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Member (Idle past 5790 days) Posts: 185 From: alexandria va usa Joined: |
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Author | Topic: 17-year locusts and evolution | |||||||||||||||||||||||
redwolf Member (Idle past 5790 days) Posts: 185 From: alexandria va usa Joined: |
An obvious evolution question has just now shown its face again for the first time since 1987. Okay all you evolutionites out there:
How exactly did the 17-year locust "evolve"?
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AdminSylas Inactive Member |
Thread moved here from the Proposed New Topics forum.
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jar Member (Idle past 393 days) Posts: 34026 From: Texas!! Joined: |
By hiding well.
I had an idea this would come up with the new building going on at the Creation Center. But what is hard to understand about the 13 or 17 year locusts (or the third species recently discovered) other than "Why were they called locusts?" Aslan is not a Tame Lion
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crashfrog Member (Idle past 1466 days) Posts: 19762 From: Silver Spring, MD Joined: |
How exactly did the 17-year locust "evolve"? Natural selection and random mutation. I think the more interesting question is why did it evolve? As I understand it, the periodicity is a response to predation.
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jar Member (Idle past 393 days) Posts: 34026 From: Texas!! Joined: |
the lemmings march to the sea and many, many plants that lie dormant for extended periods or bloom once and then die. One problem is with something that has this long of a periodicity it is hard to get funding for adequate research. With a 17 year cycle, a researcher might spend his whole career and only be able to observe two instances.
Aslan is not a Tame Lion
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RAZD Member (Idle past 1404 days) Posts: 20714 From: the other end of the sidewalk Joined: |
There are many species of locust that have differing years before reaching maturity, most of them 'normal' in a 2 to 8 year range with some flux back and forth.
Either from these more 'normal' species or similar ancestors, the periodical cicadas have evolved: 7 distinct species -- 4 that emerge in 13 year cycles (one recently discovered) and 3 that emerge in 17 year cycles -- and it appears that each of the 17 year species is related to one of the 13 year species, thus parallel evolution repeating a pattern of increasing cycle time. The fact that both of these long periods are prime numbers has been one of their most facinating aspects. Of course this makes it very difficult for a predator to match the periodicity, thus allowing the large swarms to emerge and overwhelm the predator base, ensuring sufficient mating occurs in the few days the adults live for the species to survive. Last thing I remember reading was that the scientists believe that the flow of sap in the roots tells the nymphs when to emerge. see University of Michigan Museum of Zoology, Insect Division, Cicada Webpage (click) for a good article on each of the species involved. My brothers and I collected bugs as kids growing up in Ann Arbor a number of 17 year cycles ago, and the 17 year cicada was in the collection. we are limited in our ability to understand by our ability to understand RebelAAmerican.Zen[Deist
{{{Buddha walks off laughing with joy}}}
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Unseul Inactive Member |
Theres been an article released in nature about this occurence actually.
Nature - Not Found Dunno how the web links work in this forum, but thats it. The article suggests that the predator theory may be flawed, as there are many predators out there that will happily eat cicadas, and although it means there wont be one specific predator, they're still getting eaten a lot. Another theory the article mentions is that it could be to prevent interbreeding between the species, reducing the chance of a hybrid occuring, and if it does occur using such large prime numbers reduces the chance of the hybrid breeding again. But im not sure how selection would work on this either. Unseul Give a man a fire and he's warm for a day. Set a man on fire and he's warm for the rest of his life....
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KCdgw Inactive Member |
I would say the staggered periods have more to do with avoiding interspecific competition than with predation.
KC
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Mespo Member (Idle past 2884 days) Posts: 158 From: Mesopotamia, Ohio, USA Joined: |
If a 13 year locust falls in love with a 4 year locust, would that make a 17 year locust? (13+4)
Or if a 17 year locust gets kicked out of the club and is demoted, would that make it a 13 year locust (17-4) or some other normal locust (17-x)? As stupid as it may sound, is there a possiblity that the genes regulating emergence be additive or subtractive in their timing sequence IF (big if) locust species can cross-breed? (:raig
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zephyr Member (Idle past 4550 days) Posts: 821 From: FOB Taji, Iraq Joined: |
quote:It sounds like they've got the cart before the horse on that one. Species don't evolve new traits for the purpose of creating/maintaining reproductive isolation; rather, isolation allows the accumulation of traits that produce separate species. Unless you think evolution is guided at every step, it doesn't hold water. I always found the predator idea very intriguing, but I don't know enough cicada specifics to really judge its merits.
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Mespo Member (Idle past 2884 days) Posts: 158 From: Mesopotamia, Ohio, USA Joined: |
RAZD writes: Last thing I remember reading was that the scientists believe that the flow of sap in the roots tells the nymphs when to emerge. That doesn't make sense. A locust nymph embedded by a tree root will emerge "on time" with his buddies regardless of drought, flood or Scott's Turf Builder on the ground above? The reason I mention it is that my neighbor's 180 acre farm includes 2000 taps in sugar maples to collect spring sap for processing into maple syrup. The flow of sap through the trees (and roots) is absolutely affected by weather patterns and temperature cycles. It does not seem to be related to calendar emergence cycles for a particular locust brood. And yet, out the little buggers come, right on, uh, "time". (:raig
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redwolf Member (Idle past 5790 days) Posts: 185 From: alexandria va usa Joined: |
It's really hard to picture something like that evolving.
My own GUESS would be that the 17 year locust was originally designed as a signal of some sort, i.e. as a sign for some recurring event or celebration at 17-year intervals. I mean, if some biting fly or mosquito came out every 17 years you might figure it to be a microevolutionary adaptation but the locust is decorative like butterflies.
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zephyr Member (Idle past 4550 days) Posts: 821 From: FOB Taji, Iraq Joined: |
quote:I always to my best to recognize when I'm mistaking my own lack of imagination for a real-life impossibility. Try it! quote:Why is that... because ancient people couldn't count that high? quote:Decorative? Some people hate them. They scared the crap out of me as a kid. I love 'em now, especially deep-fried with ketchup Regardless, the sensory response of a common species of primates to a particular insect is an incredibly poor basis for speculation as to the insect's origins.
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jar Member (Idle past 393 days) Posts: 34026 From: Texas!! Joined: |
You can never claim that redwolf lacks imagination.
Aslan is not a Tame Lion
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RAZD Member (Idle past 1404 days) Posts: 20714 From: the other end of the sidewalk Joined: |
Your neighbor also knows that he cannot collect good sap during the winter or late into the summer, that the best flow is when you have freezing nights and thawing days. You could measure the sap flow on an annual basis and know when spring arrives.
The emergence of the nymphs seems to be temperature driven once the correct number of years have passed, so it is not on the same day of the year. That takes care of the weather patterns and temp cycles. we are limited in our ability to understand by our ability to understand RebelAAmerican.Zen[Deist
{{{Buddha walks off laughing with joy}}}
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