[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Re: Selective Extinction
Dann Pigdon wrote:
> Given the rapid reproduction rate of micro-organisms I suspect that
> they have the ability to evolve faster than macro-organisms.
> I wonder why people don't study evolution in microbes rather than
> creatures like anole lizards? It probably wouldn't take 30 years to
> show results.
They do indeed, as someone has already mentioned. The problem is that
bacteria don't reproduce sexually, at least in the same sense as e.g.
mammals. However, they can evolve very fast, as you suggest. One of the
fun things they do is to spread virulence factors (antibiotic resistance
factors, immunosuppressors, etc.) by means of plasmids, small circular
lengths of DNA that might once have been bacterial viruses ("phages").
These *do* spread to other types of bacteria. In any case, the bottom
line is that the genetics of bacteria are a lot different from
vertebrates, making them less appropriate models for evolutionary
studies. Slime molds, _Dictostelium_ and the like, are eukaryotes, have
better genetics and (I think) an optional sexual mode of reproduction and
are coming into favor as a model. But I was never a slime mold man and
don't know much about them.