4 SEXES

4 SEXES - DOUBLE MALE, DOULBE FEMALE

Sources and background:
Huynh, L., Maney, D., & Thomas, J. (2010). Chromosome-wide linkage disequilibrium caused by an inversion polymorphism in the white-throated sparrow (Zonotrichia albicollis). Heredity, 106 (4), 537-546 DOI: 10.1038/hdy.2010.85
Joron, M., & Whibley, A. (2010). Stripes, sex and sparrows: what processes underlie heteromorphic chromosome evolution? Heredity, 106 (4), 531-532 DOI: 10.1038/hdy.2010.106
Matsunaga, S. (2009). Junk DNA promotes sex chromosome evolution. Heredity, 102 (6), 525-526 DOI: 10.1038/hdy.2009.36
Moore, R. (2008). Sex chromosome evolution: A 'missing link' in the evolution of sex chromosomes. Heredity, 102 (3), 211-212 DOI: 10.1038/hdy.2008.115
Tuttle, E. (2003). Alternative reproductive strategies in the white-throated sparrow: behavioral and genetic evidence. Behavioral Ecology, 14 (3), 425-432 DOI: 10.1093/beheco/14.3.425
Thorneycroft, H. (1966). Chromosomal Polymorphism in the White-Throated Sparrow, Zonotrichia albicollis (Gmelin). Science, 154 (3756), 1571-1572 DOI: 10.1126/science.154.3756.1571
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