The sudden appearance of fossils that marks the so-called 'Cambrian explosion' has intrigued and exercised biologists since Darwin's time. In On the Origin of Species, Darwin made it clear that he believed that ancestral forms 'lived long before' their first fossil representatives. While he considered such an invisible record necessary to explain the level of complexity already seen in the foss...

This paper looks more closely at the sources of patent growth in the United States since 1984. It confirms that the increase is largely due to US patenters, with an earlier surge in Asia, and some increase in Europe. Growth has taken place in all technologies, but not in all industries, being concentrated in the electrical, electronics, computing, and scientific instruments industries. It then ...