Reginald Punnett And The Punnett Square
Reginald Crundall Punnett was born in June 1875 in Tonbridge, Kent, England. He was educated at Clifton School, Bristol, and Gonville and Caius College, Cambridge, which he entered as a scholar in 1895.7 Later, he attended Naples Zoological Station in Italy, Heidelberg University in Germany, and began moving up the academic ladder. Punnett was associated with C. Bateson (an English Botanist) and knew he was using Mendel’s work as part of his research. Punnett wrote Bateson a letter suggesting that his expertise in nutrition could help him analyze coat-color inheritance in mice. Bateson replied by offering a partnership in his breeding experiments.
Punnett was enthused and refused Bateson's salary offer. Bateson and Punnett studied Mendel's work on peas and coined the term partial coupling. The analysis of the various ratios that characterized Mendelian inheritance was much facilitated by Punnett's simple square diagram showing how gametes combine to make zygotes or sometimes how genotypes at two loci combine to make zygotes.8 As Punnett published more examples of grids, his first diagram was a simple two-by-two and then a four-by-four diagram of flower petals. As he analyzed more plant examples, his grids became more complex, like a nine-by-nine grid with diagonal lines within it. In his second edition of his Mendelism, he used a different format showing 9:3:3:1. The squares he created vary in size, and some squares were within squares (smaller into larger ones). He called the squares’ construction chessboards because the diagonal, crisscrossed lines and capital and lowercase letters appear within the diagrams.
Punnett did much work and published it in books. He contributed by comparing anatomy, butterfly mimicry, and the genetics of fowl, rabbits, and sweet peas based on Mendel’s research. He defended Mendel’s work when many scientists frowned upon it, because Mendel presented his research and later Darwin presented his work on evolution. Darwin’s work became more widely discussed than Mendel's. He did much to introduce genetics to the public and to commercial breeders and, in so doing, helped create opportunities in biological research that geneticists today enjoy.9 Darwin’s papers were popular among scientists who attended his presentation, whereas Mendel’s papers were stored and some were burned when he died.
Mendel and Punnett studied genes in plants and identified dominant and recessive alleles. Future research on the genetics of more plants, animals, and humans has revealed more of what biology has discovered. Marriages within families have been an ongoing practice since the beginning of man. In the Bible, when man first existed, he married his sister, and sisters married brothers. Then, during Moses’s time, God commanded that close-relation marriages be forbidden. In general society, these marriages are frowned upon. These inter-generational marriages created diseases and sicknesses, which led to mutations. The Ptolemy dynasty, cousin marriages, and tribal marriage continue to practice close family marriages.
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