Cells in complex multicellular organisms form thousands of different shapes.

In a complex organism like the body, cells are continuously differentiating.

Simple creatures are much more common than complex organisms.

It is too young a world for complex organisms to have evolved.

The difficulties of recovering complex organisms from a frozen state have been long known.

With selection, evolution can also produce more complex organisms.

All governments, no matter how small, are complex organisms with their own codes and instincts.

But the human is such a complex organism that there must be other explanations, too.

Well, he thought, a justice ministry responsible for an entire planet was, by its very nature, a huge, complex organism.

He has been more successful than any other creature and is, as a result, the most complex organism on the earth.