noun. evolution on a large scale extending over geologic era and resulting in the formation of new taxonomic groups.
1. Noun, singular or mass Microevolution usually only happens on one or a few genes at a time in a small population, while macroevolution is a large-scale change of many things in larger groups, such as species diverging to create new species. 2. Verb, base form Some of the many small microevolutionary changes building up over time that sum to macroevolution include insects developing a new color, pesticide resistance, larger mandibles and resistance to cold.