The common mantra states that evolution is a gradual process that takes a great deal of time to occur. (That is one reason they go on a Darwin jihad against people who dare to show scientific evidence for a young Earth.) Evolution is so slow, you can't see it. (Unless you think along the lines of Stephen Jay Gould, who rejected traditional evolutionary thinking and preferred "punctuated equilibrium"; evolution happened so fast, you missed it.) Actually, neither position has evidential support.
In all of these instances, the speedy changes have nothing to do with the production of any new genes by mutation (the imagined mechanism of molecules-to-man evolution), but result mostly from selection of genes that already exist. Here we have real, observed evidence that (downhill) adaptive formation of new forms and species from the one created kind can take place rapidly. It doesn’t need millions of years.
Shouldn’t evolutionists rejoice, and creationists despair, at all this observed change? Hardly. Informed creationists have long stressed that natural selection can easily cause major variation in short time periods, by acting on the created genetic information already present. But this does not support the idea of evolution in the molecules-to-man sense, because no new information has been added.You can read the rest of this in context, along with the comments about fish, finches, lizards, mice and other critters at "Speedy Species Surprise". And you might like the short video, below.