A new relationship with animals, nature and each other.

What’s Human? What’s Animal?

The not-so-brave new world of chimeras in the lab

Is it OK to inject human cells into other animals like laboratory mice and create hybrids?

A few weeks ago, scientists announced they had mixed human DNA into cows in order to make them produce human breast milk. (One justification for this was that it would help children in underdeveloped countries.)

But human-other chimeras (half one species, half another) have long been a holy grail of certain branches of science.

And now a group of ethicists are urging that medical research on animals that contain genetic material from humans should be tightly regulated.

These chimeras are not so much to do with creating oddities like frogs with human heads or monkeys with human vocal chords (although who knows what people in labs might do if they could), but rather to show that stem cells from hybrids could lead perhaps to new treatments for human ailments.

One of the members of the ethics panel noted that:

“If you start putting very large numbers of human brain cells into primates, suddenly you might transform primates into something that has some of the capacities that we regard as distinctively human – speech or other ways of being able to manipulate or relate to a human.” Tom Baldwin, University of York.

To blur the line between a mouse and a zebra is one thing; to produce something that’s part-mouse part-human is quite another and raises serious red flags in the world of ethics.

So, what’s at the heart of this concern? Is it that we might do harm to other kinds of animals? Or is it more that this has the potential to drive a wedge into the notion that we humans are a species apart – a species fundamentally different from and superior to other animals?

In 2005, Sen. Sam Brownback (R-Kansas) introduced a “Human Chimera Prohibition Act.” Brownback said the bill would prevent experiments that would “blur the lines between human and animal, male and female, parent and child, and one individual and another individual.” The legislation did not pass, but the U.S. National Council of Churches supported it, saying that it opposed “the creation of chimeras or any experimentation that might lead to an intermediary human/animal species.”

“Where do we draw the line between the human and the nonhuman? Mixing human and animal genes could create confusion, inviting moral chaos.” Ted Peters, Professor of Systematic Theology at Pacific Lutheran Theological Seminary.

The new debate, along with the call for greater regulation of experiments that combine the cells of humans and other animals, expands on one of the fundamental ethical problems raised by experimentation on animals: If we argue that it’s OK to experiment on other animals because they are not like us, then what value to humans can there be in such experiments? If, on the other hand, we justify these experiments on the basis that there are important similarities between ourselves and the animals we’re using, then how can it be ethical to conduct these experiments on them?

In a separate post, we offer some insight from psychologists who argue that the need for us humans to see ourselves as more than simply “animal” stems from our awareness (and basic terror) of our own mortality. They explore the notion that much of our culture, including art, religion and politics, is an attempt to tell ourselves that we are not animals and not subject to mortality.

What do you say? Do you think it’s OK to mix human cells, DNA, etc. with that of other animals? Where do you draw the line. Tell us in a comment or on Facebook.