Scientists create first human-monkey hybrid

Never let me go: The team also created the first human-pig embryo in 2017.

Should animals ever be part-human? Faced by a deadly shortage in human organs for life-saving operations, our only hope may be animals with human DNA. But there are serious ethical concerns.

In an unnerving storyline lifted straight from science fiction, Spanish scientists have successfully created the world’s first human-monkey hybrid in a laboratory.

The experiment was highly controversial and would be illegal in most countries, so it was conducted in China where the team was able to avoid laws covering experiments on animals.

Juan Carlos Izpisua, who led the team, had already created a human-pig hybrid in 2017. Since then, his team has experimented with human-sheep and human-mouse hybrids using a technique that injects human stem cells — capable of creating any type of tissue — into animal embryos to create human-animal chimeras.

Many experts are saying that this latest human-monkey hybrid has taken the science a huge — and chilling — step forward.

Though the experiment was deliberately ended before the creature was born, the scientists claim that the human-monkey hybrid could have gone on to be born and to live.

So, if the hybrid was never going to be allowed to live, why create this “unnatural” hybrid in the first place?

The scientists say they want to create organs for live-saving operations for humans. Every day, 20 people die waiting for an organ transplant. Across the US and UK alone, there are over 150,000 people on waiting lists.

Human-monkey hybrids, with human organs grown inside their bodies, could help treat this major global problem.

Several countries have softened their laws to allow faster progress.

In March, Japan lifted a ban on allowing chimeras to be born. And in April, scientists in China claimed they had introduced a human brain gene into monkeys, reporting that it gave the animals better short-term memory and shorter reaction times.

But some scientists are worried. Ángel Raya, in Spanish newspaper El País, argues, “What happens if the stem cells escape and form human neurons in the brain of the animal? Would it have consciousness?”

Estrella Nunez, on the research team, insists that mechanisms are in place to ensure that if human cells migrate to the brain, they will self-destruct.

Frankenstein’s monkey?

This is very exciting, say some. Scientists could save lives and stop the black market in body parts. If we could generate and transplant organs at will, imagine how much longer we could live and how many diseases we could cure.

Science gone chillingly mad, say others. Have these scientists ever watched an episode of Doctor Who or seen Planet of the Apes? This research is far from guaranteed to work: even if it does, the creatures produced may be conscious, thinking beings who feel pain and suffer. We are not superior to other animals, and we have no right to create them for our selfish interests.

You Decide

  1. Would you accept a life-saving organ which was grown inside an animal?
  2. Should scientists be allowed to create chimeras for experiments?


  1. Think about other human-animal combinations that might be created by scientists. List three of your ideas, noting the potential benefits of each one.
  2. Write a one-page story about a human-animal hybrid experiment gone wrong. Write it from the point of view of the scientist.

Some People Say...

“The labours of men of genius […] scarcely ever fail in ultimately turning to the solid advantage of man.”

Mary Shelley (1797-1851), author of Frankenstein

What do you think?

Q & A

What do we know?
Scientists have been creating partly human chimeras for years. Researchers use rats with human tumors to study cancer, and mice with human immune systems for AIDS research. What’s new is putting human stem cells into the embryos of other animals at an early stage of embryonic development.
What do we not know?
It is unclear how long it will take scientists to create a human-monkey chimera that will actually be born. The evolutionary distance between humans and monkeys spans 30 to 40 million years, so it is unclear if it is even possible given that creating a hybrid of two, closer related species (like a mouse-rat chimera) is quite low.

Word Watch

Illegal in most countries
Many countries take an extremely restrictive approach to the creation of chimeric embryos. In Spain, for example, research of this type is limited to the investigation of deadly diseases.
Human stem cells
Special human cells that have the ability to develop into many different types of cells, from muscle cells to brain cells. They can also help to repair damaged tissue. One day, scientists hope to treat Alzheimer’s disease and paralysis using stem cell-based therapies.
An embryo is a small cluster of fertilised cells that will develop into a foetus and, eventually, into a baby. Whether or not an embryo is be defined as a living being, or granted the same rights as a live baby, is a hotly debated and highly emotional issue.
In Greek mythology, the Chimera was a fire-breathing creature, usually depicted as having the head of a lion, the body of a goat and a snake for a tail. In medicine, the term refers to an animal, plant or human, which is made up of more than one organism.
According to the NHS, over 400 people died in the UK last year, awaiting an organ donation.
Black market
Illegal buying and selling.

PDF Download

Please click on "Print view" at the top of the page to see a print friendly version of the article.