Speaking of stick-to-it-ivity:

"Adam Engler, a bioengineering assistant professor from UC San Diego's Jacobs School of Engineering, is the first author of the Review article entitled "Multiscale Modeling of Form and Function" published in the April 10 issue of the journal Science. According to Engler, there is something inherent in the nature of the ever-present tasks of sticking together and responding to forces that causes common form and function to emerge. For example, even though the cells within bacteria, fungi, sponges, nematodes and humans do not use exactly the same proteins to stick together, all of these organisms rely on fundamental components of cell-cell adhesions for survival. For this reason, the capacity to form complex multilayer organisms through cell-cell interactions is likely based on the evolutionary advantage to adhere to new environments and survive in potentially hostile environments, the authors say.
The team also described a universal need for cells, tissues, organs and organisms to respond to forces. Two examples of very different biological structures that nevertheless rely on responsiveness to forces for proper function are leg bones and breast acini. Breast acini are hollow spherical objects at the ends of breast ducts that are made of a layer of cells that secrete milk proteins. Breast acini form hollow spheres, according to Engler, because this form maximizes the surface to volume ratio. When pressure builds up, acini can hold more and more volume until they need to push the milk proteins down the duct.
"This kind of structure is conserved in a variety of dissimilar systems that respond to forces in a manner similar," said Engler. The long bones of the human skeleton are another example, where their elongated and cylindrical form optimizes the distribution of body weight while remaining very light.
Thinking Wide
Engler hopes that the observations and connections he and his coauthors make regarding the ubiquitous need for vastly different cells, tissues, organs and organisms to use common biological modules will encourage other scientists and engineers to think beyond their specific areas of specialization."

(PhysOrg.com:)