Pat, biologists have recently been studying entire gene families that are present in organisms as diverse as arthropods and vertebrates (Hox genes is a great example: http://en.wikipedia.org/wiki/Hox_gene). These "gene families" are groups of genes that number from less than a dozen to several dozen genes, and have important functions in determining specific body structures or the entire body plan, e.g., body shape, segmentation and vision. So, we have discovered specific genes that affect evolution beyond species/genus level and that can, theoretically, turn a butterfly body plan into something else. The only reason we won't be able to experimentally do this immediately (not that there is any reason to try this), is that evolution across the family/order/class levels involves hundreds of thousands of mutations. Sequencing and identifying functions of these mutations is, of course, technically overwhelming at this point. But molecular and evolutionary biologists are working on this and we already know enough to put two and two together in terms of specific mutations, gene function and overall body plan.
By the way, there is an interesting example of how much we know about how organisms work and why: http://www.sciencemag.org/content/329/5987/52.abstract All this is, however, deviating from the goals of ButterflyIndia at this point, so I will stop this discussion thread on the group from my side. Please write to me personally if you want to take this further. With best wishes, Krushnamegh. ------------------------------------------------- Krushnamegh Kunte, PhD Post-doctoral Research Fellow FAS Center for Systems Biology Harvard University 52 Oxford St Northwest Lab Room 458.40-3 Cambridge, MA 02138, USA. Ph: (617) 496-0078 Cell: (512) 577-1370 Fax: (617) 495-2196 Email: [email protected] Other emails: [email protected], [email protected] Personal website: http://www.people.fas.harvard.edu/~kunte/index.htm Indian Foundation for Butterflies: http://ifoundbutterflies.org/ Google profile: http://www.google.com/profiles/krushnamegh ------------------------------------------------- > From: Pat <[email protected]> > Reply-To: butterflyindia <[email protected]> > Date: Fri, 7 Jan 2011 01:21:28 -0500 > To: butterflyindia <[email protected]> > Subject: Re: [ButterflyIndia] Re : Lets do something for Butterfly India - > Critique Part 1 > > Hello, Krushnamegh, > > You have obviously done a lot of study of this. I respect your knowledge. > > I just have one question. In all of the examples you have seen, have you > ever seen any example of where such mutations resulted in an organism > which is clearly another or new genus (which could be a malleable > classification), or even a member of another or new family (which, > hopefully, wouldn't be)? > > A couple of examples, if I may. When the Heliconius butterflies had a > new wing pattern, was it anything more than different coloration, or did > it become a distinctly different butterfly, or something other than a > butterfly altogether? Same question with respect to Papilio. I have seen > a lot of different wing patterns (coloration) in Heliconius of various > species, but I have yet to see a Heliconius that didn't have the > characteristic elongated wings. But even if the wing shape changed, it > would still be a butterfly. > > I will point out that I don't know of anybody who has any knowledge of > the issues or facts who denies that MICRO-evolution (change within > species or genus) occurs. I think that's all we're talking about here. > > Pat Goltz > > Kunte, Krushnamegh wrote: >> >> >> Pat and others who care about this, >> >> Biologists have now identified many specific mutations that have >> enabled species to persist in changing environments in a specific way. >> Molecular and physiological bases of many of these mutations are now >> well known. It is also well known in many organisms how natural >> selection favored these mutations. So your impression that "Natural >> selection only causes some species to die off" is not true. Most of >> the well-documented examples are not related to butterflies so I will >> not dwell on this here very much but you should look up work by >> Harvard's Hopi Hoekstra on beach mice, and Stanford's David Kingsley's >> work on stickleback fish. There are also many examples in fruitflies. >> >> Molecular genetic bases of morphological changes in butterflies have >> not been studied as well but several labs have started looking at >> this. The most advanced work is on the African /Bicyclus anynana/, >> which is related to our Bushbrowns (/Mycalesis/ spp.), on which >> ButterflyIndia¹s Ullasa Kodandaramaiah has published a little bit. A >> major research program is under way by James Mallet (University >> College London), Chris Jiggins (Cambridge University) and Marcus >> Kronforst (Harvard University) to hunt down genes, and specific >> mutations, responsible for changes in wing patterns of neotropical/ >> Heliconius/ butterflies. Marcus Kronforst and I have also started >> looking for genes involved in mimicry in Indian swallowtail >> (/Papilio/) butterflies. We will have updates on this soon. In a >> forthcoming paper we will also show a superb signature of natural >> selection favoring genetic recombination in a /Papilio /butterfly. So >> I think you will change your mind if you understand what scientists >> have been finding out lately. And there is more to come. >> >> You are correct that genetic drift is often bad. But not always. >> Again, look up work by James Mallet on/ Heliconius/ butterflies, which >> has shown that drift may actually help establish novel wing patterns, >> which are under selection once they become established in a >> population. Drift is an excellent null hypothesis for most work on >> molecular evolution, but scientists more often than not end up finding >> signature of natural selection rather than drift in a lot of genetic >> variation that has been characterized. This applies to organisms from >> bacteria to fruitflies, which have been very well studied, and it will >> most likely be true for other organisms that are being studied. >> >> I think W. H. Evans, whose identification keys all serious butterfly >> watchers still use in India, said it best: ³It has been asserted that >> the story of evolution is written on the wings of butterflies, if only >> we could attain the skill to interpret the writings. A full knowledge >> of nature can only be obtained by careful observation under natural >> conditions correlated with the study in museums, laboratories and >> libraries of the various forms under which nature displays itself and >> of the information gained by other observers.² >> >> I hope that Indian butterflies will continue to play a role in >> advancing this vision. There is an opportunity and a challenge for >> those who want to go beyond mere identifications of their photographs. >> >> With best wishes, >> >> Krushnamegh. >> ------------------------------------------------- >> >> Krushnamegh Kunte, PhD >> >> Post-doctoral Research Fellow >> FAS Center for Systems Biology >> Harvard University >> 52 Oxford St >> Northwest Lab Room 458.40-3 >> Cambridge, MA 02138, USA. >> >> Ph: (617) 496-0078 >> Cell: (512) 577-1370 >> Fax: (617) 495-2196 >> Email: [email protected] >> Other emails: [email protected], [email protected] >> >> Personal website: http://www.people.fas.harvard.edu/~kunte/index.htm >> <http://www.people.fas.harvard.edu/%7Ekunte/index.htm> >> Indian Foundation for Butterflies: http://ifoundbutterflies.org/ >> Google profile: http://www.google.com/profiles/krushnamegh > > > ------------------------------------ > > --- > Follow http://twitter.com/DiversityIndia > ---Yahoo! Groups Links > > > -- Enjoy
