tag:blogger.com,1999:blog-8488546042136769604.post3268162573489303645..comments2023-11-08T22:27:08.966-06:00Comments on Sex, Genes & Evolution: Bdelloid Rotifers-Ancient Asexuals?John Logsdonhttp://www.blogger.com/profile/17531681775278694585noreply@blogger.comBlogger8125tag:blogger.com,1999:blog-8488546042136769604.post-81888475848832265242007-07-08T00:28:00.000-05:002007-07-08T00:28:00.000-05:00If rotifers did have sex, would they tag you .. I ...If rotifers did have sex, would they tag you .. I don't know but I hereby <A HREF="http://phylogenomics.blogspot.com/2007/07/i-have-been-f-tagged.html" REL="nofollow"> tag you. </A>Jonathan Eisenhttps://www.blogger.com/profile/07953790938128734305noreply@blogger.comtag:blogger.com,1999:blog-8488546042136769604.post-77760201567903038432007-03-27T22:10:00.000-05:002007-03-27T22:10:00.000-05:00I'm sorry for the delayed reply here, but sometime...I'm sorry for the delayed reply here, but sometimes procrastination pays. It turns out that John Wilkins has posted recently on the topic of <A HREF="http://scienceblogs.com/evolvingthoughts/2007/03/microbial_species_postlude.php#more" REL="nofollow">microbial species concepts</A> on his blog <A HREF="http://scienceblogs.com/evolvingthoughts/" REL="nofollow">Evolving Thoughts.</A>John Logsdonhttps://www.blogger.com/profile/17531681775278694585noreply@blogger.comtag:blogger.com,1999:blog-8488546042136769604.post-58380040705336118062007-03-23T07:51:00.000-05:002007-03-23T07:51:00.000-05:00Mr. Logsdon, could you please explain why it was/i...Mr. Logsdon, could you please explain why it was/is believed that new species cannot evolve from asexual organisms? Is it because asexual reproduction does not allow for enough genetic variation? And if so, does that mean that asexual organisms diversifying into new species indicates that it is not natural selection?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-8488546042136769604.post-69805387293465714452007-03-22T07:26:00.000-05:002007-03-22T07:26:00.000-05:00I also suspect that bdelloids may have very crypti...I also suspect that bdelloids may have very cryptic males. The darwinuloid ostracods were another maleless group, but not too long ago lost that distinction. I had a relevant discussion of this topic in a recent <A HREF="http://snailstales.blogspot.com/2007/02/occasional-male-ostracod.html" REL="nofollow">post</A>.AYDIN ÖRSTANhttps://www.blogger.com/profile/09891160904748206385noreply@blogger.comtag:blogger.com,1999:blog-8488546042136769604.post-80814046148873014402007-03-21T21:10:00.000-05:002007-03-21T21:10:00.000-05:00rpm, you got my drift. maybe the ? in the post tit...rpm, you got my drift. maybe the ? in the post title tipped you off...<BR/><BR/>Yes, I am skeptical of the asexual status of bdelloid rotifers. It's not for lack of looking: people have been doing so for more than a century and still there is no evidence for sex or males. More recently, molecular data have been brought to bear on the question. This is mostly the work or David & Jessica Mark Welch and Matthew Meselson. These data are all consistent with asexuality. <BR/><BR/>But as I am very fond of saying: "Absence of evidence is not evidence of absence". Some other putative ancient asexuals have been recently de-bunked (e.g., darwinulid ostracods). So, even though the bdelloid life histories are reasonably well-understood, we may still have something to learn. <BR/><BR/>As for the paper at hand, I'm not criticizing it per se. I think that the data and analyses are quite well-done. The problem I have centers on what the initial assumption is and how that affects the conclusion. If bdelloids are indeed asexual, then this is a surprising and novel answer. If they are sexual, then the answer they obtained is the expected one.John Logsdonhttps://www.blogger.com/profile/17531681775278694585noreply@blogger.comtag:blogger.com,1999:blog-8488546042136769604.post-28867379355534597002007-03-21T13:14:00.000-05:002007-03-21T13:14:00.000-05:00Are you arguing for cryptic sexual reproduction in...Are you arguing for cryptic sexual reproduction in bdelloid rotifers? Are people jumping to conclusions without a good understanding of life history?RPMhttps://www.blogger.com/profile/00344508931818143159noreply@blogger.comtag:blogger.com,1999:blog-8488546042136769604.post-7504488258544131702007-03-20T22:50:00.000-05:002007-03-20T22:50:00.000-05:00The main issue is how to distinguish such "species...The main issue is how to distinguish such "species" one from the other if they are not reproducing sexually. The root of this "problem" is in applying the biological species concept. This is a serious issue in defining "species" in prokaryotes (well, at least some people think it's serious). In sum, it gets down to "what is a species?". In this case, these asexual organisms appear to be separate species in the same way that sexuals differ from one another (both morphologically and molecularly).John Logsdonhttps://www.blogger.com/profile/17531681775278694585noreply@blogger.comtag:blogger.com,1999:blog-8488546042136769604.post-59715447961613636792007-03-20T22:41:00.000-05:002007-03-20T22:41:00.000-05:00I'm confused by: "The evolution of distinct specie...I'm confused by:<BR/><I> "The evolution of distinct species has often been considered a property solely of sexually reproducing organisms. In fact, however, there is little evidence as to whether asexual groups do or do not diversify into species."</I><BR/><BR/>doesn't this imply that there would only be one asexual species?Jim Lemirehttps://www.blogger.com/profile/14000051293978203511noreply@blogger.com