Evilution Theory?

Question

Why have the Darwinein finches NEVER evolved but only adaptations of the beak from diet are observable---finches continue to be finches after all these years?

Answer 1

You miss the point.

Adaptation IS evolution (if it is adaptation of the entire species through the propagation of genes throughout the species).

The entire point of Darwin's finches is that noticeable evolution, can occur in a relatively short amount of time. Larger amounts of time (*far* larger than the 170 years since Darwin encountered them), produce larger changes.

In fact, it isn't just beak length, but they have become distinct *species* of finches ... they do not interbreed.

They continue to be called "finches" only because that's a name given to a certain family of birds that contain *many* different species. It's just a name. Were you expecting them to become an entire different family?

So other than that, I have no idea what you are expecting to have happen in "all those years" (170 years?).

Answer 2

Are we dealing with a creationist here?
In the amount of time that we have been observing finches, we've only been able to observe adaptation, not evolution, that is true. The theory of evolution has often been criticized by religious groups because we can't "see" things, such as humans, monkeys, or whatever, evolve. It's also been pointed out that it is "just" a theory.
The fact that evolution is just a theory is actually its strength. Theories in science are falsifiable models, based on which one can make falsifiable predictions of certain things.
The fact that finches have beaks whose length changes in response to environmental changes is often cited as "the" proof that evolution occurs, due to the fact that this is what inspired Darwin's famous theory. However, in today's science, this example is dated, and mostly irrelevant. A more concrete example of evolution is, for example, bacteria evolving antibiotic resistance in the last 20 years, this is clearly visible, and has occured only in recent history, so we've been able to track it.
We can also measure the differences in the DNA of related organisms, and we find that organisms that are closely related, like people and chimps, have very similar DNA, even in genes conserved from yeast to humans, whereas yeast would have a much more different DNA sequence of the same gene, encoding for the same required protein.

The short answer to your question is quite simply finches are still finches because we haven't been watching them for long enough.

Answer 3

Thanks for the question about the Galapagos finches.

Now take a look at the Galapagos marine iguana. It is very different from any other lizard. You might say that after all these years, it has ceased being whatever it was before.

Now go look in the mirror. You're not a monkey! It took millions of years, but congratulations, you're a human being.

Answer 4

Because it obviously works for them, so they don't need to.