Changes

The term whale refers to all [[Cetacean|Cetaceans]] that are not [[dolphin|dolphins]] or [[Poprpoise|porpoises]] or more informally to only the very largest [[Cetacean|Cetaceans]]. Although whales are famed for the massive size reached by some species, like the largest animal to ever live the [[Blue Whale]], others are relatively small like the pygmy right whale which grows to about 20 feet <ref> American Cetacean Society website [http://www.acsonline.org/factpack/PygmyRightWhale.htm]</ref>.  Though whales have  many traits in common with fish (including fins and tails) they are in fact [[mammal|mammals]] and accordingly breath air and lactate. Whales have a number of remarkable [[adaptation|adaptations]] including:

The term whale refers to all [[Cetacean|Cetaceans]] that are not [[dolphin|dolphins]] or [[Poprpoise|porpoises]] or more informally to only the very largest [[Cetacean|Cetaceans]]. Although whales are famed for the massive size reached by some species, like the largest animal to ever live the [[Blue Whale]], others are relatively small like the pygmy right whale which grows to about 20 feet <ref> [http://www.acsonline.org/factpack/PygmyRightWhale.htm]American Cetacean Society website</ref>.  Though whales have  many traits in common with fish (including fins and tails) they are in fact [[mammal|mammals]] and accordingly breath air and lactate. Whales have a number of remarkable [[adaptation|adaptations]] including:

* they decide when to breathe, rather than breathing unconsciously

* they decide when to breathe, rather than breathing unconsciously

== Evolution and taxonomy ==

== Evolution and taxonomy ==

The question of how whales and their relatives could have evolved from terrestial [[mammall|mamalls]] has taxed evolutionary biologists since [[Darwin|Darwin's]] suggestion that may have evolved from ancient bears. In more recent times molecular and fossil evidence has combined to suggest that modern whales and their relatives arose from ancient [[Artiodactyla|artiodactyls]] (even-toed ungulates) with the cloest living relative of all whales  being hippos<ref> Theodore, JM (2004) Molecular Clock Divergence Estimates And The Fossil Record Of Cetartiodactyla <i> The Journal Of Paleontology 78:39-44[http://www.redorbit.com/news/science/41080/molecular_clock_divergence_estimates_and_the_fossil_record_of_cetartiodactyla/index.html]</ref>. This kinship has been termed the whippo hypothesis. Evolutionary biologists estimate the last American Cetacean Society ancestor of whales and hippos lived about 25 million years ago <ref> UCLA berkley "Understanding Evolution for Teachers" website [http://evolution.berkeley.edu/evosite/lines/IAtransitional.shtml]</ref>, which is contrast with the [[Young earth creationism|young earth creationist]] position that that whales were [[creation|created]] about 4000 years ago when [[God]] created the [[earth]].

The question of how whales and their relatives could have evolved from terrestial [[mammall|mamalls]] has taxed evolutionary biologists since [[Darwin|Darwin's]] suggestion that they may have evolved from ancient bears. In more recent times molecular and fossil evidence has combined to suggest that modern whales and their relatives arose from ancient [[Artiodactyla|artiodactyls]] (even-toed ungulates) with the closest living relative of all whales  being hippos<ref>[http://www.redorbit.com/news/science/41080/molecular_clock_divergence_estimates_and_the_fossil_record_of_cetartiodactyla/index.html] Theodore, JM (2004) Molecular Clock Divergence Estimates And The Fossil Record Of Cetartiodactyla <i> The Journal Of Paleontology</i> <b>78</b>:39-44</ref>. This kinship has been termed the whippo hypothesis. Evolutionary biologists estimate the last American Cetacean Society ancestor of whales and hippos lived about 25 million years ago <ref> [http://evolution.berkeley.edu/evosite/lines/IAtransitional.shtml] UCLA Berkley Understanding Evolution for Teachers website</ref>, which is contrast with the [[Young earth creationism|young earth creationist]] position that that whales were [[creation|created]] about 4000 years ago when [[God]] created the [[earth]].