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If this ability is due to a genetic alteration, then this alteration will be passed on to each and everyone of its offspring since bacteria reproduce in a clonal fashion. Obviously, bacterial antibiotic resistance is achieved in many ways to include spontaneous genetic mutations that result in new traits or functions that were not present in previous generations of that bacterial group or species.Some argue that these changes are not "evolutionary" since they do not really increase the information content of the DNA within that bacterium. Carl Wieland (An Australian Medical Doctor): This misconception [about antibiotic resistance and evolution] may be partly due to the fact that even many science graduates believe that the mechanism of antibiotic resistance involves the acquisition of new DNA information by accidental mutations... Loss of control over an enzyme's production can engender antibiotic resistance.The same limitations seem to be present when it comes other functions that exist at a similar level of functional complexity (i.e., having a similar minimum sequence size and specificity of amino acid residue arrangement for a minimal degree of selectable function).

Mutation can cause the loss of control of its production, so much greater amounts are produced, and a bacterium producing large quantities of penicillinase will survive when placed in a solution containing penicillin, whereas those producing lesser amounts will not.

The information for producing this complicated chemical was, however, already present He is also correct in stating that the information for producing the penicillinase enzyme does not spontaneously evolve in those bacteria that are able to produce it, but was already present either through vertical transmission from the previous generation or via horizontal transmission through the action of plasmids or other methods of DNA transfer between bacteria.

Also, although no one has ever observed the de novo evolution of a penicillinase enzyme, evolutionary scientists present evidence for the original evolution of penicillinase from existing bacterial genes - but this still remains hypothetical until such proposed evolutionary pathways can be demonstrated in real time.there are many similarities, especially when one considers the three-dimensional structures and active sites between homologous sequences that are supposed to be the most likely precursor proteins to penicillinase (appendix), but there might be a few functionally significant neutral gaps between them. Ultimately, if the crossing of such evolutionary paths between these two enzymes is truly an easy process, as many claim it is, then why is Similar evolutionary limits have been found with other single protein enzymes - like lactase evolution experiments showing "limited evolutionary potential" in mutant forms of K12 E. It seems like the average distance of selectable lactase sequences in sequence space is quite significant given the lack of lactase evolution over the course of many tens of thousands of generations in a lactose rich environment.

In the proposed evolutionary pathway from a DD-peptidase to a beta-lactamase, each and every step needs to increase beta-lactamase activity in a selectable way or there will be a neutral or even detrimental block in the pathway.

As additional support for this statement, consider that bacteria recovered from historical isolation have been found to be resistant to modern antibiotics.

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