Mexican Terta fish (blind cave fish)

[Wally]

So I was reading a recent news story about a certain species of fish, namely the Mexican Tetra, which has lost its ability to see due to living in a dark cave environment for so long. I have a question about how evolution works in cases like this.

Random mutations cause animals to change over time. Natural selection then selects which ones are best adapted to their environment. The ones that are best adapted will live longer and pass along more of their genes.

My question is this: How did natural selection “know” that these fish no longer needed their eyes? What is the benefit of losing your eyesight in a dark environment? How would your chances for survival be better, thereby giving you more opportunity to reproduce and pass along your genes, by losing your eyesight?

In other words, why would an animal lose one of their senses simply because it is no longer necessary for daily life? If mutations are random, and losing your eyesight has no effect one way or the other on your odds of survival in a pitch-black environment, why would nature select those that have randomly lost the ability to see?

If I start wearing earplugs today, and all my offspring wear earplugs, and all their offspring wear earplugs, is it true that eventually my descendants would start to lose their hearing just because they don’t use it anymore?

Wally

[Furrowed Brow]

I was just trying to get my brain around why blindness would be selected instead of the ability to see.

All one has to have is a good imagination.... the possibilities are limitless.

I do believe Fisherking is slowly mastering irony.

But letting the irony go over my head for one moment. Old FisherK has a point. The first part of forming an hypothesis requires the application of some good old imagination. However you then have to back your imagination up with sound thinking and evidence, whilst seeking ways to falsify the hypothesis. A methodology followed by evolutionary theory.

The implication of Fisherking's ironic dig is that any old thing can be thunk up to explain anything in order to preserve evolutionary theory. We have already had threads defending evolutionary theory. So I'd like to turn this point around.

What is wrong with accepting that nature is way more flexible, subtle, and makes way more strange turns, than the imagination of the average creationist will allow? What is the flaw in accepting as an hypothesis that blindness can be selected for? That it is an ad hoc fix to evolutionary theory. Hardly. That evolutionary theory is unfalsifiable. False again. All these points we have debated many times. Fisherking’s irony is just like too.....ironic.

[realthinker]

I was just trying to get my brain around why blindness would be selected instead of the ability to see.

All one has to have is a good imagination.... the posibilities are limitless.

They are indeed! The number of environments that affect the viability of an organism and the usefulness of particular genetic attributes is vast. And without knowing the exact contribution of a genetic attribute it's hard to predict where one of those attributes becomes a factor in species survival.

[byofrcs]

I was just trying to get my brain around why blindness would be selected instead of the ability to see.

All one has to have is a good imagination.... the posibilities are limitless.

They are indeed! The number of environments that affect the viability of an organism and the usefulness of particular genetic attributes is vast. And without knowing the exact contribution of a genetic attribute it's hard to predict where one of those attributes becomes a factor in species survival.

So vast that not even God can predict the environment which is why most modern theists are happy that God has used Evolution. It is only Americans and Muslims that on average have a problem with that (e.g. see here etc etc etc). That is so funny really.

[Cathar1950]

I was just trying to get my brain around why blindness would be selected instead of the ability to see.

All one has to have is a good imagination.... the posibilities are limitless.

They are indeed! The number of environments that affect the viability of an organism and the usefulness of particular genetic attributes is vast. And without knowing the exact contribution of a genetic attribute it's hard to predict where one of those attributes becomes a factor in species survival.

The easy part about rejecting evolution is you don't really need an imagination as they replace understanding with myth, stories and dogma.
I tend to think what does exists are emergent qualities or attributes of genetic influence and not like it is a fixed set of presupposed information. At this point we don't even know all the emergent attributes or possibilities of various genetic combinations. Not even nature seems to have found or used them all. We have legs or eyes because that is what a particular combination of genetic codes produce and they were found useful or beneficial. In other words I am wondering if genes even know(or it is known) what the the outcome will be until it is produced. Bit by bit they are shaped or selected as they help deal with their environments or responses to change both in the organism and its environment.
I am not making any kind of declaration but more trying to grasp how it may work.
This vague idea I have is looking at the outcome of genetic codes as accidentally emergent qualities that are not aimed at any outcome as much as they produce something we might call legs or eyes that have been shaped by their use and biological history.
When we here the criticism that they couldn't possible be produced by chance they really have it backwards because the chances that they turn out that way is about 100% because that is how they developed and turned out. There is no aim, except to survive, only result. The variations have been built on over billions of years. It looks like trial and error only we don't see the errors as they don't survive or go unnoticed and we don't notice all the outcomes.
I could use a little help here guys and gals as I am trying to formulate some understanding of what seems to be happening and I am way over my biological understanding even if I did spend years in college studying biology and such things before I went postal and took up history, psychology, sociology(more cultural and pschological sociology), philosophy and religion.

[Cathar1950]

I do believe Fisherking is slowly mastering irony.

But letting the irony go over my head for one moment. Old FisherK has a point. The first part of forming an hypothesis requires the application of some good old imagination. However you then have to back your imagination up with sound thinking and evidence, whilst seeking ways to falsify the hypothesis. A methodology followed by evolutionary theory.

The implication of Fisherking's ironic dig is that any old thing can be thunk up to explain anything in order to preserve evolutionary theory. We have already had threads defending evolutionary theory. So I'd like to turn this point around.

What is wrong with accepting that nature is way more flexible, subtle, and makes way more strange turns, than the imagination of the average creationist will allow? What is the flaw in accepting as an hypothesis that blindness can be selected for? That it is an ad hoc fix to evolutionary theory. Hardly. That evolutionary theory is unfalsifiable. False again. All these points we have debated many times. Fisherking’s irony is just like too.....ironic.

It didn't go over my head as much as I refused to openly acknowledge his rather misplaced dig. I did sense some sarcasm.
I just acknowledged his lack of the need for imagination.