August 1, 2005 at 4:31 pm #1573
How could a butterfly be the result of random mutation… The developemental stages are so specific it is hard to imagine an inbetween form. Could someone shed some light?
August 1, 2005 at 4:48 pm #27857
What do you mean by “random mutation”?
August 1, 2005 at 5:20 pm #27859
you know… genetic faults due to mutation, and then with survival of the fittest you get the genes that work.. but how can such a complex thing as a 3 stage butterfly developement thingy work????
August 1, 2005 at 5:38 pm #27861
If you’re talking complexity, there are many creatures that have a larvae form, sponges, sea squirts, frogs….
August 1, 2005 at 10:59 pm #27869
yes, I know that, but what I don’t understand is how it can be helpful in surviving to have a multiple stage developement.
August 2, 2005 at 12:13 am #27871JamesParticipant
Think of metamorphosis as growing up from young to adult, just in one spurt.
August 2, 2005 at 2:26 am #27877
Because they are equipped with several genes that are responsible to each differentiation stage (metamorphosis phases), that’s help them to keep survive in each of their instars (development phases).
Also, there are a couple of hormones that regulate their stages of life, you know JH and ecdyson. Oh this reminds me of a research done by my friend from another lab:
– She kept Attacus atlas (wild silkmoth cater… oops larvae… it is the same though hehe… OMG, I am shivering and can feel my cold sweat while writing this…awawawawaa…) in her lab. I called this moth as ‘kite’ because if you spread wings of this moth, it will as long as your 15 inch monitor whoaaaaa…
– She administered JH for the first group and applied ecdyson for the second group. The third group was for control.
– After few times, larvae from the first group became giant larvae compared to the third group (whoaaa I saw monster brrrrr…), the instar phase was longer. While larvae from the second group started to make a cocoon, actually that was too early or their instar phase was shorter, because the third group (control) still in their middle instar phase.
August 2, 2005 at 4:01 am #27885
How it would be desirable to have multiple stages?
Think food sources. If adults and adolescents ate the same food, there would be a potential food shortage, so this is a form of resource partitioning.
August 2, 2005 at 5:23 am #27902
Because JH keeps insects in larva stage (juvenile), so they will have extra instar phase(s).
August 4, 2005 at 3:08 pm #28024
thank you.. i think i get it 🙂 😉
August 5, 2005 at 2:20 am #28031Darwin DudeParticipant
[i]How it would be desirable to have multiple stages?
Think food sources. If adults and adolescents ate the same food, there would be a potential food shortage, so this is a form of resource partitioning.[/i]
Actually I don’t think that is a good argument as it would imply some sort of group selection. I suspect that it is more likely that some advantage accrues to the individual caterpillar from having the food source they do as teenagers..rather than any implied competition with the adults.
October 5, 2005 at 4:18 am #30426SpeadskaterParticipant
and if they stayed in their larva stage they would only eat leaves their whole life, which might cause a shortage of food and may kill the tree that provides the leaves. but having two stages allow them to use both nectar and leaves so that no resource is used too much or too little.
If you can use the nectar to your advantage why would you waste it and just eat just leaves?
Again…I’m young so if I’m wrong tell me. this is just my thinking with little experiance.
January 7, 2007 at 7:06 am #64912
Sorry to bring up such an old post, but I have some serious questions on how a butterfly can evolve.
I could buy the fact that the caterpillar stage evolved from a lower species except for the fact that caterpillars are incapable of reproduction. Even if they once were capable of reproduction and lost that ability after they evolved the rest of the way to a butterfly, one would think that the evolution process would end when the creature dissolves into liquid mush inside its chrysalis (or cocoon for other such creatures). Then it would have to undergo millions of years worth of evolution in just a few days or weeks before it rots. It has to evolve from a worm like creature with no real legs, simple eyes, and chews its food to a completely different creature with six long segmented legs, very complex eyes, wings with the ability to fly and navigate and a tube to suck nectar instead of chewing food.
All of that DNA would have had to be in place before it built its cocoon and since it never had a reason before, how did it evolve ?
The only other explanation I can think of is if the butterfly evolved first, but wouldn’t giving birth to a worm be backwards evolution ? Even so, it would still need to overcome the problem of the DNA needed to complete metamorphosis. What would be the evolutionary process to develop it ?
Is it possible that the metamorphosis started at the single cell stage and both halves were able to evolve independently and still stay in perfect harmony with each other for billions of years, relying on each other for survival and reproduction ?
January 7, 2007 at 5:38 pm #64973
Metamorphosis…. or …. ecdysis… is an amazing phenomenon of Arthropod world…. today also we are searching for the reasons… for evolution of ecdysis in arthropods…
But I think it evoled to adapt the environment in which caterpilar stage was seem to be inconspecuous and difficult to get mate…. winged stage is easy to find mate and migrate too…
January 7, 2007 at 9:15 pm #64981
Horizontal gene transfer?
January 8, 2007 at 3:04 am #65014quote mith:
Could you give a breif explanation of "horizontal gene transfer" or direct me to were I might be able to learn more about that ?
January 8, 2007 at 3:57 am #65021canalonParticipant
Horizontal gene transfer is the transfer of genes that do not happen during reproduction. see the vertical transfer as the one between generations, and the horizontal as a transfer that do not need reproduction. It is the case for acterial mating, but the gene transfer by viruses to build GMO also belong to this category.
January 8, 2007 at 4:11 am #65024
I have done a little research on google about horizontal gene transfer and some of the stuff I read seemed to refer to transferring genes from past generations. As pertaining to this topic, would it be fair to assume that the caterpillar evolved directly into the butterfly first, then developed the metamorphosis stage later using old info from the original evolutionary process ?
January 8, 2007 at 5:49 am #65046quote burninbriar:
It is seen that many Dipteran flies deposit there egg in caterpillars; so may be this is cause of gene tranfer some time and got new generation to evolve… 😛
January 10, 2007 at 5:13 am #65448
I’ve been going over this a lot and I can see where the horizontal gene transfer could account for a butterfly possibly having an egg hatch a baby caterpillar instead of a butterfly but that would still not account for the DNA required to make the caterpillar dissolve and reconstitute its self back into a butterfly. The only logical conclusion I can come up with is that the DNA for metamorphosis was formed when the first cell was formed. Does any one know if that DNA code for metamorphosis has been identified and if so, has it or anything resembling it been seen in other simple life forms ?
January 10, 2007 at 5:32 am #65463
Phylum Annelida, Arthropoda Shows Metamorphosis…. both complete and Incomplete…
Search Google for Genes for that…….
January 12, 2007 at 7:46 pm #66063DarbyParticipant
Let me give you a possible scenario –
Start with a winged insect, using some brief seasonal food source. To get from season to season, it uses eggs. The eggs hatch and the nymphs resemble the adults, quickly going through the stages to get there. As is generally true, the nymphs are not winged, and feed on the seasonal food source.
Occasional mutations may hatch the eggs early, or produce nymphs that are still somewhat embryonic, more like segmented egglets, but with some developed body parts, such as mouthparts and legs (this is not far off describing the larval stages of indirect developers). This alone would not probably be advantageous, unless combined with an ability to eat food other than the adult fare – those variants could hatch early, feed and grow, and be adults when the "real" food source becomes available (giving a pretty decent advantage to those adults, and somewhat isolating them reproductively). They would need to be able, in the next-to-last molt, to be able to become functional, winged, reproductive adults.
If this type of life cycle is successful enough, evolutionary pressures now exist on all stages, but since they fill different niches, their specialties will make them more and more specialized. You look today at the caterpillar-pupa-butterfly sequence, and it seems impossibly complex, but you just need a hint of it at the beginning you get you there. It’s all hypothetical, of course, but plausible, and there are probably several other plausible scenarios as well.
January 13, 2007 at 4:38 am #66160quote sachin_at_biog:
Thanks for the direction, I still haven’t had a chance to research it as much as I want, but I will. I was actually thinking more in the line of a single cell organism though.
Thats an interesting scenario, I need to think about this one some more. Although I see where you explain the stages, I still can’t get over the part where the caterpillar dissolves and then reconstitutes its self. I’m going to ponder you’re scenario some more.
January 13, 2007 at 6:31 am #66265quote Darby:
You are fabulous; Im going to search that more now……. 😛
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