At which level of interaction does life first appear?

Life firstly evolved at the cellular level. Prokaryotes were the first living organisms.

Explanation:

The earliest known form of life is believed to be produced in hydro thermal vents.

Scientists believe that the early cells were very simple perhaps it was just a molecule protected by a wrapper. Evidence shows that life on the Earth initiated by the formation of a molecule made up of amino acids i. e RNA. RNA has the ability to reproduce as well as it is involved in the making of proteins. Eventually, the RNA evolved into DNA due to RNA's unstable form. With the passage of time the RNA or DNA started protecting itself inside lipid membranes. Hence, Cells were produced and this started the beginning of life about four billion years ago. The first type of cells to be evolved were simple and termed as the prokaryotic cells.