Perhaps perfection was the wrong word to use; however if the universe can be identified as perfect (maybe it can't?), would it be possible to become more evolved than the universe itself? If the universe sets the pace, there would likely be an evolutionary cap while the universe itself is growing.
This would suggest the most advanced species could on some level be considered perfect, at least for the time being.
But if life can set the pace independent of the universe who knows what is possible? But I agree in this case perfect is definitely the wrong word to use.
How about cloning? A being could hypothetically revive itself for an infinite number of times. This could be considered immortality to some. It's cheating because it's not evolving past death, only allowing the genes to continue to be born.
Since growth is based on experience as well as genetics, it's possible each clone will still be unique and evolve in a sense.
Stephen Hawking had some interesting ideas about a species bioengineering it's evolution on his documentary "into the universe".
In this case a species could hypothetically defeat whatever genetic codes cause death. This wouldn't end evolution though, as this species can evolve any time it likes through genetic manipulation.
A species like this could search the universe for new molecules which can be fitted into genetic code to create new forms of life.
It would only be limited by the species' current understanding of genetics, and which molecules are available.
I think these are all realistic ideas since humans are experimenting with similar things already. If the universe has as much life as it does stars, I think it's possible another species has already done this.
Disclaimer: All Entheogens and other research materials are not for Human consumption! I have researched by text the effects of consuming such things in case of accidental consumption. I have never actually consumed any of the materials I speak about and it should be assumed I'm speaking hypothetically. I have a wild imagination.