Original sentence: About 500 million years ago, plants and fungi colonized the land, and were soon followed by arthropods and other animals.Amphibians first appeared around 300 million years ago, followed by early amniotes, then mammals around 200 million years ago and birds around 100 million years ago (both from "reptile"-like lineages).However, despite the evolution of these large animals, smaller organisms similar to the types that evolved early in this process continue to be highly successful and dominate the earth, with the majority of species prokaryotes and the majority of animals insects.The first multicellular organisms may have evolved from species similar to slime moulds, which live as single cells but aggregate as part of reproduction
Edited sentence: About 500 million years ago (mya), plants and fungi colonized the land, and were soon followed by arthropods and other animals.Amphibians first appeared around 300 mya, followed by early amniotes, then mammals around 200 mya and birds around 100 mya (both from "reptile"-like lineages).However, despite this apparent progression, the smaller forms of life that evolved early in this process continue to be highly successful and dominate the earth, with the majority of species prokaryotes and the majority of animals insects.The human genus arose around 2 mya, with the earliest anatomically-modern humans developing in Africa 100–200 thousand years ago