Incidence of colourblindness among four endogamous nomadic groups: an example of natural selection
TLDR
The findings support the differential selection hypothesis for this loci of Post (1962) and Pickford (1963) and the implications of the loss of the colourblind gene has been discussed in the light of nomadic way of the Nandiwallas, and also of their small effective population sizes.Abstract:
Incidence of colourblindness among 1501 (945 males and 656 females) persons belonging to four nomadic Mendelian isolates, the Nandiwallas of Maharashtra, India, has been reported. Out of the four groups, three lacked the gene for colourblindness, while in one group the incidence was rather low (0·3 per cent). Our findings support the differential selection hypothesis for this loci of Post (1962) and Pickford (1963). 110 families with 334 children were examined for the inheritance of this trait. All matings except one were of the type normal × normal and produced all normal children; the one family of the type father colourblind × normal mother, also had all the six children with normal colour vision. The implications of the loss of the colourblind gene has been discussed in the light of nomadic way of the Nandiwallas, and also of their small effective population sizes.read more
Citations
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Prevalence of colour blindness in young Jordanians.
TL;DR: This population-based investigation is meant to fill a gap in this field of colour blindness in Jordan, by randomly selected and tested for congenital red/green colour blindness, by using Ishihara pseudo-isochromatic colour plates.
Journal ArticleDOI
Congenital Color Blindness in Young Turkish Men
TL;DR: Higher percentages of color blindness were found in regions with a lower education level and more consanguineous marriages, and these ratios were higher than other reported samples from Mediterranean Europe.
Prevalence of congenital color vision defects among school children in five schools of Abeshge District, Central Ethiopia
Mulusew A,Yilikal A +1 more
TL;DR: The prevalence of congenital color blindness in this study is similar to the previous two studies among Ethiopians, and early school screening for color vision defect is recommended.
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Genetics of Castes and Tribes of India: A Review of Population Differences in Red and Green Colour Vision Deficiency in India
TL;DR: The validity of the hypothesis of relaxation of selection among different ethnic groups explains to some extent the status of colour blindness in tribal population groups as compared to other ethnic groups particularly caste groups, but still it has to be substantiated with further data.
Journal ArticleDOI
Natural selection and colour blindness: fresh data on Indian castes
TL;DR: The results, in general, are compatible with the Post and Pickford's hypothesis of differential selection for colourblindness.
References
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Journal ArticleDOI
Population differences in red and green color vision deficiency: a review, and a query on selection relaxation.
TL;DR: Prevalence rates of red and green color deficiencies are tabulated for all the population samples found in the literature as estimated by testing males with the Ishihara color cards, finding that among the lowest rates are those of the aborigines in Australia, Brazil, Fiji, and North America.
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A Review of the Inherited Defective Colour-Vision Variability and Selection Relaxation among the Indians
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The Incidence of Inherited Defects of Colour-Vision in Eight Endogamous Groups of Maharashtrian Brahmins
TL;DR: Data on defective sex-linked colour vision has been reported on 1580 male subjects drawn from eight endogamous groups of Maharashtrian Brahmins, with a great deal of heterogeneity in the groups investigated.