By chance?

[no one]

Very well, fair enough.

[Mister Agenda]

The Sagan thing is very speculative, although the resemblance to a samurai mask is remarkable, the pattern reflects where muscles attach to the shell.

[BrianSoddingBoru4]

The Sagan thing is very speculative, although the resemblance to a samurai mask is remarkable, the pattern reflects where muscles attach to the shell.

Of course it’s speculative, but it’s also reasonable - a random mutation reinforced via selection.  Whatever organisms prey on these crabs, humans are the only ones likely to be deterred by a chance resemblance to a human face.

Boru

[arewethereyet]

Again the insults from the juveniles are a badge of honor, feel free to keep them coming

It’s the fact that a Perfect pair of ’s eyes appears on the butterflies wings,
ow many mutations did it take for that to happen? Was it just one eye first then d part of the second eye and then the irises after?
Then the rest of the second eye?
And what about how far they are spaced apart, in perfect proportion. What luck!!!

It only took 10,000 years for humans to utilize artificial selection to get, friendly, easily trainable, 25 pound dachshunds from 120 pound, wild, barely manageable, wolfs. All humans had to do, is start selecting for is, mutations for slightly more social wolfs (those that seemed to interact a bit more with humans), and slightly shorter legs, and breeding them.

Why do you think nature couldn't select for mutations on butterfly wings that slightly looked like the eyes of a more threatening animal, giving them a slight reproductive and survival advantage, thereby selecting them to continue to pass down their genes?

And by the way, those butterflies with 'perfect owl eye' wing patterns are not even 100% effective against being eaten by their predators. A decent percentage still get eaten. The eye patterns just give them a moderate survival advantage, not a complete survival advantage.

What is the biological mechanism that you think exists to prevent this process for butterflies, but allows it for wolfs and dogs?

I have seen this simplified into - have you ever seen a pack of wild poodles?

Having three couch potato Cavalier King Charles Spaniels I have to wonder that there could even be a smidgen of wolf left in them.  That is, until I saw them work as a pack to chase, corner and kill a few squirrels last summer.  After recovering from that mess I thought - yep, there's a tiny little bit of wolf left in there, if you squint you can see it.

[Mister Agenda]

Samurai crabs are not food crabs so humans don't prey on them anyway. Similar patterns have been found on fossil crustaceans.

[Fake Messiah]

Samurai crabs are not food crabs so humans don't prey on them anyway.

But humans do prey on them. Here's from an article

Samurai crabs do show us how quickly evolution works. What we have here is an instance of artificial selection, or a change in the physical characteristics of another species owing to the influence of humans.

Think of it this way, first comes the memorable sea battle, spawning legends. Next a fisherman finds a crab with markings on its back that look something like a human face. Does he eat it? No, that crab is thrown back. Now it has a survival advantage over crabs whose markings don't happen to look like anything to humans.

A cycle begins. Every generation that has a more human looking face stands a better chance of survival than the last. In time, perhaps over a thousand years, the originally random markings on Samurai crabs really do look like Samurais.

https://indianapublicmedia.org/amomentof...-crabs.php

[Aegon]

Wow, to think you digested all that and still think it happened by chance, tells me you will fall for anything.

What do you mean "by chance"? Your lens are too human-centric.

[zebo-the-fat]

Samurai crabs are not food crabs so humans don't prey on them anyway. Similar patterns have been found on fossil crustaceans.

There is a "face" on the Moon, has that evolved to keep humans off it?

[Rahn127]

Usually "chance" means an unknown probability.

There is a 50% chance of rain.
There is a chance that the woman I'm about to talk to will say yes when I ask her out for a date.
There is a chance that abiogenesis will be figured out in the next 50 years.

So when you say that something is by chance you are saying that the actual outcome or end result by which it happens is unknown at this time.

I would say that there are some processes that we don't know, but there are quite a few that we can demonstrate to be true to the best of our knowledge.

Being able to demonstrate truth means we can reproduce the results or we can reasonably show how we came to our conclusions by showing the evidence of our findings.

Evolution isn't by chance because we know the mechanisms by which life changes over time.

The universe, as much as we can tell, operates under the forces of physics. Physics isn't by chance either. We have slowly, over time, increased our knowledge about how bodies in motion react to each other through gravitational forces.

We observe nature and discover what appears to be physical laws of motion. In every discipline of science we observe the world around us and make our conclusions about those observations, supplying evidence to support our conclusions.

We welcome anyone to prove our conclusions wrong.
Our entire system of peer review hinges on it.

Show your work. Provide your evidence and let others attempt to rip it to pieces. Walk the gauntlet and join every other scientist in the world.

Chance rarely has anything to do with it.

[no one]

Rahn, you'd have a better chance beating that information into a boulder with your forehead, than to get tater tot to understand even the tiniest fraction of it.