Lek mating females away from the hotshot. A manipulative experiment using the little bustard, "Tetrax tetrax", was done to test the various lek evolution models. The experiment involved varying the size and sex ratio of leks using decoys. To test whether or not the presence of a hotshot determined lek formation, a hotshot little bustard decoy was placed within a lek. After the fake hotshot was added to the lek, both male and female visitation to the lek increased. The hotspot model considers the female density to be the catalyst for the clustering of males. This model predicts that leks will form
Porphyria cutanea tarda Porphyria cutanea tarda Porphyria cutanea tarda (PCT) is the most common subtype of porphyria. The disease is named because it is a porphyria that often presents with skin manifestations later in life. The disorder results from low levels of the enzyme responsible for the fifth step in heme production. Heme is a vital molecule for all of the body's organs. It is a component of hemoglobin, the molecule that carries oxygen in the blood. Hepatoerythropoietic porphyria has been described as a homozygous form of porphyria cutanea tarda, although it can also be caused if two different mutations occur at the