Earth formed 4.6 billion years ago, and it wasn't until approximately 3.5 billion years ago that we estimate the first prokaryotic unicellular organism existed. The first eukaryote organism probably evolved 2 billion years ago, with the first multicellular organisms evolving about 1 billion years ago.
If 1 centimeter (cm) represents 10 million years (mya), then the 4.6 billion years of the existence of Earth would represent 4.6 meters (m), with the 4.6 m mark being the present.
This means that if we made a timeline with these dimensions, the origin of life would be at the 1.1 meters (110 cm) mark, the eukaryotic life forms appearing at the 2.6 m mark, and the first multicellular organisms around the 3.6 m mark.