This is the oldest fossil ever found belonging to the line that leads to us.
Phylogeny is the biological development and history of an organism or its class. Paleontologists have been researching the class Mammalia’s phylogeny for some time, particularly its trajectory from tiny rodent-like creatures in the late Triassic 200 million years ago, to modern-day humans. There are currently around 5,000 mammals on the planet, and it's a very diverse group at that.
Evolutionary biologists generally agree that humans evolved from a bacteria-like ancestor, rather than a viral one. But what if we're chemically connected?
What would life look like if it had evolved from viruses instead of bacteria? Maybe it’s what you see in the mirror, jokes Bill Nye – before setting the record straight. Most evolutionary biologists agree that bacteria-like organisms are the ancestors of humans. About two billion years ago, eukaryotes forked off from bacteria, eventually giving shape to humans, animals, plants and fungi. It’s anyone’s guess what kind of organism you’d get from the evolution of viruses but, says Nye, it’s very reasonable that there is a common chemical ancestor for both viruses and bacteria, and if someone wanted to roll up their sleeves, it would be possible to prove it. Bill Nye's most recent book is Unstoppable: Harnessing Science to Change the World.