Wiki World: biology

Showing posts with label biology. Show all posts

Higher Carbon Levels in Sea Water Changes Hermit Crab Behavior

More research is proving that the theory of animals becoming bolder with climate is correct. Sea water is retaining more carbon dioxide. This is altering the body chemistry of some animals.

Tests were done on the hermit crab and a "toy" of its main predator the octopus. In a laboratory, hermit crabs were split into two group and put into aquariums. The water in one aquarium was at a pH of 7.6; the other had a pH of 7.1. This may seem to be only a small amount of difference in acidity but it was significant on behavior.

The flicking of antennae (testing for danger of preying animals) and oxygen levels were measured. The hermit crabs in the more acidic pH 7.1 water flicked their antennae less often. Crabs in the 7.6 aquarium definitely responded much quicker when a toy octopus was dipped into the water.

Visitors at the Third International Symposium on the Ocean in a High-CO2 World had a good laugh at the crab behavior. A more serious problems could be the declining level of safe hermit crab abodes. Higher acidity is dissolving abandoned shells that hermit crabs jump into and carry around as homes.

http://www.adventure--australia.blogspot.com/
http://www.tysaustralia.blogspot.com/
http://www.feeds.feedburner.com/AdventureAustralia
http://www.technorati.com/blogs/
http://adventure--australia.blogspot.com

. . . . . . . . . . . . . . . . . .

Marine Biology

Scout Bees Have "Curious" Brains Like Humans

It was thought that bees were like robots who went about their work on instinct alone, but some bees have "curious" genes. The scouts who find sources of food are actually mischievous seekers. Their genes give them a brain structure similar to humans.

Scout bees are independent creatures who don't go along with the mob. They find new food sources by intuition and pure skill. Being female, they go back to the hive do a wiggle dance to pass on directions, then go out again to find a new source.

Tests were done on a hive of bees. The hive was put into an enclosure and food was put out in different colored jars. Bees that located the jars were collected and marked with a dot of paint. Later the brains of these scout bees were removed and compared with the brains of normal hive bees. Brain activity in the genes of the two types of bees differed by 16 per cent. The brains of scouts could change the levels of neurotransmitters dopamine and glutamate. Another test was done with the scouts being fed sugar water laced with a neurotransmitter "booster", The scouts became more active in their search.

This proves that dopamine and glutamate are responsible for curiosity in humans. The common ancestor of bees and Man was a marine flatworm. These basic animals would not have had scouts, so the "curious" genes developed in both lines, bees and Man, separately. It is also probable that the gene variant can become active in any animal: it is latent in the gene toolkit.

. . . . . . . . . . . . . . . . . .

Biology

Whales Sing a Different Song

It was believed that all whales spoke the same language like a bird species, for example, where all the birds have the same song. New observations show that whales sing different songs depending on where they live in the world.

Humpbacks on either side of the Indian Ocean do not sing the same song. Western Australian whales would not be able to "understand" whales in Madagascar. The two groups have been isolated from each other for a long time.

It would be expected that whales in the Northern Hemisphere and the Southern Hemisphere would differ, but the Indian Ocean whales are quite close to each other. The southern whales only have one similar song theme. A song is a series of themes.

. . . . . . . . . . . . . . . . . .

Biology

Tasmanian Glow Worms Can Tell the Time

Glow worms can tell the time. Yes it's true! An Australian researcher has found that glow worms "light up" during daylight hours, even though they are in total darkness 24 hours a day.

It is only a Tasmanian species of glow worm, however. Mainland species glow day and night. It is not known how they detect that it is daylight outside the cave.

It is thought that a chimney effect occurs in a cave, whereby air is "breathed" in and out from outside. This probably causes a change in temperature. Glow worms possibly use the temperature stimulus to choose when to glow and when not to glow.

. . . . . . . . . . . . . . . . . .

Biology

Baby Turtles Communicate So They Hatch Together

Baby turtles hatch all at the same time. This is no accident: they communicate with each other while they are still buried under the ground. Some eggs are deep down where it is cooler. Others are near the surface where the sun heats the eggs up. As hatching gets closer those further down speed up their development while those higher up slow down.

University of Western Sydney researcher Ricky-John Spencer randomly collected turtle eggs then put them into two groups. One group was incubated at 25 degree Centigrade, the other group are 30 degrees. They were then all brought together and kept at the same temperature: they all hatched at the same time.

Jessica McGlashan took a closer look. She brought a female turtle into the lab and collected the eggs the turtle laid. One half of the eggs were put into the incubator at 30 degrees, While the other half received 26 degree incubation. Some eggs from both temperatures were then put into one group in the incubator at the higher temperature and those who had been initially incubated at 26 degrees were tested. They did indeed develop faster.

A group eggs was kept at 26 degrees throughout. As the days went by the faster developing embryos who were now at 30 degrees exhaled more carbon dioxide and their heart rates were faster than the embryos kept at 26 degrees.

Baby turtle don't actually communicate verbally, but they can "hear" each others heart beat, or rather feel the vibration of heart beats because the eggs are touching. They could even be measuring the carbon dioxide level.

. . . . . . . . . . . . . . . . . .

Biology

New Dolphin Species Found in Australia

It is amazing that a species of dolphin has been living along the coast of Australia and scientists did not know it - until now. The Burrunan dolphin is the third new species to be identified since the 1800s. Named Tursiops australis, the new mammal is represented by two small groups living among bottle-nosed and common dolphins living off the Victorian coast.

They are quite distinct from other dolphins having different body shape, skulls and DNA sequence. The discovery came as quite a shock and shows that new species of other animals could be living unidentified in regions already extensively examined.

Man may be going into space but much of our planet still remains unexplored. New species still need to be classified in South America. The behavior of some creatures is not yet fully understood. For example, giant catfish in Asia are suspected of taking people swimming across rivers.

http://www.adventure--australia.blogspot.com/

http://www.tysaustralia.blogspot.com/
http://www.feeds.feedburner.com/AdventureAustralia
http://www.technorati.com/blogs/
http://adventure--australia.blogspot.com

. . . . . . . . . . . . . . . . . .

Biology

New Genomes Could Be Dangerous

There is a lot of excitement about synthetic biology. That is the creation of designer organisms. Many people are concerned, however, fearing the making of monsters that cannot be destroyed, but new developments improve health care and reduce the reliance on non-renewable resources.

New body parts are being made from a patient's own stem cells. GM food crops have been accepted after some early resistance. There are clear benefits for society from these scientific achievements. What is not so clear are the possible dangers from creation of completely new genomes to produce fuel, food, polymers and drugs.

Making new life forms that could reproduce is the area which frightens most people. There isn't much doubt that science will progress. At the moment purpose built creations are limited to 10 genes. This barrier will soon be surpassed.

There is always danger that new things will be misused. We will just have to hope that rules and regulations will prevent this. It seems that science will continue to move forward and not much will be done to stop technical advances.

. . . . . . . . . . . . . . . . . .

Science

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.

. . . . . . . . . . . . . . . . . .

Biology

Subscribe to: Posts ( Atom )