A snake could change and go look for its prey or someone will kill the snake and it would a prey it would take about hunderds of years
It depends on the species. The bigger the frog the longer it takes. A tiny tree frog could take a onth or two, and a huge bullfrog could take five months.
Environmental change and variation :)
When two groups of the same species are cut off from each other, they evolve from mutations and natural selection independently. Each one could evolve into a different species. For instance, let's say two populations of a species of bunny exist, one in a desert and one in the artic. The one in the desert would likely evolve into a bunny which could keep cool and blend into rocks and sand, while the population in the artic would likely evolve into a species which could keep warm and blend into snow. The one species of bunny would then become two.
Their environment changed and they could no longer survive.
Extinction. When a species fails to adapt, it dies out.
A common speciation event is called allopactric speciation. This is the geographic separation of a single species into two populations. Naturally, one could expect statistically different genetic variation to arise in these two populations and the environments may be different also. In any event, these two populations, after time, would be headed down different evolutionary roads.
Multi-cellularity evolved from mutations. This is how everything evolved throughout history. Random mutations that prove to be advantageous, and allow a species to continue to reproduce.
They can't. Once a species becomes extinct, it has reached the end of the line. It no longer exists, so therefore produces no more offspring. Thus, the theory that living species of today are descended from extinct species from long ago is untenable.
the snow leopard species will no longer excist and could effect the food chain for some animals
evee is one you could evolve into espeon
That Pokemon will evolve on Level 30. Glad that I could help.
Money had to evolve because barter could not cover every eventuality.