But a six-letter alphabet could encode as many as 216 possible amino acids and many, many more possible proteins. Olena Shmahalo/Quanta Magazine Why nature stuck with four letters is one of ...

For the first time, scientists have expanded life's genetic alphabet, by inserting two unnatural, man-made "letters" into a bacterium's DNA, and by showing that the cell's machinery can copy them. The ...

DNA's instructions are written in a code of four molecular "letters," labeled A, C, T and G. For the first time, researchers have created and inserted two brand-new letters into a living cell.

Nature photographer Kjell Bloch Sandved has amassed a massive collection of butterfly and moth wings, capturing a host of unusual patterns. Using those patterns, he has assembled entire butterfly ...

Discovering Nature's Alphabet Krystina Castella, Brian Boyl, . . Heyday, $15.95 (0pp) ISBN 978-1-59714-021-8 ...