Kevin Kelly:

Because of the circle, no organism is privileged with being above another. A circle has not top. We humans are somewhere in the lineup, but where depends on how you turn the chart. This circle of life also better captures the idea that all living organisms today are equally evolved. By definition, any organism alive today (shown on the outer rim) can boast an unbroken chain of ancestors who have survived the same number of years, 4.5 billions years. The snail, fern, clam and mite have all undergone an equally long path to now. They are all the results of 4.5 billion years of evolution. The fern’s 4.5 billion-year answer to how to survive is to steal energy from the sun; the snail to steal it from the fern; the mite to steal it from the snail, and the deep vent clam, to steal it from the heat of the earth.

Though our intelligence, cellular complexity, or phenotypic traits are far from equal, all organisms alive today are equally evolved. Each species has been down a 4.5 billion-year path that led it to the niche it fills today.