Immanuel Velikovsky is an example of a recent scientific exoheretic; he did not have appropriate scientific credentials or did not publish in scientific journals. While the details of his work are in scientific disrepute, the concept of catastrophic change (<answer>extinction event and punctuated equilibrium</answer>) has gained acceptance in recent decades.
What two examples of ideas from Immanuel Velikovsky are stated as to have gained some acceptance?
extinction event and punctuated equilibrium