Biology notes on Amphibians.

Notes Frogs, toads, salamanders, and newts ar direct descendants from fish. Amphibians evolved from a type of lobe-finned fish. The var. amphibian is from the Greek amphi, which means double, and bios, which means life. The name is endure because of the fact that they can live in water, as blow ones stack up as on land. Fossil evidence indicates that amphibians evolved from lobe-finned fishes or so 370 zillion years ago. Recent analysis of the DNA of coelacanths and lungfishes indicates lungfishes be in fact far more closely colligate to amphibians than are coelacanths. Amphibians first became common during the Carboniferous period. Biologist tag this age as the age of amphibians. By the late Carboniferous, such(prenominal) of northeast America was covered by low-lying equatorial swamplands. 34 families of amphibians thrived in this wet terrestrial environment, sharing it with pelycosaurs and other archean reptiles. In the Permian period, after the Carboniferous, amphibians increased to a hit of 40 families. During the early Permian period a remarkable veer occurred among amphibians, umpteen of them began to leave the marshes for dry uplands. Some of these amphibians had bony plates and accouterments covert their bodies, and some were as big as a pony. By the mid-Permian, 60 percent of all amphibian species were exclusively terrestrial.

During the ordinal period these remaining moist-skinned amphibians underwent a highly made assault of wet habitats all over the world. Today there are over 4,200 species of amphibians in 37 incompatible families. notwithstanding th ough each amphibian order evolved at a diffe! rent time during the Tertiary period, all modern amphibians devour certain(a) key characteristics in common. Legs, lungs, cutaneous respiration, pulmonary veins, and a partially divided heart have helped them to adapt, and is what they all have in common. There are 3,680 species of frogs and toads in 22 families. They... If you want to commove a full essay, order it on our website: BestEssayCheap.com

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