Zachriel
Posts: 2723
Joined: Sep. 2006
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DaveScot blogs, Another Icon of Evolution Bites the Dust - Antibiotic Resistance. And I thought IDers had no problem with microevolution. In any case, to support his assertion, DaveScot cites Alekshun & Levy. This Alekshun & Levy:
| Quote (Alekshun @ Levy) | | clinical improvements and widespread use and misuse of antibiotics have pushed evolution, allowing normally non-pathogenic strains to become infectious disease threats to human health. |
These are the quotes from Alekshun & Levy's latest journal article that DaveScot indicated were pertinent.
| Quote (Alekshun @ Levy) | | Although classically attributed to chromosomal mutations, resistance is most commonly associated with extrachromosomal elements acquired from other bacteria in the environment |
Most, not all. The classic Lederberg lab experiment, repeated daily in universities around the world, starts with clonal bacteria, and demonstrates that occasional genetic mutations result in antibiotic resistance, and that such mutations occur whether the bacteria are exposed to antibiotics or not. That is, the mutations are random with respect to the environment. It's also known that bacteria exchange genes through lateral transfer. The success of these bacteria is predictably dependent on environmental selection.
| Quote (Alekshun @ Levy) | | The means that microbes use to evade antibiotics certainly predate and outnumber the therapeutic interventions themselves. |
That's expected as most antibiotics are naturally occurring products, often found in moulds. None of this changes the fact that evolution is at work, as Alekshun & Levy point out, and that bacterial evolution is of critical importance to modern medicine.
DaveScot | Quote | | Experiments were purported to have “proven” that antibiotic resistance evolves de novo. Talkorigins makes this claim in multiple places. Therein lies the dead icon. |
Antibiotic resistance can be achieved by horizontal acquisition of resistance genes, by recombination, or by even a single nucleotide substitution.
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You never step on the same tard twice—for it's not the same tard and you're not the same person.
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