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How does our vision compare to some animals?
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Do animals see the same way we do? Do some animals have better vision than humans? The senses of animals have evolved to give members of the species an optimum chance for survival. Here are a few examples: Some animals, such as cats, have a reflective surface ( tapetum) on the back of the eye behind the sensory receptors (left image above). When light first enters the eye, some light is detected by the sensory receptors. The light not detected by the sensory receptors continues onto the reflective surface at the back of the eye. This light is then reflected outward toward the sensory receptors, providing a second opportunity for detection. This feature produces two results. First, the outward reflection results in the shining of the cat's ey ...
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14918 |
Biology Forums |
A year ago |
Teeth that never stop growing
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Rodents are mammals characterized by a pair of broad, sharp-edged, chisel-like incisor teeth that are firmly inserted in both jaws and are used in gnawing vegetation. The front surface of each incisor tooth is composed of enamel, and the hind surface is of soft dentine wears away during the process of gnawing so that the teeth are constantly kept sharp. Shown above is a beaver sporting bright orange teeth; the reason they are orange is because of an unusually high concentration of iron in the enamel. Unlike human teeth, the incisors of rodents don't have roots, and they never stop growing! To keep these teeth from growing into their brains, rodents grind their teeth against each other. This friction is similar to using a grindstone to sharp ...
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5830 |
bio_man |
2 years ago |
Wholphin: a fertile hybrid
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A wholphin is a rare fertile hybrid born from mating a bottlenose dolphin ( Tursiops truncatus) (mother), and a false killer whale ( Pseudorca crassidens). Although they have been reported to exist in the wild, the first captive wholphin was born in 1945, where a bottlenose dolphin and a male false killer whale shared a pool. The wholphin's size, color and shape are intermediate between the parent species. For example, an adult wholphin has 66 teeth - intermediate between a bottlenose (88 teeth) and false killer whale (44 teeth). They are smaller than a false killer whale but are larger than a normal bottlenose. Normally, when two different, yet similar species mate, such as a female horse and a male donkey forming a mule, the progeny is expec ...
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6478 |
bio_man |
2 years ago |
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11371 |
bio_man |
3 years ago |
"Give orange me give eat orange me eat orange give me eat orange give me you."
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That's the longest string of words that Nim Chimpsky, a chimpanzee who scientists raised as a human and taught sign language in the 1970s, ever signed. He was the subject of Project Nim, an experiment conducted by cognitive scientists at Columbia University to investigate whether chimps can learn language. After years of exposing Nim to all things human, the researchers concluded that although he did learn to express demands - the desire for an orange, for instance - and knew 125 words, he couldn't fully grasp language, at least as they defined it. Language requires not just vocabulary but also syntax, they argued. "Give orange me," for example, means something different than "give me orange." From a very young age, humans understand that; w ...
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15492 |
duddy |
7 years ago |
One hairy situation
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The hairy frogfish ( Antennarius striatus) is a marine fish with spines resembling strands of hair - and it can change color. This small fish grows up to 22 cm (8.7 in) long, and has a rounded, extensible body. Its large mouth is forwardly extensible, allowing it to swallow prey as large as itself! The coloring of its body is extremely variable because individual fish tend to match their living environments. Frogfishes have the capacity to change coloration and pigment pattern, taking only a few weeks to adapt. The dominant coloration varies from yellow to brownish-orange, passing through a range of shades, but it can also be green, gray, brown, almost white, or even completely black without any pattern. Body and fins can be marked with roug ...
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7163 |
duddy |
7 years ago |
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5321 |
duddy |
7 years ago |
This beautiful white coat serves as a perfect camouflage
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The arctic fox is an incredibly hardy animal that can survive frigid Arctic temperatures as low as –58°F (-50°C) in the treeless lands where it makes its home. It has furry soles, short ears, and a short muzzle - all-important adaptations to the chilly clime. Arctic foxes live in burrows, and in a blizzard they may tunnel into the snow to create shelter. Arctic foxes have beautiful white (sometimes blue-gray) coats that act as very effective winter camouflage. The natural hues allow the animal to blend into the tundra's ubiquitous snow and ice. When the seasons change, the fox's coat turns as well, adopting a brown or gray appearance that provides cover among the summer tundra's rocks and plants. Source: http://animals.nationalgeographic.com/ ...
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23506 |
duddy |
8 years ago |
A rare albino whale sighting
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Migaloo is a rare albino humpback whale found near the coastlines of Queensland, Australia. Adult humpbacks range in length from 12-16 metres (39-52 feet) and weigh approximately 36000 kilograms (79,000 lb). For more information on Migaloo, visit http://migaloo.com.au/.
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2196 |
duddy |
8 years ago |
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1803 |
duddy |
8 years ago |
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1849 |
ehd123 |
8 years ago |
Humans and Earth - the battle
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When you turn on your TV, it is the definition of ironic to watch the news channels for information about planet mass destruction. Whilst when you step outside your door, it is quite alarming and obvious that our earth is suffering. When every person around you, from toddlers to elderly, own some for of technology, with no means of recycling old items. When students, each with their own copies of pages. When potable water has not yet reached the most needy of nations. When human greed is apparent with every innovative idea claiming to "revolutionize "a domain brought up to make a quick buck. Drilling, mining, industrialization, politics, scavenging for resources, suffocating our environment... This may all seem negative, but coming from a ...
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2745 |
ehd123 |
8 years ago |
Watch this ex-circus lion feel grass for the first time
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This lion, named Will, spent his life with a traveling circus in Brazil. "For 13 long years, the lion had been confined to a cramped cage and denied any semblance of a normal existence," the Sao Paulo sanctuary wrote.
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1610 |
duddy |
8 years ago |
Kermit's ancestor
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The Hyalinobatrachium dianae glassfrog was just discovered! And people are saying he looks familiar.
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27125 |
duddy |
8 years ago |
Ever seen a black flamingo?
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On the Mediterranean island of Cyprus, you might be lucky to find a black flamingo. Normal flamingoes are born white and grey, and turn their iconic shade of pinky orange around the age of two, as a result of the high carotenoid content of the algae and crustaceans that they eat. Experts believe that this individual (and potentially the other bird spotted in Israel) has a genetic condition that causes it to overproduce melanin, changing its feathers to black.
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21729 |
duddy |
8 years ago |
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