http://www.ineffableisland.com/2013/12/cavefish-demonstrates-rapid-evolution.html
I always wondered about these fish. I still wonder if you remove a breeding pair of such fish from the cave, are their offspring blind, too?
metatron
Rapid Evolution: Blind Cave Fish
by metatron 12 Replies latest jw friends
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snare&racket
Rapid evolution still requires mutation and natural selection, there is no reason it cant happen faster (e.g. hundreds of thousands of years for vision), though it is more probable that lots of time is required (Millions of years for vision). So no they wouldn't with a very high probability develop it quickly and certainly not the first offspring. For them to see would require multiple mutations leading to vision, all happening at once ... And it would be irrelevant to the enviroment if it was their offspring, it would be random chance in the mutations and it would only be one offspring, what is the chance of all that happening at the same time to the second offspring? Insurmountable! Again these are all realms of probability that are so unlikely due to the way you asked the question.
i dont think you understand evolution buddy, no offence.
(by the way I assumed you meant offspring as direct descendants....if by offspring you mean some 'later' generation, then that is just normal evolution. The idea of rapid evolution or 'leaps' is rolling the dice several times over and getting the mutation most beneficial in little time, as opposed to a long time, but not in one generation!)
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nonjwspouse
The fish is the "lost Sea" underground cave fed by a water spring have no eyes. It's pretty amazing. At some point an earthquake must have closed off the access to this lake in the cave so they are unble to get out. How many years for the fish to develop with no eyes, I imagine was a very, very long time.
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cofty
The rule in evolution is "use it or lose it".
Whan a population find themsleves in a dark environment there is no selective pressure to maintain the genes for making eyes. If an individual suffers a mutation that damages its ability to make effective eyes it will not be at a disadvantage compared to other individuals who have excellent eyes but no light to make use of them. The blind fish will be just as likely to pass on its faulty gene to future generations. Further mutations are likely to accumulate in the population and the genes to make eyes eventually become pseudogenes.
The time since a pseudogene last did any useful work can be estimated by the number of mutations it has suffered. Imagine walking through an abandoned suburb. Some houses look good apart from the long grass, others have broken windows, missing roof tiles or no roof at all. Broken genes like the ones we still have to produce vitamin C are similar.
Remember that the many genes to make eyes are controlled by other regulatory genes. There is a gene called "eyeless" that instructs the other genes to go ahead and make an eye. If "eyeless" suffers a mutation an individual can lose its sight in one generation. Experiments with "eyeless" genes taken from mice and implanted in fruit flies have resulted in extra eyes on legs and antennae.
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wallsofjericho
if you take blind fish out of their blackened environment and put them in illuminated waters, they will be a such a disadvantage to predators that they likely would not ever survive to reproduce in that habitat.
Thus "natural selection" will have occured exactly as it has always been predicted.
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PelicanBeach
"Experiments with "eyeless" genes taken from mice and implanted in fruit flies have resulted in extra eyes on legs and antennae."
Cofty were those extra eyes connected to the animal's/insect's brain enabling them to see or were they only external spots/tissue?
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Simon
One really neat thing is that the genetic blueprint for an earlier artifact is 'remembered' in the DNA and may lie dormant until it is needed. So the initial adaptation can take longer than sunsequent reversion.
Do creationists actually believe that God made blind fish to live in that one cave I wonder?!
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cofty
Pelican - No IIRC they eyes were not connected by optic nerves
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besty
Do creationists actually believe that God made blind fish to live in that one cave I wonder?!
would they accept evidence that indicated the cave was formed more than 6000 years ago?
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nonjwspouse
And then there is the Sherpa Phenomenon,
http://evolution.berkeley.edu/evolibrary/news/101001_altitude
