There are many similarities between hiccuping and gill ventilation in animals like tadpoles, the researchers argue. Both are inhibited when the lungs are inflated, for example, and by high carbon dioxide levels in air or water. But why do we still hiccup 370 million years after our ancestors began hauling themselves onto land?
If the team is right, hiccupping before birth is just an early stage in the development of suckling, a little like learning to crawl before you can walk. Straus thinks the circuitry that controls the movements of the gills and glottis was conserved during evolution because it formed a building block for more complex motor patterns, such as suckling in mammals. “Hiccups may be the price to pay to keep this useful pattern generator,” he says.
The US National Institute of Standards and Technology will soon be testing a controversial theory about the collapse of the World Trade Center towers.
According to an analysis by a leading fire-safety expert, had the fire-proofing insulation on the towers’ steel structures been thicker, the towers would have survived longer and might even have remained standing after they were hit by the hijacked planes. The work is being seized on by lawyers representing victims’ families and insurance companies.
If confirmed, it could also lead to changes in building codes.