Survival is a very common theme. In the Stone Age, characters have to find food, shelter, and protect themselves from wild animals. For example, in 'Clan of the Cave Bear', Ayla has to learn how to hunt and gather in a new environment. Another theme is family and community. Whether it's a tribe or a clan, the relationships between the characters are important. They rely on each other for support and protection.
The relationship between humans and nature is also a big theme. Stone Age novels often show how early humans depended on nature for everything. They had to understand the seasons, the behavior of animals, and the growth of plants. In addition, the exploration of cultural differences can be a theme. Different tribes in the Stone Age might have had different languages, beliefs, and ways of life. This can create interesting conflicts and learning experiences for the characters in the novels.