Talk of Darwin marrying his first cousin, and how many of the children that they have had usually get sick or die as infants.

At the beginning of the film, when the native children are taken back to their island, you see the children nude from the backside running back to their tribe (nothing sexual).

During a scene to demonstrate the reconciliation of their marriage, Charles and Emma are shown in bed together at times embraced. There is no explicit nudity, nor sex, but it is evident that they are not dressed under the sheets. Emma's nude back is shown from several angles.

Depiction of pigeons being killed for scientific experiments.

There is a scene of a fox killing a hare in the wild which upsets one of Charle's children.