How do organisms form carbon films? Organisms turn into rock.
Residue is left on rocks when organisms decay.
Hollow forms are left in sediment by decaying organisms.
Organisms leave evidence of their activities, such as footprints.

Simplest answer?

The spermists believed that: the male made the only hereditary contribution to the offspring the male and female traits were blended in the offspring the female made the only hereditary contribution to the offspring the male and the female made equal contributions to the next generation