Post 14: An Update to the Tree of Life🌳
Published:
Where do we stand compared to the rest of life forms? Well, right there among the opisthokonts, a group that includes animals, fungi, and a few other curious creatures. Biologists love classifying everything into groups to get a general idea, which is why we have the “tree of life” based on the DNA we’ve sequenced so far.
This tree was created by the French scientist Bacille Diderm, who drew representative organisms for each group, showing the life forms whose morphology we know (i.e., we’ve actually seen them). Life forms that we only know about because we’ve sequenced their DNA are marked with a DNA icon. For example, eukaryotes are a well-known group compared to archaea.
There are many versions of the tree of life, but this is, to my knowledge, the most up-to-date. It also illustrates that more than half of the biodiversity we know comes only from DNA sequences.
The most incredible part? In the case of eukaryotes, we’ve only sequenced about 1% of the species we know! For the ~85,000 species of bacteria and archaea we currently know, it’s even worse since only a handful have been successfully cultured.
And in case you’re wondering, yes, Eukarya are placed deep within Archaea in the tree due to the Asgardian archaea, which, according to recent phylogenetic analyses, put us at the Order level within the phylum Asgardarchaeota as per recent studies.
Refs:
- The PDF version of the tree of life
- The articles Bacille used for his drawings
- Percentages on sequenced biodiversity
For more on the tree of life, described from the perspective of microbes: