The Biological Advantage of Sexual Reproduction

Bring students to reflect on and discuss the question: Why should nature use/require the complex process of sexual reproduction when the simple process of asexual reproduction is available?

Have students review and list the complexities of sexual reproduction:

1. Producing a population of males and females
2. a unique form of cell division, meiosis, which separates pairs of chromosomes to produce eggs and sperm
3. another unique cellular process, fertilization, which combines the two sets of chromosomes.
4. Assuring that male and female come together for copulation and subsequent fertilization.

Again, why does nature do/demand all of this when numerous examples show that successive generations can be produced with simple cell division, i.e., asexual reproduction? Why is sexual reproduction so important to Nature?

Comparing sexual and asexual reproduction, have students observe that the one difference in outcome is VARIATION. Sexual reproduction leads to variation among the individuals of the next generation. Asexual reproduction does not. This changes the question to: Why is variation so important to Nature? Very simply, variation underlies the concept of evolution and is central to the concept of evolution. There could be no “fittest”, hence no “survival of the fittest” without variation. By “inventing” sexual reproduction, nature created the mechanism that enables evolution.