Frog2

Litoria chloris, also commonly known as the red-eyed tree frog or orange-eyed tree frog, is a species of tree frog native to eastern Australia; ranging from north of Sydney to Proserpine in mid-northern Queensland.

A tree frog is any frog that spends a major portion of its lifespan in trees, known as an arboreal state. Several lineages of frogs among the Neobatrachia have given rise to tree frogs, even though they are not closely related to each other.

Many millions of years of convergent evolution have resulted in almost identical morphology and ecologies. In fact, they are so similar as regards their ecological niche that in one biome where one group of tree frogs occurs, the other is almost always absent. The last common ancestor of some such tree frog groups lived long before the extinction of the dinosaurs.^{[citation needed]}

Animal coloration is the general appearance of an animal resulting from the reflection or emission of light from its surfaces. Some animals are brightly coloured, while others are hard to see. In some species, such as the peacock, the male has strong patterns, conspicuous colours and is iridescent, while the female is far less visible.

There are several separate reasons why animals have evolved colours. Camouflage enables an animal to remain hidden from view. Signalling enables an animal to communicate information such as warning of its ability to defend itself (aposematism). Animals also use colour in advertising, signalling services such as cleaning to animals of other species; to signal sexual status to other members of the same species; and in mimicry, taking advantage of another species' warning coloration. Some animals use colour to divert attacks by startle (deimatic behaviour), surprising a predator e.g. with eyespots or other flashes of colour, and possibly by motion dazzle, confusing a predator's attack by moving a bold pattern (such as zebra stripes) rapidly. Some animals are coloured for physical protection, such as having pigments in the skin to protect against sunburn, while some frogs can lighten or darken their skin for temperature regulation. Finally, animals can be coloured incidentally. For example, blood is red because the haem pigment needed to carry oxygen is red. Animals coloured in these ways can have striking natural patterns.

The Lissamphibia are a subclass of animals that includes all recent amphibians. The name derives from the Greek for 'smooth amphibia'. For several decades, this name has been used for a group that includes all extant amphibians, but excludes all the main groups of Paleozoic tetrapods, such as Temnospondyli, Lepospondyli, Embolomeri, and Seymouriamorpha. Some authors hold that Lissamphibia is a clade, that the subclass consists of all the descendants of an ancestral lissamphibian, but others hold that frogs and salamanders derive from temnospondyls, whereas caecilians derive from lepospondyls, so Lissamphibia is polyphyletic.

Living amphibians fall into one of three orders: the Anura (frogs and toads), the Caudata or Urodela (salamanders and newts), and the Gymnophiona or Apoda (the limbless caecilians). An extinct group, the family Albanerpetontidae in the order Allocaudata, was moderately successful, spanning 160 million years from the Middle Jurassic to the Early Pliocene, an interval that ended 3.6 million years ago.

Arboreal locomotion is the locomotion of animals in trees. In every habitat in which trees are present, animals have evolved to move in them. Some animals may only scale trees occasionally, while others are exclusively arboreal. These habitats pose numerous mechanical challenges to animals moving through them, leading to a variety of anatomical, behavioral and ecological consequences. Furthermore, many of these same principles may be applied to climbing without trees, such as on rock piles or mountains.

The earliest known tetrapod with specializations that adapted it for climbing trees, was Suminia, a synapsid of the late Permian, about 260 million years ago.

Some invertebrate animals are exclusively arboreal in habitat, for example, see tree snail.

Eye color is a polygenic phenotypic character determined by two distinct factors: the pigmentation of the eye's iris and the frequency-dependence of the scattering of light by the turbid medium in the stroma of the iris.

In humans, the pigmentation of the iris varies from light brown to black, depending on the concentration of melanin in the iris pigment epithelium (located on the back of the iris), the melanin content within the iris stroma (located at the front of the iris), and the cellular density of the stroma. The appearance of blue, green, as well as hazel eyes results from the Rayleigh scattering of light in the stroma, a phenomenon similar to that which accounts for the blueness of the sky. Neither blue nor green pigments are ever present in the human iris or ocular fluid. Eye color is thus an instance of structural color and varies depending on the lighting conditions, especially for lighter-colored eyes.

The brightly colored eyes of many bird species result from the presence of other pigments, such as pteridines, purines, and carotenoids. Humans and other animals have many phenotypic variations in eye color. The genetics of eye color are complicated, and color is determined by multiple genes. So far, as many as 15 genes have been associated with eye color inheritance. Some of the eye-color genes include OCA2 and HERC2. The once-held view that blue eye color is a simple recessive trait has been shown to be incorrect. The genetics of eye color are so complex that almost any parent-child combination of eye colors can occur. However, OCA2 gene polymorphism, close to proximal 5′ regulatory region, explains most human eye-color variation.

The red-eyed tree frog (Agalychnis callidryas) is an arboreal hylid native to Neotropical rainforests in Central America.