Research Paper Volume 8, Issue 12 pp 3209—3222

Birth mass is the key to understanding the negative correlation between lifespan and body size in dogs

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Figure 3. Birth mass is not proportional to adult mass in dogs. (A) and (B): Birth mass scales with adult mass sub-linearly in male and female dogs, respectively. (C) and (D): Birth/adult mass ratio negatively scale with adult mass in male and female dogs, respectively. Each point represents one breed. In each gender, the sum of the absolute values of the scaling powers of the birth mass and the ratio, in principle, should be equal to 1. They are close, but not exactly equal to 1, because dividing the birth mass by the adult mass M in the ratio, µ = m0/M, introduces noise from M. Nonetheless, as Figure 3 shows, the noise is negligible, as the sums of the powers are 0.48+0.55 = 1.03 in males and 0.45+0.51 = 0.96 in female dogs.