
key molecules that trigger rejection– Ultimate goal: genetically engineered
pigs as a source for transplantable organs for humans
Mouse-Human Chimera:– Human stem cells put into brains of fetal
mice– Human cells divide and grow in mouse
brains–Model for studying human neural
diseases
THE ETHICS OF TRANSGENIC PIGS:
Natural Law Concerns–More substantial– Seems “unnatural”
Biblical Concerns– Proscription of bestiality– Exodus 22:19; Leviticus 18:23– Leviticus 20:15-16; Deuteronomy 27:21– But these all deal with sexual relations
But: None of the examples citedcan pass altered genes to their offspring
MIXING IT UP: WHAT ARE
THE LIMITS?
SB 243: OHIO BAN ON ANIMAL-HUMAN HYBRIDS
Passed in 2010 by Ohio Senate Bans the following: – Creation of a human embryo where it is
uncertain whether the human embryo is a member of the species homo sapiens;
– A hybrid human-animal embryo produced by fertilizing a human egg with a nonhuman sperm;
– A hybrid human-animal embryo produced by fertilizing a nonhuman egg with a human sperm;
– An embryo produced by introducing a nonhuman nucleus into a human egg;
SB 243 (CONTINUED)
Bans:– An embryo produced by introducing a
human nucleus into a nonhuman egg;– An embryo containing chromosomes
from both a human and a nonhuman life form;
– A nonhuman life form engineered with the intention of generating functional human gametes within the body of a nonhuman life form;
– A nonhuman life form engineered such that it contains a human brain or a brain derived wholly from human neural tissues.
WHY IS ALL THIS WRONG?
God created species to reproduce “after their kind” (Gen. 1:24)
Humankind is made in the image of God (Gen. 1:26-28)
Human dignity is grounded in a strong sense of human nature
The ultimate in technological hubris:– “Transhumanism”– The “human re-engineering project”– Gen. 1:31 inverted
C. S. LEWIS (THE ABOLITION OF MAN):
“Human nature will be the last part of Nature to surrender to Man. The battle will then be won … But who, precisely, will have won it?”
QUESTIONS?
HYBRID HUMANS:
WHAT'S AT STAKE?
Dennis M. Sullivan, MD, MA (Ethics)Director, Center for Bioethics
Cedarville UniversityCenter Web Site: www.cedarville.edu/bioethics
E-mail: [email protected]