Why would evolution speed up when a small group of organism migrates to a new environment?

Is there any species that went extinct in recent years due to natural causes (not caused by human interaction). if so, what caused it?

As scientists have investigated evolution from a variety of fields, they have found that some of darwin's orginal ideas were inaccurate or incomplete. t explanation provided by evolution was updated each time to reflect the new information they found. what does this suggest about the theory of evolution? it has become a stronger and clearer theory as new information is collected.

The pelican's beak is adapted for in .