Dominance (genetics)
![Peas in pods](/Images/godic/202502/10/Peas_in_pods_-_Studio0743.jpg")
![an autosomal dominant pattern.](/Images/godic/202502/10/Autosomal_dominant_-_en.svg0743.png")
![an autosomal recessive pattern.](/Images/godic/202502/10/Autosomal_recessive_-_en.svg0743.png")
![This Punnett square illustrates incomplete dominance. In this example, the red petal trait associated with the R allele recombines with the white petal trait of the r allele. The plant incompletely expresses the dominant trait (R) causing plants with the Rr genotype to express flowers with less red pigment resulting in pink flowers. The colors are not blended together, the dominant trait is just expressed less strongly.](/Images/godic/202502/10/Incomplete_dominance.svg0743.png")
This formula relies on a number of assumptions and an accurate estimate of the frequency of the recessive trait. In general, any real-world situation will deviate from these assumptions to some degree, introducing corresponding inaccuracies into the estimate. If the recessive trait is rare, then it will be hard to estimate its frequency accurately, as a very large sample size will be needed.