摘要 : <![CDATA[<ce:abstract xmlns:ce="http://www.elsevier.com/xml/common/dtd" xmlns="http://www.elsevier.com/xml/ja/dtd" id="abs0005" view="all" class="author"> <ce:abstract-sec id="abst0005" view="all"> <ce:simple-para id="spar0045" vi... 展开 <![CDATA[<ce:abstract xmlns:ce="http://www.elsevier.com/xml/common/dtd" xmlns="http://www.elsevier.com/xml/ja/dtd" id="abs0005" view="all" class="author"> <ce:abstract-sec id="abst0005" view="all"> <ce:simple-para id="spar0045" view="all">Hypometric scaling of aerobic metabolism in animals has been widely attributed to constraints on oxygen (O<ce:inf loc="post">2</ce:inf>) supply in larger animals, but recent findings demonstrate that O<ce:inf loc="post">2</ce:inf> supply balances with need regardless of size. Larger animals also do not exhibit evidence of compensation for O<ce:inf loc="post">2</ce:inf> supply limitation. Because declining metabolic rates (MRs) are tightly linked to fitness, this provides significant evidence against the hypothesis that constraints on supply drive hypometric scaling. As an alternative, ATP demand might decline in larger animals because of performance–safety tradeoffs. Larger animals, which typically reproduce later, exhibit risk-reducing strategies that lower MR. Conversely, smaller animals are more strongly selected for growth and costly neurolocomotory performance, elevating metabolism.</ce:simple-para> </ce:abstract-sec> </ce:abstract><ce:abstract xmlns:ce="http://www.elsevier.com/xml/common/dtd" xmlns="http://www.elsevier.com/xml/ja/dtd" id="abs0010" class="sda" view="all"> <ce:section-title id="sect0005">Trends</ce:section-title> <ce:abstract-sec id="abst0010" view="all"> <ce:simple-para id="spar0050" view="all">Animal size does not affect limiting O<ce:inf loc="post">2</ce:inf> levels, based on physiological tests.</ce:simple-para> <ce:simple-para id="spar0055" view="all">Larger animals show no evidence of attempting to compensate for O<ce:inf loc="post">2</ce:inf> supply limits.</ce:simple-para> <ce:simple-para id="spar0060" view="all">Smaller animals have more expensive neuromuscular and anabolic systems.</ce:simple-para> <ce:simple-para id="spar0065" view="all">Larger animals have characteristics that reduce risk and energy use.</ce:simple-para> <ce:simple-para id="spar0070" view="all">Declining mass-specific ATP demand might cause hypometric scaling of MR.</ce:simple-para> </ce:abstract-sec> </ce:abstract>]]> 收起