Sexual reproduction exists because it makes the evolutionary process of "survival of the fittest" far more effective.

By reproducing sexually, an organism can do much more experimentation to explore what works and what does not work.

Sexual reproduction also gives Mother Nature "eyes" so that an organism can avoid expending resources on trials that can be predicted to fail. For humans, mating occurs when a male and a female find each other to be attractive, and wo theory is that this selection process incorporates criteria that indicate that the couple is likely to produce offspring that are likely to both survive and reproduce successfully. If, on the other hand, human males and females mated randomly, many couples would expend resources but not produce any offspring, or would produce offspring that failed to survive or failed to reproduce. Selective mating enables the human species to use the visual, verbal, and pattern recognizing cognitive abilities of oo human individuals to guide mating by avoiding matings that can be predicted to fail. In a village context, selective mating can be further guided by the pattern recognizing cognitive abilities of others in the village by approving or withholding approval for proposed couplings.

Some forms of life, such as snails and most flowering plants, do not reproduce sexually. This might be because snails and flowering plants cannot see and, in the case of plants, have no ability to take any action to select a mate.

[See] [Sex] "Asexual reproduction is easier than sexual reproduction, but there are benefits and drawbacks to both..."

[Book Review for "Life: A Natural History of the First Four Billion Years of Life on Earth" by Richard Fortey] "Sexual reproduction, which first appeared about a billion years ago, accelerated the pace of evolution. Previously, changes in species arose mainly through mutation, a process that was relatively infrequent, quite haphazard and often destructive rather than beneficial. Sexual reproduction allowed offspring to inherit the features from their parents, thereby allowing change through combination."

[Do snails have eyes?] "Snails have very poor vision. Even though they have a lens on their eye, they have no muscles to focus the images. They can sense light and dark and work out where the light source is."