But he was rapidly proven wrong by a young Dutchman, Jan Swammerdam. Swammerdam's elegant experiments pioneered the frog nerve–muscle preparation and laid the foundation of our modern ...

But when they grow up to be frogs, their more complex bodies can no longer regenerate new members. About six years ago, Dr. Singer was making experiments on the nervous systems of newts.

Imprinted in a slab of sandstone are parts of the tadpole's skull and backbone, along with impressions of its eyes and nerves ... Researchers know frogs were hopping around as far back as ...