tag:blogger.com,1999:blog-7447544468792389936.post2836583280832331262..comments2024-02-26T21:18:23.165-08:00Comments on CHIMERAS: The curse of drug-resistant TB strainsAnonymoushttp://www.blogger.com/profile/09922888671399516573noreply@blogger.comBlogger5125tag:blogger.com,1999:blog-7447544468792389936.post-24939327861064552262012-01-09T07:08:23.239-08:002012-01-09T07:08:23.239-08:00An addendum from my dad: the ability to evolve suc...An addendum from my dad: the ability to evolve such mutations probably pertains to numerous organisms, so long as they are aploid. That's because mutations in diploid organisms – whether advantageous or not – may or may not be expressed phenotypically. If they aren't expressed phenotypically they may or may not persist.Anonymoushttps://www.blogger.com/profile/09922888671399516573noreply@blogger.comtag:blogger.com,1999:blog-7447544468792389936.post-26987110470560832442012-01-09T06:49:38.909-08:002012-01-09T06:49:38.909-08:00Thanks for the answers, both of you. Very interest...Thanks for the answers, both of you. Very interesting.Steve Halterhttps://www.blogger.com/profile/03160423930602205230noreply@blogger.comtag:blogger.com,1999:blog-7447544468792389936.post-41889583754689996622012-01-06T14:30:06.134-08:002012-01-06T14:30:06.134-08:00Thanks, Lab Rat, that's really interesting. Th...Thanks, Lab Rat, that's really interesting. The same happens with viruses: the ones that mutate faster (HIV, influenza) will evolve more rapidly, but there's a threshold in how big a mutation rate can be: if you can tweak the mutation rate to be over a certain threshold, at that point the virus mutates so rapidly that most mutations start being deleterious and the virus will eventually go extinct.Anonymoushttps://www.blogger.com/profile/09922888671399516573noreply@blogger.comtag:blogger.com,1999:blog-7447544468792389936.post-26478200690236170122012-01-06T14:21:31.405-08:002012-01-06T14:21:31.405-08:00@Steve: All bacteria are capable of mutating, but ...@Steve: All bacteria are capable of mutating, but there are some bacteria that are more willing to share their DNA than others, allowing the resistance to spread faster. Staph aureus, paradoxically, is not wonderfully good at sharing DNA around, but it's found one spectacular party trick and it utilising it well.<br /><br />Interestingly enough the more stress you put bacteria under, the *more* they mutate in a sort of "evolve quick or die" response. Bacteria that are almost wiped out by antibiotics are therefore far more likely to evolve resistance than those that just exist happily in the normal population.Lab Rathttps://www.blogger.com/profile/07962574174521597312noreply@blogger.comtag:blogger.com,1999:blog-7447544468792389936.post-39211842663995291562012-01-06T07:16:35.723-08:002012-01-06T07:16:35.723-08:00Interesting as always! I wonder, do most viral/bac...Interesting as always! I wonder, do most viral/bacterial "diseases" share this ability to evolve resistant mutations or are there categories (HIV, TB, MRSA?) that are especially good at it?Steve Halterhttps://www.blogger.com/profile/03160423930602205230noreply@blogger.com