| Evolutionary History/Biogeographic History |
| Although there is no direct and certain knowledge about the origin of penguins, some major theories have developed since Magellan first called them "strange geese" (Muller-Schwartz back cover). There have so far been no fossilized remains of an ancient penguin-ancestor (ie) a transitional animal from a previous species (missing link) found; however, scientists speculate that the transition from aerial birds to non-flying penguins occurred in the Cretaceous period, roughly 65 million years ago, with various specialization and differentiation occurring throughout the Paleocene (Simpson 58). But no fossils have so far been found at the depths of these periods. The oldest penguin fossils date to 45 million years ago, and by that time they were already specialized to the present day recognizable "penguin" and in many senses were "even more specialized, that is, less primitive than those [penguins] still extant" (Simpson 58). Those earliest penguins were found in South Australia (possible ancestors of Eudyptula minor), New Zealand, South Island and Antarctica, and many believe that speciation and evolution were "essentially over by the end of the Eocene" (Simpson 60). However, evidence of extinction is present. At least nine more genera of penguin existed at the beginning of the Miocene that do not exist today. In New Zealand "there are at least four genera and five species...[although] there is now only one species (little blues)" (Simpson 62). Extinction of most of the genera were true extinctions where they have no connection of evolution to current penguins. Therefore, it would seem, that current penguins are the direct decendants of non-extinct "ancient" penguins. The reason for extinction is unknown but one hypothesis is based on size. "In the Miocene...there were a number of unusually large penguins" (Simpson 64). It is then reasonable to believe that intra-species competition between major predators, of which these penguins were, and the increase in seals and dolphins that may have eaten these penguins, lead to their eventual extinction. The closest in skeletal structure to Eudyptula minor is Archaeospheniscus wimani, which stood about 1'7'' and lived in New Zealand. This is compared to the Blue Penguin's 1'2'' whom inhabits the same land (Simpson 67). However no "missing link" or transitional skeleton can be found, although some point to the Auk, a bird adapted to flight but also deep water diving with a penguin-like structure, to be an example of co-evolution from a common flying-bird ancestor of present day penguins (Simpson 74). |