Evolution of Dolphins: Difference between revisions
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[[Image: AncestorsofDolphins.jpg|thumb|300px|right|Dolphins evolved from terrestrial animals into aquatic animals throughout generations of evolution. The dolphins share numerous ancestors with the bowhead whale. https://sites.google.com/site/obenscience7e/unit-1-why-do-organisms-look-like-that/a-case-study-how-modern-whales-came-to-be.]] | [[Image: AncestorsofDolphins.jpg|thumb|300px|right|Dolphins evolved from terrestrial animals into aquatic animals throughout generations of evolution. The dolphins share numerous ancestors with the bowhead whale. https://sites.google.com/site/obenscience7e/unit-1-why-do-organisms-look-like-that/a-case-study-how-modern-whales-came-to-be.]] | ||
The evolution of dolphins, or <i>Delphinus</i>, is believed to have started with the <i>Pakiectus</i> a four legged, land walking mammal. The <i>Pakiectus</i> dates back to approximately 50 million years ago. Throughout the centuries, these animals have gone through drastic changes to become the modern day dolphin. Along with the <i>Pakiectus</i>, the dolphin is thought to have evolved alongside or from the <i>Ambulocetus</i>, <i>Protocetid</i>, <i>Dorudontid</i>, <i>Squalodontidae</i>, <i>Aetiocetidae</i>, and <i>Kentriodontidae</i> to eventually become the <i>Delphinus</i>.<ref>[https://dolphin-academy.com/learn/evolution]</ref> The Pakiectus lived near the shallow waters and began to feed on organisms that lived in these waters, which began the transition from terrestrial to aquatic animals. The bone structure of the flipper in the modern dolphin is very similar to the structure found in the Pakiectus legs and hooves, confirming the link between the two organisms.<ref>[https://www.dolphins-world.com/dolphin-evolution/]</ref> | The evolution of dolphins, or <i>Delphinus</i>, is believed to have started with the <i>Pakiectus</i> a four legged, land walking mammal. The <i>Pakiectus</i> dates back to approximately 50 million years ago. Throughout the centuries, these animals have gone through drastic changes to become the modern day dolphin. Along with the <i>Pakiectus</i>, the dolphin is thought to have evolved alongside or from the <i>Ambulocetus</i>, <i>Protocetid</i>, <i>Dorudontid</i>, <i>Squalodontidae</i>, <i>Aetiocetidae</i>, and <i>Kentriodontidae</i> to eventually become the <i>Delphinus</i> which is found in the <i>Cetacea</i> infraorder.<ref>[https://dolphin-academy.com/learn/evolution]</ref> The <i>Pakiectus</i> lived near the shallow waters and began to feed on organisms that lived in these waters, which began the transition from terrestrial to aquatic animals. The bone structure of the flipper in the modern dolphin is very similar to the structure found in the Pakiectus legs and hooves, confirming the link between the two organisms.<ref>[https://www.dolphins-world.com/dolphin-evolution/]</ref> | ||
Over the 50 million years of evolution, the ancestors of dolphins adapted from being terrestrial to aquatic. A characteristic that is mainly found in terrestrial animals is that of a vertical spine. Dolphins have vertical spines leaving them swimming with vertical movements, while fish movements are horizontal.<ref>[https://www.dolphins-world.com/dolphin-evolution/]</ref> In comparison to the <i>Pakiectus</i>, dolphins hav much larger skulls with a shape that has adapted to accommodate for a padded lower jaw and extended middle ear. Having an extended middle ear allows the dolphins to use echolocation for communication. As the ancestors of dolphins moved toward living aquatically, the nostrils evolved into a blowhole to expend less energy while surfacing to breathe. The ancestors of dolphins that lived terrestrially had legs to walk. Dolphins have two small pelvic bones that are rod shaped that are now vestigial legs from their land walking ancestors.<ref>[https://www.dolphins-world.com/dolphin-evolution/]</ref> | Over the 50 million years of evolution, the ancestors of dolphins adapted from being terrestrial to aquatic. A characteristic that is mainly found in terrestrial animals is that of a vertical spine. Dolphins have vertical spines leaving them swimming with vertical movements, while fish movements are horizontal.<ref>[https://www.dolphins-world.com/dolphin-evolution/]</ref> In comparison to the <i>Pakiectus</i>, dolphins hav much larger skulls with a shape that has adapted to accommodate for a padded lower jaw and extended middle ear. Having an extended middle ear allows the dolphins to use echolocation for communication. As the ancestors of dolphins moved toward living aquatically, the nostrils evolved into a blowhole to expend less energy while surfacing to breathe. The ancestors of dolphins that lived terrestrially had legs to walk. Dolphins have two small pelvic bones that are rod shaped that are now vestigial legs from their land walking ancestors.<ref>[https://www.dolphins-world.com/dolphin-evolution/]</ref> | ||
Revision as of 21:56, 2 December 2019
Introduction
The evolution of dolphins, or Delphinus, is believed to have started with the Pakiectus a four legged, land walking mammal. The Pakiectus dates back to approximately 50 million years ago. Throughout the centuries, these animals have gone through drastic changes to become the modern day dolphin. Along with the Pakiectus, the dolphin is thought to have evolved alongside or from the Ambulocetus, Protocetid, Dorudontid, Squalodontidae, Aetiocetidae, and Kentriodontidae to eventually become the Delphinus which is found in the Cetacea infraorder.[1] The Pakiectus lived near the shallow waters and began to feed on organisms that lived in these waters, which began the transition from terrestrial to aquatic animals. The bone structure of the flipper in the modern dolphin is very similar to the structure found in the Pakiectus legs and hooves, confirming the link between the two organisms.[2]
Over the 50 million years of evolution, the ancestors of dolphins adapted from being terrestrial to aquatic. A characteristic that is mainly found in terrestrial animals is that of a vertical spine. Dolphins have vertical spines leaving them swimming with vertical movements, while fish movements are horizontal.[3] In comparison to the Pakiectus, dolphins hav much larger skulls with a shape that has adapted to accommodate for a padded lower jaw and extended middle ear. Having an extended middle ear allows the dolphins to use echolocation for communication. As the ancestors of dolphins moved toward living aquatically, the nostrils evolved into a blowhole to expend less energy while surfacing to breathe. The ancestors of dolphins that lived terrestrially had legs to walk. Dolphins have two small pelvic bones that are rod shaped that are now vestigial legs from their land walking ancestors.[4]
Section 1 Genetics
Include some current research, with at least one image.
Sample citations: [5]
[6]
A citation code consists of a hyperlinked reference within "ref" begin and end codes.
Section 2 Microbiome
Include some current research, with a second image.
Conclusion
Overall text length should be at least 1,000 words (before counting references), with at least 2 images. Include at least 5 references under Reference section.
References
Edited by [Carolyn Herbosa], student of Joan Slonczewski for BIOL 116 Information in Living Systems, 2019, Kenyon College.
