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Author Topic:   Mimicry: Please help me understand how
Chiroptera
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Posts: 6833
From: Oklahoma
Joined: 09-28-2003
Member Rating: 7.0


Message 7 of 241 (411178)
07-19-2007 8:43 AM
Reply to: Message 1 by Lampropeltis
07-14-2007 3:04 PM


This answer was already suggested by Richard Dawkins in The Blind Watchmaker (and hinted at by another poster).

A bug that looks only ever so slightly more like a bird dropping or twig or leaf or may not fool you (or a bird or another, bigger bug) if you happen to look directly at it in broad daylight.

But out of the corner of your eye, it might just be enough to escape your attention. So, assuming that some bugs are first noticed by birds out of the corners of their eyes, slightly fewer bugs that are ever so slightly harder to detect will be eaten than "normal" bugs. Also, at twilight, when light levels are lower and it's harder to see anything, being ever so slightly harder to see may be just enough to avoid being eaten.


Q: If science doesn't know where this comes from, then couldn't it be God's doing?

A: The only difference between that kind of thinking and the stereotype of the savage who thinks the Great White Hunter is a God because he doesn't know how the hunter's cigarette lighter works is that the savage has an excuse for his ignorance. -- jhuger


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Replies to this message:
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Chiroptera
Member
Posts: 6833
From: Oklahoma
Joined: 09-28-2003
Member Rating: 7.0


Message 12 of 241 (411682)
07-21-2007 8:36 PM
Reply to: Message 10 by Modulous
07-21-2007 7:06 PM


off-topic
Ah, Ledyard Stebbins. I remember his book, Darwin to DNA, Molecules to Humanity. I got this book free when I subscribed to Scientific American in 1982 or 1983, shortly after I dumped creationism. I still had a lot of questions about evolution at that time, and this book was instrumental for a key insight that I didn't really understand before.


Q: If science doesn't know where this comes from, then couldn't it be God's doing?

A: The only difference between that kind of thinking and the stereotype of the savage who thinks the Great White Hunter is a God because he doesn't know how the hunter's cigarette lighter works is that the savage has an excuse for his ignorance. -- jhuger


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 Message 10 by Modulous, posted 07-21-2007 7:06 PM Modulous has not yet responded

  
Chiroptera
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Posts: 6833
From: Oklahoma
Joined: 09-28-2003
Member Rating: 7.0


Message 110 of 241 (429186)
10-18-2007 6:48 PM
Reply to: Message 109 by garyl43
10-18-2007 6:37 PM


Hi, gary, and welcome to EvC.

Why the need for evolution if the plant, insect or animal was able to survive and reproduce just fine for millions of years before it was able to mimic anything else?

The issue isn't being able to survive and reproduce just fine. The issue is being more likely to survive and reproduce. Consider a population of a certain species of beetles. If those who look ever so slightly more like Dick Cheney happen to have a better chance of surviving and reproducing than the ones who don't look as much like Dick Cheney, then the next generation of beetles will have more individuals that look ever so slightly more than Dick Cheney.

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Why would a living organism actually make it's survival totally dependant on 1 other species to reproduce....

Not the topic of this thread.

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How does a plant know the shape, size, geometry and color of the female wasp and the chemical makeup of it's pheromones since it can't feel the shape, see or smell the female wasp? Heck, how does it even know that wasps exist?

It doesn't. Just that the particular plants that happen to look or smell more like a wasp will produce more offspring than those who don't, so in the next generation there will be more plants that look or smell slightly more like a wasp.

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How does a species then morph itself into a copy of whatever it is it "thinks" it needs to be....

The species doesn't "morph itself". In one generation, some will look more like a wasp, others will look less. If the ones who look more like a wasp produce more offspring, then the next generation will have more individuals that look more like wasps. After a few generations, the ones that look more like wasps will outnumber those that don't. As new variations in features arise, some will look even more like wasps -- if those produce more offspring, then the next few generations will see this population look even more like wasps. And so forth.

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How does the insect know that birds will not eat bird droppings?

They don't. It just happens that those individuals that look more like bird droppings will be eaten less than those who don't -- and so will produce more offspring that, presumably, will inherit those features that made the parents look somewhat like bird droppings.


In many respects, the Bible was the world's first Wikipedia article. -- Doug Brown (quoted by Carlin Romano in The Chronicle Review)

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Chiroptera
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Posts: 6833
From: Oklahoma
Joined: 09-28-2003
Member Rating: 7.0


Message 117 of 241 (429201)
10-18-2007 7:59 PM
Reply to: Message 116 by garyl43
10-18-2007 7:55 PM


Oops.
Huh. That's not what you said:

In order for it to reproduce it had to have all this right the first time or it would have simply died out.


In many respects, the Bible was the world's first Wikipedia article. -- Doug Brown (quoted by Carlin Romano in The Chronicle Review)

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Chiroptera
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Posts: 6833
From: Oklahoma
Joined: 09-28-2003
Member Rating: 7.0


Message 121 of 241 (429217)
10-18-2007 9:02 PM
Reply to: Message 109 by garyl43
10-18-2007 6:37 PM


My mistake.
Why would a living organism actually make it's survival totally dependant on 1 other species to reproduce, like this orchid: https://www.youtube.com/watch?v=-h8I3cqpgnA ? Seems to me it would diversify as much as possible to increase it's chances of survival according to evolution.

I can't watch YouTube at work, so I had to wait until I got home to watch it. I guess it is on topic for this thread after all; I thought this was going to be a different orchid example.

The answer to this question is that orchids don't look ahead and see what would be the best, long term adaptation to take. What matters is what it takes to produce the most progeny for the very next generation.

In the case of these orchids, what happened is that those that looked and smelled just a little bit more like a wasp would attract a few more wasps as pollinators; since the initial changes were small, it probably wouldn't have lost out on the other pollinators that were around.

In time, by looking and smelling more like a wasp -- and presumably looking and smelling less like a flower full of tasty nectar -- it would have lost out on the other pollinators -- in fact, maybe it would even have scared other pollinators away. But by this time, by looking and smelling so much like a wasp, it was guaranteed that wasps would actually visit, without fail. And so it would end up more likely to be pollinated, and so would be more likely to produce progeny than those orchids looking and smelling less like wasps.

-

The other questions were already answered in this post. I'm flattered that my answers were so clear and to the point of your questions that you felt no need to question any of it.


In many respects, the Bible was the world's first Wikipedia article. -- Doug Brown (quoted by Carlin Romano in The Chronicle Review)

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Chiroptera
Member
Posts: 6833
From: Oklahoma
Joined: 09-28-2003
Member Rating: 7.0


Message 124 of 241 (429402)
10-19-2007 3:42 PM
Reply to: Message 123 by garyl43
10-19-2007 3:11 PM


What I'm saying is that to me natural selection does not explain what I'm seeing here.

Huh. And to me, natural selection does explain what I'm seeing here.

I guess this is why "what seems to me" is a pretty poor method to use in the sciences.

-

Also, natural selection would dictate that the species with the broadest methods of reproducing would be the one to proliferate, not the one that narrows it's possibilities to one rare species of wasp in a specific local

"Natural selection" doesn't dictate anything. What happens is that some individuals in a population will produce more offspring than others in the same population; often this difference is due to physical, inherited characteristics; and so in the next generation there will be more individuals that will have this favorable characteristic. We call this "natural selection". Natural selection is not an agent -- it is a label for a certain phenomenon that occurs.

A slight change may make a flower less attractive to a broad range of insect species, but also may make it more attractive to one particular species of insect. If, overall, this causes the flower to be visited more often, be more likely to pollinate, and so allow the plant to be more likely to reproduce than other plants, then the next generation will have more individuals with that sort of flower.

Edited by Chiroptera, : changed "phrase that describes" to "label for"


In many respects, the Bible was the world's first Wikipedia article. -- Doug Brown (quoted by Carlin Romano in The Chronicle Review)

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