Final answer:
Sexual reproduction is predominant because it creates genetic variation among offspring, which is critical for the survival and reproductive success of populations. This variation arises from processes like crossover and random assortment during meiosis, and despite the potential population growth advantages of asexual reproduction, the genetic diversity provided by sexual reproduction is likely why it's more prevalent.
Step-by-step explanation:
Why Does Sexual Reproduction Predominate?
While asexual reproduction allows for the production of genetically identical clones, most multicellular organisms—and many unicellular ones—reproduce through sexual reproduction. This method is evolutionarily successful, as evidenced by its widespread use across nearly all multicellular organisms on Earth. One of the main advantages of sexual reproduction is the introduction of genetic variation among offspring. This variation is vital for the survival and reproductive success of populations and arises from mechanisms such as crossover, random assortment of chromosomes during meiosis, and random fertilization. These genetic shuffles create unique gene combinations in not only multicellular organisms but also in many unicellular eukaryotic organisms that can or must engage in meiosis and fertilization. Despite the theoretical population growth advantage of asexual reproduction, since all individuals can reproduce, sexual reproduction's ability to produce genetically diverse offspring may account for its evolutionary success and prevalence.