Evolution of whale body size

Atocetus, an early fossil odontocete (“toothed whale”). Since this specimen has both total length and a well preserved skull, we can use it as a validation case for our reconstructions.

How big were ancient whales? Body size is perhaps the most obvious functionally important feature of an organism, yet it is complexly determined by many genes and environmental factors. Understanding body size trends through time and correlations with evolutionary transitions and ecology can give insight into characteristics of the process of evolution itself. Body size […]

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Gecko adhesive hairs gets stickier the faster they slide

The branching hair structure of gecko adhesive hairs and an synthetic gecko adhesive that captures the same unusual friction and adhesive properties as the gecko system.

Frictional (a) and adhesive forces (b) of a gecko’s adhesive foot pads increase with increasing sliding velocity. Negative force in (b) indicates sticking to the surface. Figure from Gravish, et al. 2010, Interface. Even geckos encounter perturbations and environments that can challenge their ability to stick. The hairs of a gecko’s foot are composed of […]

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How do geckos stick to almost any surface?

Myriad gecko feet. Photo credit:  Paul Stewart, Cover image for Autumn, et al. 2002 PNAS

It turns out that gecko feet are covered in millions of tiny hairs called setae. Each of these hairs branches into 100-1000 spatulae each of which is narrower than the wavelength of visible light (< 300 nm)! Before this project,  research had shown that intermolecular forces binding the gecko’s setae to the surface are responsible for […]

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