The theory of evolution (ToE) is that this is sufficient to explain all the diversity of life as we know it.
A sideways addendum if I may:
In the beginning the reproduction that takes place is a chemical imperative without any choice.
Got matter? Got energy gradient?
Electrons detach, attach in accordance with the electro-chemical state present in the surrounding stuff. Collections of atoms change their positions and detach/attach with other collections of atoms.
Then some configuration is achieved that fosters the gradients/matter to (more or less) produce copies of the original configuration.
As long as the supply of stuff and energy gradient lasts, perhaps millions upon millions of the self-reproducing configuration are produced, some with a minor difference, some with a major difference to the original. Configurations more/less productive, more/less efficient, reproduce at differential rates. Any matter/energy environment so suited continues the process.
So, survive reproduce repeat. Complex chemistry in continuous motion.
Life has happened.
Everything that has followed (pre-proto-cell walls, swallowing mitochondria, multi-cellularity, jaws, shells, phalanges, diamond rings, jobs, Hagen-Dazs Chocolate Ice Cream and postage stamps) are all the result of this original chemistry creating novel configurations of stuff that now seem to have taken on a strong zeitgeist to continue to reproduce to this day.
No purpose. No goal. Just the mindless propensity of chemicals to obey the one true god of the Universe — Physics.
And, before anyone asks, yes, Hagen-Dazs Chocolate Ice Cream can have a positive effect on reproductive success.