An oft-conjured image when imagining the process of evolution is of fish crawling out of water on four limbs. A common theory explains this fish-moving-to-land event as a result of shrinking lakes and ponds in a desert environment. Professor Gregory J. Retallack of the University of Oregon’s department of geological sciences, however, posits that this is an unlikely hypothesis. Examining fossils from the Devonian (approximately 416 to 359 million years ago) and Carboniferous (359 to 299 million years ago) geological ages, Professor Retallack found that the fossils were associated not with arid desert conditions, but rather, humid woodland soils. He hypothesizes that our distant ancestors were not trying to escape but rather to take advantage of the richly nutritive environment that vegetative woodland banks have to offer. Limbs would allow the creatures to navigate roots and logs; another adaptation found in this period are flexible necks that allowed for feeding in shallow waters.