Replies

"Explain to us how recessive traits work in bacteria."

http://www.pnas.org/cgi/content/abstract/75/9/4470
September 1, 1978 | vol. 75 | no. 9 | 4470-4473
Copyright © 1978 by the National Academy of Sciences
Jos A. M. Van De Klundert, Peter H. Van Der Meide, PieterVan De Putte, and Leendert Bosch

Genetic analysis of a mutant of Escherichia coli resistant to the antibiotic mocimycin is presented. This resistance is due to alterations in both tuf genes coding for the elongation factor Tu. Mocimycin resistance is recessive. Bacteria carrying only one tuf gene from the resistant mutant are still mocimycin sensitive. If the mutant gene is the tufA gene, the sensitive cells can be made resistant through inactivation of the tufB gene by insertion of the bacteriophage Mu genome. Conditional mocimycin-resistant mutants can also be isolated when the tufB gene is altered by an amber or a temperature-sensitive mutation. When only the tufB allele from the original mocimycin-resistant mutant is present, inactivation of the wild-type tufA gene fails to give viable mocimycin-resistant progeny. We conclude that the tufA mutant allele codes for a functional mocimycin-resistant EF-Tu, whereas the mutant tufB gene does not code for a functional product.

Well, learn someting new. If a bacterium does have two or more genes for a trait, you still have dominance/recession. Full disclosure: I didn't know that.

However, sexual species except as noted routinely as part of the mechanism of reproduction will have multiple genes. It is part and parcel of the paired-chromosome diploid/haploid scheme of eukaryotic sex.

Bacteria will not reliably have multiple genes for a trait. They have duplication mutations, which is part of how genetic diversity happens, the very thing you are disputing. Also, they do this conjugation thing even among unrelated species. It doesn't typically reproduce individuals but it exchanges genetic material. You were clearly in your post referring to sexual dominance/regression from paired chromosomes. That was still inappropriate and wrong for bacteria.

And you don't dodge the emergence of new alleles this way unless you can show that every trait that has ever seemed to emerge as new is on a paired gene.