Aquatic adaptation
- Aquatic adaptation
Several
animal groups have undergone aquatic adaptation, going from being purely terrestrial animals to living at least part of the time in water. The adaptations in early speciation tend to develop as the animal ventures into water in order to find available food. As successive generations spend more time in the water, natural selection causes the acquisition of more adaptations. Animals of later generations may spend the majority of their life in the water, coming ashore for mating. Finally, fully adapted animals may take to mating and birthing in water.Anapsid s"
Archelon ", was a genus giantCretaceous sea turtle ."
Mesosaurus " (and other mesosaurids) were one of the firstreptiles to secondarily return to the sea.Cetacea nsDuring the
Paleocene Epoch (about 55-65 million years ago), a group ofwolf -likeartiodactyl s related to "Pakicetus " began pursuing an amphibious lifestyle in rivers or shallow seas. They were the ancestors of modern whales.Diapsid sLiving at the same time as, but not closely related to, dinosaurs, the
mosasaur s andpliosaur s resembled crocodiles but were more strongly adapted to marine life. They became extinct within a few million years of the dinosaurs. Modern diapsids which have adapted to marine life include marineiguana s and marinecrocodile s.Euryapsid sThese marine reptiles had ancestors who moved back into the oceans, In the case of
ichthyosaur s adapting as fully as thedolphins they superficially resemble, even giving birth to live offspring instead of laying eggs, in other cases more to the extent of the seal, as withplesiosaur s andplacodont s.Human sSome people believe that part of
human evolution includes some aquatic adaptation, which has been said to explain human hairlessness, webbed digits, bipedal locomotion, and various other physiological changes. In addition, there have been numerous inventions of devices by humans to adapt to the aquatic environments.Pinniped sThe fossil records show that
phocid s existed 12 to 15 million years ago, andodobenid s about 14 million years ago. Their common ancestor must have existed even earlier than that.Polar Bear sAlthough still primarily a terrestrial animal, the polar bear shows the beginnings of aquatic adaptation to swimming (body fat, closable nostrils), diving, and thermoregulation. Distinctly polar bear fossils can be dated to about 100,000 years ago.
Sirenia nsThe ancestors of the
dugong andmanatee s first appeared in the fossil record about 45 to 50 million years ago in the Eocene.
Wikimedia Foundation. 2010.
Look at other dictionaries:
Aquatic plant — Aquatic plants mdash; also called hydrophytic plants or hydrophytes mdash; are plants that have adapted to living in or on aquatic environments. Because living on or under water surface requires numerous special adaptations, aquatic plants can… … Wikipedia
Aquatic Genet — Aquatic Genet[1] Conservation status Data Deficient (IUCN 3.1)[2 … Wikipedia
Aquatic-Ape-Hypothese — Unter dem Begriff Wasseraffen Theorie (Bezeichnungen wie Wassertheorie, Wasseraffen Hypothese oder Aquatic Ape Hypothese wurden auch verwendet) ist eine Reihe von Spekulationen bekannt geworden, nach der die Vorfahren der Menschen in ihrer… … Deutsch Wikipedia
Aquatic-Ape-Theorie — Unter dem Begriff Wasseraffen Theorie (Bezeichnungen wie Wassertheorie, Wasseraffen Hypothese oder Aquatic Ape Hypothese wurden auch verwendet) ist eine Reihe von Spekulationen bekannt geworden, nach der die Vorfahren der Menschen in ihrer… … Deutsch Wikipedia
Aquatic ape hypothesis — The aquatic ape hypothesis (AAH), sometimes referred to as the aquatic ape theory, asserts that wading, swimming and diving for food exerted a strong evolutionary effect on the ancestors of the genus Homo and is in part responsible for the split… … Wikipedia
A.A.T. (Aquatic Ape Theory) — Théorie du primate aquatique La Théorie du Primate Aquatique (de l anglais A.A.T. ou Aquatic Ape Theory) est une hypothèse qui propose un ancêtre aquatique ou semi aquatique parmi ceux de l homme moderne ce qui aurait notamment contribué à l… … Wikipédia en Français
Life Sciences — ▪ 2009 Introduction Zoology In 2008 several zoological studies provided new insights into how species life history traits (such as the timing of reproduction or the length of life of adult individuals) are derived in part as responses to… … Universalium
respiration — respirational, adj. /res peuh ray sheuhn/, n. 1. the act of respiring; inhalation and exhalation of air; breathing. 2. Biol. a. the sum total of the physical and chemical processes in an organism by which oxygen is conveyed to tissues and cells,… … Universalium
Pelagic fish — A school of large pelagic predator fish (giant trevally) sizing up a school of small pelagic prey fish (anchovies) Pelagic fish live near the surface or in the water column of coastal, ocean and lake waters, but not on the bottom of the sea or… … Wikipedia
angiosperm — /an jee euh sperrm /, n. Bot. a plant having its seeds enclosed in an ovary; a flowering plant. Cf. gymnosperm. [ANGIO + SPERM] * * * ▪ plant Introduction any member of the more than 300,000 species of flowering plants (division Anthophyta) … Universalium
