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  1. 14 Feb '18 15:54
    The lifespan of Monarch Butterflies is very unique and complex. Can anyone explain why it evolved the way it did?

    http://monarchbutterflyusa.com/monarch-life-cycle/
  2. Subscriber sonhouse
    Fast and Curious
    24 Feb '18 09:01 / 1 edit
    Originally posted by @metal-brain
    The lifespan of Monarch Butterflies is very unique and complex. Can anyone explain why it evolved the way it did?

    http://monarchbutterflyusa.com/monarch-life-cycle/
    Not being a biologist I have no idea but that is not the only complex cycle going, look at Malaria:

    https://www.cddep.org/tool/life_cycle_malaria_parasite/

    And this site: Complex life cycles

    https://www.wired.com/2013/05/strange-life-cycles/
  3. 26 Feb '18 18:52
    Originally posted by @sonhouse
    Not being a biologist I have no idea but that is not the only complex cycle going, look at Malaria:

    https://www.cddep.org/tool/life_cycle_malaria_parasite/

    And this site: Complex life cycles

    https://www.wired.com/2013/05/strange-life-cycles/
    The Monarch butterfly has a longer lifespan for only the generation that migrates to Mexico. The other generations have short lifespans. Why are they not all long? That is what puzzles me. Is there an advantage to having a short lifespan? Why one generation and not the other?
  4. Standard member wolfgang59
    Infidel
    27 Feb '18 10:15
    Originally posted by @metal-brain
    The Monarch butterfly has a longer lifespan for only the generation that migrates to Mexico. The other generations have short lifespans. Why are they not all long? That is what puzzles me. Is there an advantage to having a short lifespan? Why one generation and not the other?
    A shorter life-span means faster adaptation.
  5. 27 Feb '18 13:19 / 7 edits
    Originally posted by @wolfgang59
    A shorter life-span means faster adaptation.
    that isn't really true. At least there is no direct casual link between the two. Species with shorter life-spans generally have but not always have (there are plenty of exceptions) relatively short reproductive cycles and, with all else being equal (which is very rarely exactly the case in reality), it is the relatively short reproductive cycles, not the shorter life-spans, that would result in faster genetic evolution in response to a change in the environment.

    An elephant's reproductive cycle is rarely less than a decade thus an elephant population isn't going to evolve much in just 10 years! But, in that very same time period, a whitefly (an insect pest) population can have MANY life cycles and thus can (as has often happened) rapidly evolve complete insecticide resistance. This would be still true even if each whitefly hypothetically had a maximum potential natural life-span of 100 years or even never died of aging but could only die of other causes! (obviously their average life-span will still be very short because of other causes of death not age-related)
  6. 01 Mar '18 19:02 / 1 edit
    Originally posted by @metal-brain
    The lifespan of Monarch Butterflies is very unique and complex. Can anyone explain why it evolved the way it did?

    http://monarchbutterflyusa.com/monarch-life-cycle/
    Clearly, as the article points out, the lifespan of different generations of butterflies is based on their reproductive cycle and periods of dormancy. No one knows why anything does anything, but it seems logical that Monarchs evolved that life cycle as a mechanism for surviving the winter.
  7. 02 Mar '18 16:33
    Originally posted by @wildgrass
    Clearly, as the article points out, the lifespan of different generations of butterflies is based on their reproductive cycle and periods of dormancy. No one knows why anything does anything, but it seems logical that Monarchs evolved that life cycle as a mechanism for surviving the winter.
    "No one knows why anything does anything, but it seems logical that Monarchs evolved that life cycle as a mechanism for surviving the winter."

    In Mexico? Kind of warm down there.
    Many insects survive the winter. Are you saying a house fly is no different?
  8. 02 Mar '18 16:48
    Originally posted by @metal-brain
    "No one knows why anything does anything, but it seems logical that Monarchs evolved that life cycle as a mechanism for surviving the winter."

    In Mexico? Kind of warm down there.
    Many insects survive the winter. Are you saying a house fly is no different?
    What does the house fly have to do with anything? The Monarchs lifespan can be explained through evolutionary mechanisms.
  9. 02 Mar '18 17:04
    Originally posted by @wildgrass
    What does the house fly have to do with anything? The Monarchs lifespan can be explained through evolutionary mechanisms.
    It does not explain why the other life cycles are so much shorter. Why shouldn't they have evolved with every life cycle longer? Do Monarch Butterflies go though diapause?

    https://www.abchomeandcommercial.com/blog/do-flies-hibernate/
  10. 12 Mar '18 18:52
    Originally posted by @wolfgang59
    A shorter life-span means faster adaptation.
    I suggested something similar in my first thread about this. I still think there might be something to it but it isn't easy to prove. Some species reproduce both sexually and asexually which appears to make your point irrelevant, but I think shorter lifespans may make a species' drive for average characteristics in the gene pool faster. Beauty is mostly average characteristics. There is a clear drive for us and other species to mate with individuals with average characteristics. Average now might be different than average 300 years ago though. A longer lifespan would mean more offspring from those that survive. Less generations might lead to a retarded formation of the average over time. Hard to prove though. For now just a theory, but I think I may be on to something.
  11. 05 Apr '18 01:36
    Originally posted by @wildgrass
    What does the house fly have to do with anything? The Monarchs lifespan can be explained through evolutionary mechanisms.
    What is your source of information?
    Flies typically live a couple of weeks, more or less, yet they survive the winter so their life span is prolonged to survive the winter. Flies do not hibernate according to articles I have read, but they go through "diapause". If duapause is why their life span is prolonged to survive the winter I am curious as to why that is. If you could find that out it may reveal a method to increasing man's lifespan.
    If Monarch Butterflies do not go through diapause it would be equally beneficial to study them for the benefit of longevity. Wouldn't you agree?