Synthetic biology

The cloned sheep Dolly

We humans have long depended on pre-existing, naturally-occurring organisms that reproduce and provide us with more "copies" of useful creatures. The great diversity of living organisms on Earth has apparently been generated by processes of biological evolution taking place during the past few billion years.

I say "apparently" because we have very little information about the history of life on Earth. And we are now entering into a new era during which we will have amazing new technologies to facilitate the design and creation of new forms of life.

Humans have used artificial selection to produce many kinds of useful plants and animals and now genetic engineering allows precisely engineered genetic variants of existing organisms to be produced. Animals such a livestock can be artificially reproduced by cloning, using the existing DNA of an individual to take control of an egg cell and produce a new organism.

Craig Venter and his research team recently manufactured an entire bacterial chromosome and made what they call a "synthetic cell" by transplanting the artificial genome into an existing bacterial cell. Their goal is to design useful bacteria "from scratch" that can then be used by humans for many purposes and in ways that are not possible for naturally occurring bacteria.

What are the limits for such "synthetic biology"? In 1959 Richard Feynman gave a lecture in which he explained that "There's Plenty of Room at the Bottom". By 1959 it had been recognized that the genetic instructions for making all the proteins of a living organism are stored inside cells as a nanoscopic molecular code (DNA). What about other important parts of our biological selves? Are our memories and thoughts efficiently encoded and stored inside our brains or is there room for a synthetic biology program that might allow us to greatly miniaturize a human brain? Theoretically, how small could a human-like artificial intelligence be made?

The "wires" of a human brain are axons. In modern electrical engineering terms, the axons of neurons are pitifully inefficient devices for transmitting electrical signals. A typical axon is about 1000 nanometers in diameter and can conduct electrical pulses at a rate of about 100 per second. Current semiconductor manufacturing processes create circuit elements that are about 100 nanometers across and that can operate at electrical signal pulse rates in the megahertz range. Additional miniaturization might be possible and take us into the realm of true nanoelectronics.

We humans are taking our first steps into the age of nanotechnology. Who knows what might be possible given a few thousand years of continuing developments in electrical engineering and biology? Will it become possible to make artificial lifeforms that more efficiently accomplish what the human body can do?

It is fun to speculate about the the possible existence of human-like organisms on planets of distant star systems. What if some human-like species evolved millions of years ago and mastered nanotechnology long ago? What if an alien species created artificial life forms with nanoscale components rather than the microscale cellular components that are used in our bodies? It might be that interstellar travel is more conveniently accomplished by such artificial life forms than by biological organisms that are composed of cells.

What if such hypothetical artificial life forms visited Earth millions of years ago? What if such artificial life forms were here on Earth right now, watching us? Would we be able to detect them? How might they communicate with us, if they wanted to communicate? Would such visitors to Earth be content to communicate with us or might they long ago have been tempted to start tinkering with the genes of Earthly lifeforms? Such issues are explored in the collaboratively written story I'm not you. The story is under construction and additional collaborating authors are welcome.

Related reading: Molecular Communication