That's No Leaf — It's A Spider!

originally posted by: PhotonEffect

Accidental? What makes you say that? This type of masquerading happens with several other species of spider and other insects and animals. Makes it seem far from accidental.

Accidents aren't one off things you know? They can happen more than once and considering science estimates something like a trillion different species, I'd say it is quite likely for that to happen. Just playing the odds and all.

Wow, now that's a very nice story. But unfortunately it's not one rooted in science, just plain conjecture - at least as it pertains to this species. Unless of course someone can provide the study that's examined the dynamics of this creature in it's environment, mating habits, predation etc, as well as it's genetic make up. Would be helpful to know how many mutations it took for this Poltys to look and behave exactly like a leaf of it's environment. Which gene[s] is involved, phylogenetic history, selection signatures (if there any) and so forth. Otherwise what you said has no real basis in science I'm afraid. It sounds good though.

Well of course it is currently just conjecture. Because the spider was just discovered. However its a pretty safe bet since that is how every other species we've looked at over the years has evolved. You trying to dismiss his reasoning just because we haven't scientifically analyzed the spider's evolutionary history is ridiculous.

I knew it! I knew I shouldn't have clicked on this thread, but what'd I do, I clicked on the thread! Yikes!

originally posted by: PhotonEffect
Accidental? What makes you say that? This type of masquerading happens with several other species of spider and other insects and animals. Makes it seem far from accidental.

All genetic mutations are accidental, in the sense that they are genetic rolls of the dice based on biological propensity.

However, "looking like a leaf" is not an accident. That is a process involving many individual mutations, guided by the very "non-random" pressures of the creature's local environment.

originally posted by: Greggers
Wow, now that's a very nice story. But unfortunately it's not one rooted in science,

If you have a better description of natural selection, please provide it. Otherwise, what I decribed does indeed pertain to speciation via natural selection as it is described in science books all over the world -- erego, it is indeed based in science.

Oh heavens.... How does that thing even move? Doesnt look like it has a segmented body, just a dollop of nightmares

originally posted by: NerdGoddess
You know what really gets me about these types of glorious creatures? How the hell does a spider DNA know what a Leaf cell structure looks like, and is like ahh yeah we'll go with that. That will work wonders for this guy. ?!?!?! Nature, how you so smart yo?

-Alee

So true!! What and interesting world! My opinion Creation

a reply to: Krazysh0t

originally posted by: Krazysh0t
Accidents aren't one off things you know? They can happen more than once and considering science estimates something like a trillion different species, I'd say it is quite likely for that to happen. Just playing the odds and all.

Hi Krazysh0t,

How does the proliferation of species (nice link btw, I've referenced that one myself a few times) correlate to mutations being classified as accidental? I'm not sure how speciation addresses the question. Perhaps you could expound on this some more.

originally posted by: Krazysh0t
Well of course it is currently just conjecture. Because the spider was just discovered. However its a pretty safe bet since that is how every other species we've looked at over the years has evolved. You trying to dismiss his reasoning just because we haven't scientifically analyzed the spider's evolutionary history is ridiculous.

I don't see why you would call it ridiculous. We know nothing about the spider and already someone proclaims it's the result of natural selection from many many small accidental mutations. Based on what evidence exactly? When is conjecture ever good science?

And sorry, but it's not accurate to say "every other species we've looked at" has evolved by natural selection. That's a false claim and has no basis in the scientific literature. The science I know doesn't work on "safe bets" either. It works on hard evidence. Evidence, mind you, that can be refuted on any given day by better evidence, or a better interpretation of that evidence.

Evolutionary science relies on phylogenetic correlations and the history of a species genome to help paint a picture of how the species evolved in the first place. Take human evolution for instance. Does the evolutionary history of our genome not matter to how we evolved? Is that really a ridiculous question to ask?

a reply to: Greggers

originally posted by: Greggers
All genetic mutations are accidental, in the sense that they are genetic rolls of the dice based on biological propensity.

I disagree with the usage of the word "all"

Have you ever heard of a mutational hotspot ?

originally posted by: Greggers
However, "looking like a leaf" is not an accident. That is a process involving many individual mutations, guided by the very "non-random" pressures of the creature's local environment.

Again, you're only assuming that this is the way it happened. Based on what evidence though? For all we know this phenotype could've been result of gene expression. Maybe it was just one mutation of large effect. Perhaps even a product of transposable elements. How many genes are we talking? We don't know. Small incremental changes over millions of years is not an adequate explanation, especially with zero evidence of it.

originally posted by: Greggers
If you have a better description of natural selection, please provide it. Otherwise, what I decribed does indeed pertain to speciation via natural selection as it is described in science books all over the world -- erego, it is indeed based in science.

I wasn't taking issue with your definition of natural selection. It seems to be spot on. The issue was with your blind application of it in this case.

Nice! Creepy tho.

Fantastic Beasts and Where to Find Them?

China!

PhotonEffect: First of all, you're being far too literal here. I wasn't attempting to forecast the genetic history of this particular animal. I was using this specimen as a jumping off point to explain how genetics doesn't require special, unexplainable powers to "know what a leaf looks like."

Perhaps I should have used more cautious language, but you know, most of the time on these forums it is simply not required.

originally posted by: PhotonEffect

I disagree with the usage of the word "all"

Have you ever heard of a mutational hotspot ?

Are you suggesting the mutational hotspots are not based on "genetic propensity?"

Again, you're only assuming that this is the way it happened. Based on what evidence though? For all we know this phenotype could've been result of gene expression. Maybe it was just one mutation of large effect. Perhaps even a product of transposable elements. How many genes are we talking? We don't know. Small incremental changes over millions of years is not an adequate explanation, especially with zero evidence of it.

I'm playing the odds. A perfect adaptation such as this where an animal is able to accurately replicate its environment is very unlikely to have occurred as the result of a single mutation. Sure, it's possible. That would be pretty damned incredible though.

I wasn't taking issue with your definition of natural selection. It seems to be spot on. The issue was with your blind application of it in this case.

Are you suggesting that this particular species developed via some manner other than speciation via natural selection?

originally posted by: PhotonEffect
I wasn't taking issue with your definition of natural selection. It seems to be spot on. The issue was with your blind application of it in this case.

It doesn't seem like a stretch to say this is how natural selection works and we have plenty of evidence that's how it works in other species so it seems likely the same thing happened here.

If you really want to get pedantic you can accurately say that nothing in science is ever proven with 100% certainty and dismiss all claims on that basis. But if you are a little less pedantic you can acknowledge that if you've seen natural selection in thousands of other species, it wouldn't be a shocker to suspect it was also at work in a species you just discovered.

It's an amazing adaptation. Almost as amazing as the Leafy Sea Dragon



Isn't this more of a topic for the "Fragile Earth" forum than the "Science and Technology" forum? It's a cool new species but really no science or technology.

a reply to: Arbitrageur

Mimicry fascinates me, and this leaf/spider is an excellent example of how incredible an adaptation it can be. I was surprised to learn that there are several different classifications of biological mimicry (defensive, aggressive, reproductive, & automimicry). If you would like to learn more, the Encyclopedia of Earth has an entry that I was able to comprehend even with my nearly exhausted supply of brain-cells.

a reply to: theantediluvian

Just when you think you've seen everything - nature keeps getting cooler

a reply to: theantediluvian

Oh sure

You just had to post a great big oversized close up shot of the thing-that-shall-not-be-named.

... right there

... at the very top of your opening post

... where we would get hit with it the minute the thread opened up.










A pox on your family jewels for all eternity.

a reply to: CranialSponge


Bahahahaha! I couldn't of said it better myself! LOL!!!!!

originally posted by: Greggers

originally posted by: NerdGoddess
You know what really gets me about these types of glorious creatures? How the hell does a spider DNA know what a Leaf cell structure looks like, and is like ahh yeah we'll go with that. That will work wonders for this guy. ?!?!?! Nature, how you so smart yo?

-Alee

It starts with an accidental mutation that allows the animal to blend in with its environment. This accidental genetic camouflage would be unlikely to so closely resemble a leaf after the initial mutation, yet gave the creature an advantage over spiders without the mutation. Over millions of years, that particular spider is more successful and passes its genetics on more often, and every time there is another mutation that brings it closer to blending in with its environment, that mutation is selected for by the natural threats and opportunities in the environment itself, until eventually we end up with this thing.

So that first accidental mutation, as well as countless generations of mutations after, didnt really look much like a leaf, right? It took a looong time before it got to this pretty convincing looking leaf, right?

So, that first accidental mutation, and all those that followed which didn't look much like a leaf... If it didnt look like a leaf then, how did it help it to survive better than its non mutated brothers and sisters? It seems like it would be more of a hinderance than a "force multiplier" or whatever... It wouldn't be useful for survival until the point where it actually looked like a convincing leaf. But according to you it survived across eons of time with this useless, protruding mutation sticking out of its body that served no purpose until the day that it, accidentally, started to look like a leaf.

Maybe you're right. I have no way of knowing. But it sounds a little fishy to me, personally.

originally posted by: Night Star
I knew it! I knew I shouldn't have clicked on this thread, but what'd I do, I clicked on the thread! Yikes!

Lol. I was going to leave "spider" out of the title and then have the spider pic at the top of the OP but then I thought about the arachnaphobes and decided it was best to give everyone fair warning!

a reply to: Butterfinger

I like that! "A dollop of nightmares" Lol. I hope you won't mind if I rip you off and use that sometime?

originally posted by: 3n19m470

originally posted by: Greggers

originally posted by: NerdGoddess
You know what really gets me about these types of glorious creatures? How the hell does a spider DNA know what a Leaf cell structure looks like, and is like ahh yeah we'll go with that. That will work wonders for this guy. ?!?!?! Nature, how you so smart yo?

-Alee

It starts with an accidental mutation that allows the animal to blend in with its environment. This accidental genetic camouflage would be unlikely to so closely resemble a leaf after the initial mutation, yet gave the creature an advantage over spiders without the mutation. Over millions of years, that particular spider is more successful and passes its genetics on more often, and every time there is another mutation that brings it closer to blending in with its environment, that mutation is selected for by the natural threats and opportunities in the environment itself, until eventually we end up with this thing.

So that first accidental mutation, as well as countless generations of mutations after, didnt really look much like a leaf, right? It took a looong time before it got to this pretty convincing looking leaf, right?

So, that first accidental mutation, and all those that followed which didn't look much like a leaf... If it didnt look like a leaf then, how did it help it to survive better than its non mutated brothers and sisters? It seems like it would be more of a hinderance than a "force multiplier" or whatever... It wouldn't be useful for survival until the point where it actually looked like a convincing leaf. But according to you it survived across eons of time with this useless, protruding mutation sticking out of its body that served no purpose until the day that it, accidentally, started to look like a leaf.

Maybe you're right. I have no way of knowing. But it sounds a little fishy to me, personally.

As another poster correctly pointed out, there is no way to know how may genes or how many individual mutations this particular adaption took to evolve, nor how long it took.

However, in the scenario I provided, the initial mutation may not have looked much like a leaf, but it would have provided better camouflage than what belonged to its brethren without the mutation. Otherwise, it would not have provided a survivability benefit.

As far as it sounding fishy, I assure you that as a general rule, this is how natural selection works.

Spiders are pretty amazing, I've seen them look like lady bugs, flies, bees and crickets.

Here is a spider that looks like bird droppings lol...... imagine that on that leaf spider ....wha!
voices.nationalgeographic.com...

How about a spider that smells like bird droppings.... the foul smell help's it to attract prey and deter predators.
www.newscientist.com...

or

spiders looking like a bird nest.....
www.youtube.com...