Finches adapt to the new conditions such as drought by changing the size, shape and depth of their beaks. Beak morphology varies according to drought conditions. Since after the drought, vegetation dries out and the hard, big, tough seeds remain, only the finches with deep beaks will survive. Finches adapt via their beaks to different foods sources and different local conditions.
I think the answer is molars
I believe it will be 200,000 years
Earth's crust is generally divided into older, thicker continental crust and younger, denser oceanic crust..The crust is made of solid rocks and minerals.
The mantle lies between Earth's dense, super-heated core and its thin outer layer, the crust. The mantle is about 2,900 kilometers (1,802 miles) thick, and makes up 84% of Earth's total volume.
The core lies beneath the cool, brittle crust and the mostly-solid mantle. ... Earth's core is the very hot, very dense center of our planet. The ball-shaped core lies beneath the cool, brittle crust and the mostly-solid mantle.1