Comet 67P has the building blocks of life — smells like mothballs and almonds

Giant meteorite strikes in Earth's distant history may have helped form continents | Space.com Forums

This report and following posts demonstrate much catastrophic bombardment for Earth from 4.5 to 2.5 Gyr ago. Detailing the steps needed to convert organic molecules found in a comet, what happens to those molecules upon impact with Earth, and evolving into life later, seems difficult, especially now with the potential for many more impacts taking place on Earth from 4.5 to 2.5 Gyr ago. There would be plenty of catastrophic destruction events operating on Earth during the Precambrian.