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Effects Of Mortality Risk And Growth On A Model Of Reproductive Effort: Why The Shine And Schwarzkopf Model Is Not General, Peter Niewiarowski, Arthur Dunham
Effects Of Mortality Risk And Growth On A Model Of Reproductive Effort: Why The Shine And Schwarzkopf Model Is Not General, Peter Niewiarowski, Arthur Dunham
Dr. Peter H. Niewiarowski
Using data and reanalysis of a model published by Shine and Schwarzkopf (1992), we reject the two unsubstantiated assertions made by Shine et al. (1996) about modeling the evolution of reproductive effort in squamate reptiles.
Analysis Of Long-Term Selection (28 Generations) For Reproduction, Growth, And Carcass Traits In Swine, Wan-Ling Hsu
Analysis Of Long-Term Selection (28 Generations) For Reproduction, Growth, And Carcass Traits In Swine, Wan-Ling Hsu
Wan-Ling Hsu
The objectives were 1) to estimate responses from 28 generations of selection for increased pigs born alive (BA) with additional selection for increased 180 d weight (WT) and longissimus muscle area (LMA) and decreased backfat (BF) in the last eight generations, 2) to estimate genetic parameters for an array of traits, and 3) to investigate whether a plateau in response for BA has occurred. All lines were derived from the same Large White/Landrace composite population. Index selection for ovulation rate and embryo survival (G0-11) was initiated in L2 in 1981; L1 was selected randomly control line for L2 (G0-23). L2 …
The Evolution Of Copulation Frequency And The Mechanisms Of Reproduction In Male Anolis Lizards, Michele Johnson, Maria Lopez, Tara Whittle, Bonnie Kircher, A Dill, Divina Varghese, Juli Wade
The Evolution Of Copulation Frequency And The Mechanisms Of Reproduction In Male Anolis Lizards, Michele Johnson, Maria Lopez, Tara Whittle, Bonnie Kircher, A Dill, Divina Varghese, Juli Wade
Michele A Johnson
The evolution of many morphological structures is associated with the behavioral context of their use, particularly for structures involved in copulation. Yet, few studies have considered evolutionary relationships among the integrated suite of structures associated with male reproduction. In this study, we examined nine species of lizards in the genus Anolis to determine whether larger copulatory morphologies and higher potential for copulatory muscle performance evolved in association with higher copulation rates. In 10–12 adult males of each species, we measured the size of the hemipenes and related muscles, the seminiferous tubules in the testes, and the renal sex segments in …