Re: Is it possible to genetically engineer a new lifeform?

Hi Matt,

You ask whether it's possible to genetically engineer a new life form. The answer to this depends on what you mean by 'a new life form'. Geneticists regularly take genes from one organism and put them into another. This is known as transgenics and usually involves only one or a few genes with a very specific function. A transgenic organism can be considered to be a new 'life form', since it contains a unique set of genes (referred to as its genome) that didn't exist before. However, in every respect except one it will resemble the original organism into which the new gene was introduced.

For example if you were to take the gene for growth hormone from a pig and put it into a mouse the resulting transgenic animal would look very much like a mouse, although it may have altered growth patterns. The precise effect on growth would be difficult to predict without performing the experiment, but you would not expect the transgenic animal to look like a pig.

This all assumes that the newly introduced gene only has a single effect on the organism it's been put into, but some genes are known to have several different effects on the organisms that carry them. For example, in humans both eye colour and hair colour are affected by the same gene so that altering the gene for one will also have an effect on the other. The newly introduced gene may also have effects in the recipient which it did not have in the donor, which is one of the reasons why so many people think transgenics should be banned.

To engineer an organism with a genuinely unique appearance using transgenics, it would be necessary to combine genes from a large number of sources. Since it's difficult to predict the results of introducing a single new gene, imagine how much harder it would be to predict the outcome of combining genes from many different organisms.

All life forms consist of vast and complex sets of interacting molecules. These molecules are products of different genes, however these genes have not evolved in isolation but in the context of the entire genome. If we were to attempt to create a new life form by taking parts of the genomes of several different organisms and combining them in new ways, it's extremely unlikely that this new combination of genes would give rise to a viable living organism. We understand very little about how genes interact to form living organisms. Perhaps in the future, as we learn more about this process, the creation of new transgenic life forms will become easier. But this is likely to be a long way off, and it may be that for other reasons society decides this is not a desirable thing to do.

Transgenics can only use genes which already exist in nature. It's the way these genes are combined which is unique, not the genes themselves. At present it isn't possible to make new functioning genes from scratch in the laboratory (although according to a recent report this may not be far away), but there is one other alternative to transgenics which can be used to create 'new life forms'. This is called mutagenesis.

Mutagenesis involves the use of radiation, chemicals or other processes to deliberately causes changes (mutations) in a gene. Mutations almost always cause a gene to stop working, or work less well, but very occasionally a mutation will allow the gene to continue working but in a slightly different way. Naturally occurring mutations are the fuel for evolution by natural selection. In the laboratory, deliberate mutations can be used to generate new forms of genes which can be combined with transgenics to create new varieties of organisms. However, as with transgenics, this is only practical for very small numbers of genes.

I hope this answers some of your questions about genetic engineering. This is a difficult subject, but an interesting one, and I'm glad you've decided to find out more about it. For lots more information check out New Scientist's excellent list of genetics websites.

Good luck!

Rob Cruickshank