These genes are certainly not observed in extinct organisms. (firstthings.com)
It is now possible to perform whole - genome shotgun sequencing as well as capture of specific genomic regions for extinct organisms. (science.sciencemag.org)
And so the microbial world was delegated to an invisible world in the 18th century — as natural philosophers turned to questions about the evolution of plants and animals, and the geologic structures that contained fossil remains of extinct organisms. (discovermagazine.com)