If males were motivated by, and taken to the point of, orgasm in the same way as females, those advantageous qualities would not be needed, since self-interest would be enough. Fertility
There are theories that the female orgasm might increase fertility. For example, it has been suggested that the 30% reduction in size of the vagina could help clench onto the penis (much like, or perhaps caused by, the pubococcygeus muscles), which would make it more stimulating for the male (thus ensuring faster or more voluminous ejaculation). The British biologists Baker and Bellis have suggested that the female orgasm may have a peristalsis or "upsuck" action (similar to the esophagus ability to swallow when upside down), resulting in the retaining of favorable sperm and making conception more likely. They posited a role of female orgasm in sperm competition. The observation that women tend to reach orgasm more easily when they are ovulating also has led to the suggestion that it is tied to increasing fertility. Evolutionary biologist Robin Baker argues in Sperm Wars that occurrence and timing of orgasms are all a part of the female bodys unconscious strategy to collect and retain sperm from more evolutionary fit men. This theory suggests that an orgasm during intercourse functions as a bypass button to a womans natural cervical filter against sperm and pathogens, and that an orgasm before functions to strengthen the filter. Desmond Morris proposed that orgasm might facilitate conception by exhausting the female and keeping her horizontal, thus preventing the sperm from leaking out.
It is a rare congenital stationary cone dysfunction syndrome, affecting less than 1 in 100,000 individuals, and is characterized by the absence of L- and M-cone function. BCM results from mutations in a single red or red–green hybrid opsin gene, mutations in both the red and the green opsin genes or deletions within the adjacent LCR (locus control region) on the X chromosome. Green cone monochromacy (GCM), also known as M-cone monochromacy, is a condition where the blue and red cones are absent in the fovea. The prevalence of this type of monochromacy is estimated to be less than 1 in 1 million. Red cone monochromacy (RCM), also known as L-cone monochromacy, is a condition where the blue and green cones are absent in the fovea. Like GCM, the prevalence of RCM is also estimated at less than 1 in 1 million.Cone Monochromats with normal rod function can sometimes exhibit mild color vision due to conditional dichromacy. In mesopic conditions, both rods and cones are active and opponent interactions between the cones and rods can afford slight color vision.According to Jay Neitz, a color vision researcher at the University of Washington, each of the three standard color-detecting cones in the retina of trichromats can detect approximately 100 gradations of color. The brain can process the combinations of these three values so that the average human can distinguish about one million colors. Therefore, a monochromat would be able to distinguish about 100 colors. Mammals
Until the 1960s popular belief held that most mammals outside of primates were monochromats.