User:Bs4234/sandbox

Practicing Citations
Compared to other early whales, like Indohyus and Pakicetus, Ambulocetus looks like it lived a more aquatic lifestyle. Its legs are shorter, and its hands and feet are enlarged like paddles.

Interestingly, in 1859 Charles Darwin related a scene of a swimming bear catching insects in the water to that of a whale catching its food and even alluded to the possibility of a bear-like creature being rendered by natural selection to become increasingly marine, eventually giving rise to something such as a whale.

Even though the sister-group to Cetacea is not resolved in the strict consensus for trees supported by the intrinsic data set, all optimal trees for our analyses with and without stratigraphy support a close phylogenetic relationship between Hippopotamidae and Cetacea.

Modern cetaceans show numerous phenotypic adaptations for life in the water; aside from the radical reorganization of their forelimbs into fins and loss of hindlimbs, they are able to dive and tolerate low oxygen, and possess modified circulatory and respiratory systems, large brains, hairlessness and transformations in sensory perception.

Based on morphological traits, hippos have traditionally been classified with pigs and peccaries in the suborder Suiformes. However, molecular data indicate that hippos and cetaceans are sister taxa.

Evolution (practice paragraph)
Phylogenetic evidence suggests that the last common ancestor of cetaceans and hippopotamuses lived between 40 and 60 Mya. Over time, this ancestor diverged into two distinct groups: the early ancestors of modern cetaceans and hippopotamuses respectively. Anatomically modern hippopotamuses probably appeared around 20 Mya, part of a larger group of amphibious mammals, the anthracotheres. The link between cetaceans and hippopotamuses was allegedly difficult for palaeontologists to establish, especially given that morphological evidence and dentition both seemed to indicate that hippopotamuses were most closely related to peccaries and pigs in Suidae. The classification of cetaceans has also been contentious, with modern understanding still uncertain of their place in Artiodactyla.

Answers to Module 7 Questions

 * The media is a photograph of Narrabeen Lake from Wheeler Heights, taken on a morning run.
 * The photograph is my original work.
 * It is a .jpg file.
 * I would use Public Domain License.
 * I would add it to the Landscape category.
 * See the first bullet point.