25 - Growth negativly impacts the life span of mammals, Rollo, D.

25 - Growth negativly impacts the life span of mammals, Rollo, D.

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Article 22 Summary: Growth Negatively Impacts the Life Span of Mammals Background Info In 1933, McCay proposed that growth and longevity varied inversely within mammalian species o Tested by stunting the growth of rats by limiting their food intake and found that their were substantial increases in longevity Today, this “dietary restriction paradigm” involves reducing calories consumed Findings that body size and longevity interspecifically positively relate, and preliminary findings that growth hormone may offset human senescence oppose McCay’s hypothesis Methods Data came from journal articles across the 20 th century Variation was wide ranging and included group sizes, photoperiod, humidity, maternal influence among others… hence only a strong factor could emerge from such variable background data Results Maximal longevity showed highly significant declines with increasing mature mass in both rats and mice
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25 - Growth negativly impacts the life span of mammals, Rollo, D.

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