Size and gravity
An organism’s structure, form and function are shaped by the process of evolution through natural selection. However, evolution is constrained by the universal forces of physics, like gravity.
Professor Brian Cox explains why gravity limits the size of plants and animals. Using blocks of wood, he demonstrates how a doubling of linear size results in an eight-fold increase in mass. He describes the limitations this relationship has on animals including the kangaroo and rhinoceros beetle.
Available since: Wed 13 Mar 2013
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- Evolution of hearing Duration: 05:18 Learning Zone, Episode 2