Guppy Coloration Patterns

John Endler conducted two studies documenting the relationship between guppy coloration patterns in correlation to predation and sexual selection. Endler (1980) references his previous field study (Endler, 1978) in regards to coloration patterns present in the presence and absence of different predators. The relationship that was found there (Endler, 1978) was that in areas of high predation, coloring was less conspicuous and more closely blended to their background, whereas in areas of low predation, coloring was less cryptic. Endler (1980) had predicted this in his hypothesis that described guppies as being more cryptic when the guppy spot size, brightness, and color distribution are closely related to that of their surroundings, with the opposite being said for the more conspicuously colored and patterned. He hypothesized that this is due to higher predation on the more conspicuous specimens (Endler, 1980).
Endler’s (1980) greenhouse experiments were designed to mimic the guppies’ natural environment as close as possible by containing realistic pool sizes and depths, varying rock sizes and coloring, and natural predators in appropriately designed environments. The …show more content…
Observing natural selection in nature produces generally questionable results with numerous confounding variables. Only witnessing results in a lab setting does not support a hypothesis either. The two tests conducted by Endler (1980) showed a result in a controlled lab setting that was again mimicked and supported by field-testing. The basis of the field experiments was to see if the results that were observed in the lab were seen in nature as well, which would support the hypothesis. The field test methodology was closely repeated to that of the greenhouse trials and the results ended up showing the same pattern as predicted (Endler,