The evolution of life has not been an orderly affair. Every time a biological age is swept aside, a few creatures remain. Millions of years later, many are still with us.

Sometimes these animals are called "living fossils," but it's not a good term. After all, their lineages haven't survived ice ages and warm spells and every natural upheaval just to be visualized in amber by some upstart hairless ape. A better term is "evolutionarily distinct." They're simply, impressively unique.

"Evolutionarily distinct creatures contain more genetic diversity. They look different. They tend to be...

2005: The design for Freedom Tower, meant to replace the World Trade Center towers destroyed in the Sept. 11 attacks, is formally introduced.

The tower will rise 1,776 feet above Lower Manhattan, replacing 2.6 million of the 15 million square feet of office space lost when the twin towers and a nearby building collapsed. Three other new towers will accompany it in the rebuilt WTC.

But Freedom Tower, designed by architects Daniel Libeskind and David Childs, is about much more than creating new office space. Its design is symbolic (as well as tremendously reinforced). The...