Wiki World: animals

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Study on Bony Fish, Sharks and Lungfish Clarifies Evolutionary Development

A study on lungfish, bony fish and cartilaginous fish has a great deal to offer in understanding development of legs for life on land. Lungfish are ancient ancestors of tetrapods - four legged animals. Walking on their fins and breathing air, lungfish bravely moved onto the land.

Research has relied on bones preserved as fossils, but muscles cannot be "saved" in this way. A fetus shows ancient stages in a creatures development. This is why a human fetus seems to be reptile-like in its early stages. Examining muscle development of modern lungfish is very informative. Tests were also done on cartilaginous fish such as sharks and ordinary fish.

Embryos of cartilaginous and bony fish were genetically altered to promote growth of precursor pelvic fins that in lungfish became legs. Engineered cells were made to emit red and green light. The study on muscles highlighted the fact that bony fish evolved legs while cartilaginous fish did not. Pelvic muscles of bony fish are a transitory stage between cartilaginous fish and land animals.

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Biology

Cats Door

"Hey stop shovin'"

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Funny Animal Photos

House Sparrows Discard Their Parasites When They Move to New Regions

The ubiquitous house sparrow found in just about every country is being examined by scientists. They successfully populate new regions by discarding their "companion" parasites. Though they force their way into new niches, they don't kill off native birds and animals with their resident parasites.

Sparrow parasites spread avian malaria. It seems that this disease is not spread to new areas because parasites that carry it are discarded. Without this deadly malady sparrows thrive.

House sparrows originally came from Western Europe. They successfully live alongside humans. The cheeky little birds get much closer than other birds to people. This enables them to get food easily.

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Biology

How Do We Select What to Pay Attention to?

How do we select which sounds to pay attention to? When we walk down a street we ignore the sounds of cars passing by, the gossip of people, and on, but we pay attention to a short, sharp whistle. Even little children know the sound of the ice cream truck.

Psychologists have been trying to find out how we select some things over others. Our brains record everything. Hypnosis has shown this to be true. We could not possibly take note of everything around us. Attention allocation operates by combining two functions: the predictive principle and the uncertainty principle.

The predictive principle is logical in that the brain searches for the more meaningful from the background "noise".

With the uncertainty principle the brain looks for the unusual, the odd thing out.

Animal research has shown that they do use both principles. However, tests on humans had clearly shown the predictive principle at work but not uncertainly. New tests show humans use a variant of the uncertainty principle called negative transfer. This involves ignoring new associations (outcomes) to a cue once a particular association has been learned. In other words new associations take longer to register in humans. The more "severe" the new association the quicker the uncertainty principle kicks in.

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Society

Vets Have Demanding Jobs and Don't Get Paid

People expect treatment of animals to be free. This is a fact. That is why there is a high suicide rate for veterinary surgeons. The suicide rate for vets is four times higher than the rest of the population.

In cities people take their pets to the vet when there is serious injury or illness or when an animal is at death's door. If their pet dies while being treated or operated on it is the norm, expected, that the vet will wave charges. And again, after a pet is put down it is deemed to be rude for the vet to charge a reasonable fee.

Rural regions operate in a different way. Veterinary surgeons are on duty 24 hours a day, 7 days a week. At lambing time they are rushed off their feet. Every farmer pays 3 months after service, so vets are in debt to the bank from the start. The days of paying with eggs are not gone either. Meat is often offered as payment.

Why do people train to be vets? They obviously love animals, like the technical side of the job, or have community spirit. They will not become wealthy nor have secure futures.

~~~~~Animals~~~~~

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become wealthy or have secure futures.

New Jellyfish in Coffs Harbour

It seems humans know just about everything. This is a myth really. A new species of jellyfish has be seen in Coffs Harbour, NSW. It seems the marine creature has been there for a long time.

The mystery "object" is a box jellyfish that appears to be totally harmless. It is unlike the Irujandji and is smaller than the dangerous Chironex flecker box jellyfish. Fishermen have been seeing the new jellyfish for sometime but authorities took no notice. A game crew took photos of the animal last week.

Finally "professionals" acted and arrangements are being made to catch some specimens. Fish of all kinds are moving south as the temperature of the ocean increases due to climate change. It is believed the visiting jellyfish come from more northern climes. Usually jellyfish do not move south because they can be harmed by rougher seas. They prefer the warm, calmer tropics.

~~~~~Science~~~~~

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Extinct Animals Are Still With Us

Animals are going extinct, though some are still turning up. This is true. In the past 100 years many species have been declared extinct. Oddly, a third of these have been found still living. Many have not been seen for a very long time. This is the reason for them still being around.

The okapi a zebra-like animal was recently re-found in the Congo. In Cuba the solenodon "rat" was seen jumping around. Another find was the Indonesian Talaud Flying Fox. In Australia the rock rat was identified. And the Christmas Island shrew came to light.

This is embarrassing for the conservationists about to meet in Japan at the United Nations Summit on Biodiversity. It appears that emotion has won out over rationality. It is too easy to make predictions about what will happen in the future. With climate change, little real knowledge is available to researchers. Perhaps now more cautious steps will be taken.