Final answer:
The violation of Maynard Smith's first assumption of sexual vs asexual reproduction occurs when there are instances of multicellular organisms predominantly relying on asexual reproduction. This violation contradicts the rarity of such organisms. The prevalence of sexual reproduction is believed to be due to the variation it creates among offspring, which is important for the survival and reproduction of the population.
Step-by-step explanation:
Maynard Smith's first assumption of sexual vs asexual reproduction states that multicellular organisms that exclusively depend on asexual reproduction are exceedingly rare. The violation of this assumption occurs when there are instances of multicellular organisms that predominantly rely on asexual reproduction. While asexual reproduction is common among simpler forms of life, including bacteria and algae, the prevalence of sexual reproduction is believed to be due to the variation it creates among offspring, which is important for the survival and reproduction of the population.