Because of the difference in their size and weight, the weaker animal would have to struggle to keep up the pace, and the stronger would have a greater burden to bear.
ولكن بسبب الفرق في الحجم والوزن ،‏ يناضل الحيوان الاضعف للحفاظ على سرعة تقدمه بينما يتحمل الحيوان الاقوى العبء الاكبر .‏