We can see a gradual change in the fossil record, from the earliest bacteria fossils of 3.8 billion years ago, to the simple single-celled bacteria which formed ecosystems 3.5 billion years ago, to Archaebacteria fossils 2.9 billion years ago, to multi-cellular eukaryotes fossils of 1.7 billion years ago to fossils of higher algae 1.2 billion years ago, to the "Ediacaran fauna" (the first fossils of large organisms) 650 million years ago, to the Cambrian fossils of about 500 million years ago.
(We; can see; a gradual change in the fossil record) (the simple single-celled bacteria; formed; ecosystems; T:3.5 billion years ago)
We the simple single-celled bacteria
can see formed
a gradual change in the fossil record
ecosystems T:3.5 billion years ago