One of the most interesting aspects of the current studies on the history of evolution is the growing attention in exploring its role and scope in non-scientific fields, for example, in education. Some scholars have explored how the theory of evolution was introduced to the classroom and when the efforts to include the topic in textbooks began.

In the Mexican scene, the teaching of evolution has undergone many changes in the last few decades. Starting by posing the question: why evolution was introduced in the curriculum of primary schools until 1974? Our study is focused on a comparative analysis of the content of evolution in primary and secondary Mexican biology textbooks since 1974, from a HPS perspective but it also explores the social tensions behind the introduction of one of biology's most fundamental ideas into basic education.

Interestingly enough, in Mexico since 1954 textbooks for basic education are free and universal. This means that every Mexican child from 6 to 15 years old receive the same educational material (2.7 million copies of every subject are published every year), making textbooks a truly influential element in Mexican education.

Our results will shed light into: 1) the content of evolution in biology textbooks since 1974, 2) the dominant values and ideology of the era in which each different textbooks was written, 3) how certain social, political and scientific dynamics occurring in the Mexican scene from late Eighteenth century have had a direct impact in basic school biology.