Quoting Horse <[EMAIL PROTECTED]>: > Hi PLatt > > OK, forget viruses, as they are not strictly life. However, bacteria > (single and multi-cellular organisms) are true life and constitute the > majority of life on the planet. Bacteria are the bugs and super-bugs > that Ian referred to. > > Here's something from Wikipedia: > > "Bacteria, as asexual organisms, inherit identical copies of their > parent's genes (i.e., they are clonal). However, all bacteria can evolve > by selection on changes to their genetic material DNA caused by genetic > recombination or mutations. Mutations come from errors made during the > replication of DNA or from exposure to mutagens. Mutation rates vary > widely among different species of bacteria and even among different > clones of a single species of bacteria. Genetic changes in bacterial > genomes come from either random mutation during replication or > "stress-directed mutation", where genes involved in a particular > growth-limiting process have an increased mutation rate. > Some bacteria also transfer genetic material between cells. This can > occur in three main ways. Firstly, bacteria can take up exogenous DNA > from their environment, in a process called transformation. Often, the > genes transferred are not from within the main bacterial chromosome, but > are carried on a small circular piece of DNA called a plasmid. Genes can > also be transferred by the process of transduction, when the integration > of a bacteriophage introduces foreign DNA into the chromosome. The third > method of gene transfer is bacterial conjugation, where DNA is > transferred through direct cell contact. This gene acquisition from > other bacteria or the environment is called horizontal gene transfer and > may be common under natural conditions.[94] Gene transfer is > particularly important in antibiotic resistance as it allows the rapid > transfer of resistance genes between different pathogens." > > Bacteria are constantly evolving into new forms without human or other > interference and thus constitute ongoing biological evolution.
Well, that explains mutations that I just asked Ian about. But, I don't consider changes in types of bacteria evolutionary since they don't evolve into anything other than bacteria -- to the best of my knowledge. Do you know if anyone has observed bacteria evolving into something other than another species of bacteria? Thanks. ------------------------------------------------- This mail sent through IMP: http://horde.org/imp/ moq_discuss mailing list Listinfo, Unsubscribing etc. http://lists.moqtalk.org/listinfo.cgi/moq_discuss-moqtalk.org Archives: http://lists.moqtalk.org/pipermail/moq_discuss-moqtalk.org/ http://moq.org.uk/pipermail/moq_discuss_archive/
