[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

NOVA Special Airing Tonight Featuring Ted Daeschler From Philly's Academy of Natural Sciences

Please watch!
 (I apologize for the cross-posting)
Philadelphia - The scientific details of how and why a particular group of fish evolved limbs 370 million years ago, eventually leading to all four-legged animals, has intrigued scientists for more than a century. Recent discoveries, including several by researchers from The Academy of Natural Sciences, are part of the paleontological detective story that will come to light on Tuesday, February 26, when NOVA premiers "The Missing Link" on WGBH, Channel 12 in the Philadelphia area.

The Academy's paleontologist Dr. Ted Daeschler of Wyndmoor, Pa., is among the scientists interviewed on the show. Since 1993 Daeschler's discoveries of Devonian-age fossils (410-360 million years old) in Pennsylvania have helped revise the prevalent theories regarding how and why four-limbed creatures like us developed limbs. His discoveries have opened up new ways of thinking about the forces that drove the evolution from fish to the first limbed animals.

"It's a detective story, and you're finding evidence out there," Daeschler tells viewers on "The Missing Link." "We're looking for little pieces of evidence to help piece together this story of how limbs develop from fins."

Daeschler and others from the Academy have spent thousands of hours searching for fossils along road cut exposures of Devonian-age sandstone called the Catskill Formation in north-central Pennsylvania. They have uncovered many notable finds including the oldest tetrapod fossils (animal with four limbs) ever found in North America. "We are finding fish with limb-like fins and limbed animals with fish-like features. We're on the cusp of a major evolutionary transition," said Daeschler. The fossils from this work are permanently housed in The Academy of Natural Sciences' Department of Vertebrate Paleontology, alongside more than 22,000 other fossils in the venerable research collection. "We've made Philadelphia a center for the study of these kinds of fossils, and appearing on Nova helps validate our research program."

The discovery of abundant plant fossils in the rock with the earliest tetrapods has also changed the theory that the land at the time was dry and barren. Instead, these findings suggest that by the end of the Devonian Period Earth was etched with rivers which were bordered by something completely new: swamps and forests, providing an important ecological opportunity for our ancient kin.

"The Missing Link" traces the incredible 400-million-year-old detective story of how and why creatures first left the water to live on land.
Patti Kane-Vanni
pkv1@erols.com  or  pkvanni@sas.upenn.edu