Procaryotes. (I gather that's some kind of Brit spelling.)
Highlights:
Bacterial lateral transfers are known as parasexuality.
Beside the exchange of genetic information via plasmid, the cell is able to gain valuable information by taking up DNA. These mechanisms are generally referred to as parasexuality. In contrast to the sexuality of eucaryotic cells, where the genetic information of both partners is equal and where both genomes contribute equally to the species’ progeny, in parasexuality, the information of one partner is enhanced at the expense of the other’s.This isn't even a sharing of information, really. It's more like the stealing of same. What one gains, another actually loses.
It is mostly the extra-chromosomal plasmids involved in this process that create the appearance of polyploidy:
Bacteria have an extensive array of restriction endonucleases specific for this purpose at their disposal. The bacterial genome is mostly haploid, but the information stored in the plasmids has to be regarded as polyploid, since the cells contain usually several copies of the same type of plasmid.This is the data set that someone is Googling up a little bit at a time to prove that no new information is ever created, nor does it need to be because bacteria are diploid.
His problem remains: Explain how recessive traits work in a bacterial colony descended from a single individual.