Science project for school on dating
The reason can be to answer the students' own questions about how organisms live or care for their young.
Some students may enjoy displaying, with drawings, photographs, or even real specimens, all the living things they can find where they live.
Familiarity with the phenomena should precede their explanation, and attention to the concrete object should precede abstract theory.
Perhaps this is another instance in which following the course of history pays off.
Eventually, scientists produced and tested the theories and models that are used to explain people's observations.