Hybrid Species

A History of Artificiallly Made Hybrid Species, Are We Playing God?

The sound of the phrase “hybrid species” may sound rather science fiction and unnatural. As if it’s something lab-based where scientists grow embryos in glass containers like in action movies.

However, hybrid species are more common than you would think, even in the wild. Various cross-species occur naturally through sexual reproduction. 

Stanford University has created a human-sheep hybrid, the second lab-made human hybrid species.

In the animal kingdom, hybridisation can occur between species of the same genus. An example would be the mule, an offspring between a female horse and a male donkey.

This species, although infertile, has helped mankind with migration throughout the years as they are easier to tame than both horses and donkeys.

Interestingly, there is some evidence that modern humans are a product of cross-species, Homo Sapiens used to interbreed with Homo Neanderthals, and due to this, we carry some percentage of Neanderthal DNA in our own. 

Plants had frequent interbreeding experiments to make it to the produce section. A species of banana is often bred with watermelons as they would produce seedless watermelons.

We have manipulated cross-species breeding for our own commercial al use, however, none of these included human hybrids with other animal species. Eerily, labs have started moving towards that direction for medical purposes. 

The first example of laboratory-made cross-species was from the discovery of the fluorescent gene of jellyfish. This discovery was so impactful that the scientists won the 2008 Noble Prize in Chemistry.

A properly deserved award as well, this gene has been transferred to other organism DNA as a marker to understand DNA expression.

Studies using the gene range from understanding the physiological changes in zebrafish at different pollution levels to targeting specific viral genes for vaccines to a whole-brain mapping of neuronal activity in depression.

Simple identification of a gene has allowed great advancements in the biomedical world, what more can cross-species offer us?

Human Hybrids

Hybrid Species

With the constant need for organ transplant, relying on organ donations alone has not been sufficient. In vitro cross-breeding may provide a solution for this.

Recently in 2018 Stanford University has created a human-sheep hybrid, the second lab-made human hybrid species.

The hybrid is less than 1% human, but this was enough to achieve the goal of the scientists, introducing human stem cells into sheep embryos

This marks the first time in history where human organ harvesting for medical use can be possible. 

Lead scientist Hiro Nakauchi states that in order for transplants to be successful the hybrid must be at least 1% human. However, the closer the hybrid is to human, the more ethical concerns emerged.

Biologist Pablo Ross from the University of California has shared his thoughts.

“Let’s say that if our results indicate that the human cells all go to the brain of the animal, then we may never carry this forward.” Explains Ross, fearing that there is a chance that a human hybrid may have developed human consciousness.

Still, he understands the aim of the research and the issue at hand, saying that even though such studies are controversial they “offer hope to people who are dying on a daily basis.”

Nakauchi is currently planning to launch a similar experiment in Japan, following the lifting of a ban that prohibited the growth of animal embryos with human cells.

He aims to inject stem cells into the embryo of a pig that has been mutated so it is unable to create a pancreas, reinsert it into a surrogate uterus, and examine whether the stem cells have transformed to human pancreas cells. He hopes that in the future this study will be able to provide pancreases to treat diseases like severe diabetes.

The Ethics

Hybrid Species

Although the technology behind this is astounding and has the potential to save thousands, ethical issues must be acknowledged when human cells are mixed in with animal embryos.

In 2007, a public poll was made by the Human Fertilisation and Embryology Authority (HFEA) on whether research on human hybrid embryos should be allowed. 61% of the public agreed while a quarter disagreed.

The HFEA have posted several arguments both pro and con. Both sides provide strong reasoning behind their point of view.


Arguments in favour of human hybrid embryos include:

  • Benefits of being able to harvest organs
  • Creatures are not being created, they are just cells
  • Avoids the use of human eggs in research


Arguments against human hybrid embryos include:

  • It is the start of a slippery slope that could lead to creating hybrid human/animal creatures capable of independent life
  • It is playing God
  • It is wrong to create embryos for disposal knowing they are partially human

The Verdict

Some religious factors also come into play when discussing ethics. And not for the first time, pig stem cells are often used in joint surgeries, this is of course against Islam where pigs are considered Haram. If stem cells are forbidden, obviously an entire organ would be worse.

Christianity concerns more towards the boundaries between animal and human.

Genesis 1-3 states that humans are unique. Beings are either human or animal and none in between. Creating hybrid species would simply break the boundary between what is human and what is an animal.

Buddhism believes that humans and animals are separate beings as humans have been blessed with superior spiritualism compared to animals.

Nonetheless, it is amazing how millions of years of evolution to turn apes to humans has been destroyed by a decade of science. The scientific revolution has increased with a rate so exponential that we are getting closer and closer to playing God.

Pro or con it appears that human-animal hybrid species will certainly be researched further, as nations are starting to convince themselves to allow human-animal embryo studies.

Medical research has provided us with powerful tools to alter biology for the benefit of mankind. However, the study of these hybrid species has arguably allowed playing God.

Obviously, the ability to harvest organs will save countless lives and is something spectacular, but will it be at the cost of our own morals?