Sunday, 1 January 2017

Modifying Humans For Life in Space

Does life need an atmosphere like Earth's?

Not always, it seems. Simple life can survive in the harshest of conditions. Can humans be engineered to survive in such conditions too? To find out we need to understand how simple life-forms manage it, and consider any existing evidence of life surviving in space.

Panspermia is the theory that life is spread through the universe by debris thrown into space by violent impacts. Some of that debris, containing hardy microbes similar perhaps to Earth's extremophiles, eventually lands on a suitable planet, and evolution begins. This theory becomes highly plausible when we consider that there are some Earth microbes that can indeed survive in the harsh environment of space. It seems that life that can survive a long exposure to deep space may well be extremely common.

Chroococcidiopsis: an extremophile with the potential to help terraform Mars

But could complex, and even intelligent, life be engineered to survive in the extreme conditions of space?

It certainly seems possible, and there is a complex creature on Earth that can survive in space, at least for while: Tardigrades. These tiny animals are found everywhere, from mountain tops to the depths of the oceans, and from the tropics to the Antarctic, and are the toughest multicellular organisms known. They have remarkable survival abilities. The can withstand temperatures from -272 Celsius to 150 Celsius, pressure up to six times that of the deepest oceans, exposure to radiation hundreds of times higher than the lethal dose for humans, and they can be frozen for decades and still live on and reproduce after thawing.

And they can survive in the vacuum of space, the only know animal with that ability.

A Tardigrade, the toughest known animal. It is almost impossible to kill.

Why did such a resilient creature evolve on our planet? Could it be used to engineer a more complex and possibly intelligent lifeform, or even to modify humans, to live in extreme environments?

I think so.

Alongside all the usual research that will enable humans to embark on interstellar colonisation (new propulsion systems, generation ship design, closed life support mechanisms etc.) research into how humans could be re-engineered to survive in harsher environments is also essential.

Perhaps on a generation ship there could be a genetically modified element to the crew that could look after the 'standard' humans that are forced to remain in their rotating Earth-like bubble at the centre of the ship. The modified crew would be able to survive for long periods in minimal gravity, and with a limited atmosphere. They would look after the ship and ensure that the standard humans are in good shape to land at the destination world. They would breed as the standard humans would, replenishing their numbers as the centuries of the voyage rolled by.

The genetic engineering could even extend beyond just the physical and tune psychology and intelligence to match the intended function of the modified human, rendering them almost perfectly adapted to their roles.

All of this would ideally be monitored and controlled by an immortal crew, another set of engineered humans that would oversee the whole voyage, and ensure the continuation of the thought and culture of the standard humans whose descendants would one day colonise the destination planet (see my earlier article 'Immortal Travellers').

As well as the scientific challenges to modifying humans in such a way, there are ethical challenges too. And the ethical challenges may end up becoming the hardest to overcome. But such challenges must be faced and surmounted if we are to have the greatest chance of surviving long enough to spread our species out amongst the stars.

Experimenting on human embryos and allowing them to grow to maturity to see the effects of genetic modification would be unacceptable, and also very time-consuming. Instead, sophisticated computer simulations need to be developed to give genetic scientists the ability to design such humans, and test them in virtual environments. Only when we are sure we have developed a new breed of human perfectly adapted, both physically and mentally, to the desired environment, should actual living versions be grown.

Computer programming languages already exist that can be used to add new 'features' to DNA. Such languages are in the early stages of development and use, but in the near future, when such languages are used in conjuction with a virtual simulations of the results, we will have the ability to design a perfectly adapted crew for deep space travel. With the constant improvements in computing power the systems required for this, and the software to run on them, such facilities may well be available in just a few decades.

A neanderthal family

Forty-thousand years ago there were four species of humans on Earth. For almost the Last 20,000 years our species, homo sapiens, has been the only one.

Perhaps that is about to change?