Philip D. Gingerich a paleontoliogist most know for his study on the ancestry of whales.
Starting in the late 1970's Gingerich has gathered fossil speciments of early whales. Some of his "dig" sites were in Egypt and Pakistan. When he was working with Pakistani collegues Pakicetus was found. Pakicetus is a terrestial mammal which is about 50 million years old. The 50 million year mammal's earbones look similar to other whales but the skull looks similar to a dog's skull.
Hans Thewissen, a former student of Gingerich found a creature and called it Ambulocetus Natans (Walking and Swimming Whale). Ambulocetus Natans is a slightly more recent creature, who has "webbed feet, legs suitable for either walking or swimming and has a long toothy snout" (National Geographic, Nov. 2004, Page 30-31).
After finding several more sea and land creatures Gingerich found Rodhoctus Balochistanensis. The Rodhoctus Balochistanensis "was fully a sea creature, its legs more like flippers, its nostrils shifted backward on the snout, halfway to the blowhole position on a modern whale" (National Geographis, Nov. 2004, Page 30-31).
Gingerich believes that whales are descendents of "a group of carnivorous Eocene mammals known as Mesonychids" which have cheek teeth used for chewing bone and meat (National Geographic, Nov. 2004, Page 30-31).
The ankle bones of the skeletons found during the field work in Pakistan in 2000 established their origin from Artiodactyla (cows, deer, hippos) and that whales did not originate from Maesonychid Condylarths as was expected. http://www-personal.umich.edu/~gingeric/PDGwhales/Whales.htmhttp://www-personal.umich.edu/~gingeric/PDGwhales/Whales.htm
However, other scientists that had also been studying the evolution of whales came up with a different ancestor than meat-eating mesonychids. "DNA hybridization and other tests suggested that whales had descended from artiodactyls (that is, even toed herbivores, such as antelopes and hippos), not from meat-eating mesonychids." (National Geographis, Nov. 2004, Page 30-31).
Gingerich named the new species of whale Artiocetus clavis. "It felt solid and heavy as truth" (National Geographis, Nov. 2004, Page 30-31).
"It took less than 15 million years for the whale lineage to move from land, through shallow bays and coastal waters, to deep marine environments. By 40 million years ago whales had become essentially the animals we know today." (http://members.aol.com/darwinpage/landtosea.htm.
The fossils of the whale species is solid proof of evolution. It has even caused some creationalist to believe in it such as Philip Gingerich who "grew up in a conservative church in the Midwest and was not taught about evolution."
