effects - in other words, the small effects of a wide number of variants at specific loci add together to produce a large, combined effect on the overall phenotype of the individual. They also acknowledged the presence of large but rare mutations that have a large effect on phenotype. This study showcases the intricacy of genetic architecture by providing an example of many different SNPs and mutations working together, each with a varying effect, to generate a given phenotype. Other studies regarding genetic architecture are many and varied, but most use similar types of analyses to provide specific information regarding loci involved in producing a phenotype. A study of the human immune system in 2015 uses the same general concepts to identify several loci involved in the development of the immune system, but, like the other studies outlined here, failed to consider other aspects of genetic architecture, such as environmental influences. Unfortunately, many other aspects of genetic architecture remain difficult to quantify. Although there are a few studies that seek to explore the other aspects of genetic architecture, there is little ability with current technologies to link all of the pieces together to build a truly comprehensive model of genetic architecture. For example, in 2003, a study of genetic architecture and the environment was able to show an association of social environment with variation in body size in Drosophila melanogaster. However, this study was not able to tie a direct link to specific genes involved in this variation. See also Ambidirectional dominance References External links Line-Cross Analysis Genotype-Phenotype Maps The Rise of Genetic Architecture Genetics