Haven’t we always been doing genetic engineering for thousands of years? Didn’t we just call it selective breeding?
Yes we have been doing this with animals and plants (and even humans sometimes) with various techniques of selective breeding. We have selected the genes we want. But this has been a slow and uncertain business and perfection is not possible.
It would be possible, over many generations, for humans to breed for selection of intelligence. At the end of that we would undoubtedly have more intelligent offspring but they would not be optimal.
Intelligence is 80% genetic. There are around 500 genes involves in a polygene system. All of those genes would each have a number of alleles (maybe up to ten alleles each – I’m guessing). To get maximum intelligence the top allele would have to be selected for each one of those genes. The chances of doing that through selective breeding would be nigh on impossible – even if you went through a hundred generations of careful selective breeding.
With genetic engineering it would be possible to insert the optimum allele into each one of those genes. You could produce a human with the greatest possible intelligence in one single generation.
I think that is a bit different to anything we’ve done in the past. It is like comparing an old biplane with the Space Shuttle.
Genetic engineering has opened up new possibilities – not just for intelligence but all other aspects of human attributes and possibly even behaviours.