本部落公告

Welcome
2008/11/21

How many species on earth?

Although the human and other biological have been living together on this planet, but we know the extent of these neighbors is an alarming lack of - we still can not even determine the survival of the planet in the end how many species of animals and plants.

Environmental impact of the number of species

According to the National Science Foundation "Tree of Life" project to statistics, there may be 5,000,000 to 100,000,000 kinds of biological survival on Earth, but scientists can determine, only about 2,000,000 kinds. California Academy of Sciences entomologist Brian - Fisher believes that only accurately calculate the number of organisms on Earth is not the most difficult task, it is difficult to carry out these biological classification is a classification of existing organisms found on Earth , And describe the different categories of science, is "the cornerstone of understanding of life on Earth." Fisher said: "We should have an environment in which the Dow Jones index to evaluate other human activities on the biological impact. We also understand the animal's life is very shallow, only just discovered the earth 10% of the existing species. "

The current understanding of the human being and what life together to share the earth is of great significance for us because of global warming, deforestation and other signs of human development is a threat to these populations, and these populations is essential to the balance of the ecosystem, Precious human development. To Africa as an example, a 2001 study found that Africa as a matter of fact by two different genetic characteristics of an elephant, namely Africa and Africa as low as. Now, these two species are classified as endangered species. A new tropical butterflies situation is typical, after genetic analysis, they were from 10 different species lurking. World Wide Fund for Nature has warned that if the global average temperature in 1990 on the basis of the high-rise 2-3 degrees Celsius, some of the species is likely to be in human cognition will be before the extinction.

The exact number is difficult to calculate

Over the past 250 years, although taxonomists have been carried out on a variety of animal and plant categories, but they still can not answer the question: "Earth in the end how many species?" Can not be accurately calculated for the species is one of the reasons why We discovered and described a large number of biological belong to a very small number of areas: insects, bacteria and other micro-organisms. American Museum of Natural History in New York's Joel - La Fute Kai Lake, said: "We have done a lot of work to fly over the size of the animals are classified, but we contrast the small flies but little is known about the animal." For The redrawing of the species is not just an academic issue. In the early 20th century, the division of the mistakes made by the mosquito species of malaria control has led to confusion. Was originally classified as a species of mosquito has included 6 different types, and the spread of the disease, only one of the 3.

A further reason is that in developed countries, the taxonomy conducted in a relatively consistent place in the Southern Hemisphere countries, as economic underdevelopment, a large number of various species will not be able to get a good classification. Fisher said: "Our Earth, the uneven distribution of the species, and some species relatively prosperous area, and some relatively rare species in the region." For example, the American Museum of Natural History entomologist Randall - Shuhe That the North African species of insects known about 2000, and Australia, only 200, but according to his Australian plant species sampling analysis shows that Australia should be at least 3000 kinds of insects.

In addition, the "mystery" so that the taxonomy of species is also complicated because in the eyes of humanity appears to be the same species have different genes in fact, it is difficult to be classified. Shu He said: "When we see into the nature of individual organisms, we can not distinguish between them because they did not have any standard name and will not tell us what they are animals. Some species appear widespread, the number of Many, but in reality, they may be hidden by a number of different groups formed, each of them lurking in the number of species are low, and even on the brink of extinction. At present, scientists do not know how much in the end kind of hidden, it is necessary to To know the exact answer, unless at least one of the taxa in the species analysis of genetic information. "

New technology to identify species

At present, the taxonomists have mastered a new technology research, such as can easily distinguish between species, in particular the "mysterious species" and small species of DNA sequencing technology. Over the past 20 years, thanks to the growing maturity of the DNA sequencing technology, access to other species of human genome more and more, the scientists found lurking in the number of species also increased drastically. In addition, biologists have also been involved in, such as the "Tree of Life" and other research projects, such as Shu He is committed to leading the research bug "biodiversity of the planet directory", as well as by more than 70 countries participate in the assessment of the marine biological diversity And the "Census of Marine Life," aims to identify the millions of species on Earth, their classification and to identify their pedigree. Fisher said: "Through continuous efforts, I think we can find on earth to survive with the other 90% of the biological species."

繼續閱讀
2008/11/21

The Animal kingdom's Most

The myth of animal world!
In 1846, two dry desert snail's death was sent to the British Museum of Natural History, in a stick of wood taken in the exhibits. Four years later, the museum staff suspected that a snail's still alive, so they will take it from the board down into warm water. Thelittle things went so far as to the activities in the water, then food Chi Qi. It lived for the past two years, sleeping, and died soon after. The snail "resurrection" of something until today so that scientists are at a loss.

According to scientists in the United Kingdom in 1990 to obtain the results of research animals in 4.14 billion years ago miles from the climb up the land. In the first land-based animal habitat, there are two types centipede grass and a spider, as far as 3 kinds of animals that evolved very fast. Since the emergence of animals on Earth, something unheard-of animals in the world on many anecdotes.

Central and South American monkeys roar of the animal kingdom, is the favorite animal noise, the throat bone structure so that the monkey hung roar of voices loud special. It is the plaintive whine Quanfei audio-visual and sound mixing bray, but the volume has increased a thousand times, so when it is loud moan, can be heard 5 kilometers.

Other animals can cause great harm to the cat family beast on earth is the most dangerous animal it? Is not. Experts say the most dangerous in a normal circumstances, can not see the silence of the biological: Anopheles parasites in the body of the parasite. In addition to war and disaster, malaria may be the Stone Age, human beings face the biggest killer since the death of half of it. When we refer to the most toxic animals, had a similar situation. Snake bites of the most lethal poison it? Tarantula spider, or else the most poisonous spider it? Not right. Latin America color of a small frog's body contains one of the most lethal venom. Western Colombia a golden frog, the frog's secretion of other drugs is the most: as long as it has in other efforts like the frog skin, is enough to kill them home.

Blue whales and fin whales in contact with each other when the low-frequency sounds to reach 188 db with specialized equipment to test, 850 km away can hear their voices, is the world's most resonant voices of animals. Compared with the load on the body, known as a tropical scarbaeidae large beetles greatest strength. Packtrain it is the weight of their body weight 850 times, one can back up the weight of up to 17 times the weight. In the fecundity, the aphid food is the undisputed champion. If there is adequate food, the animals did not appear hostile, it is estimated that a dish in the aphids one year of breeding future generations in theory could reach a total of 822,000,000 tons of weight.

According to the diagonal measurement of the shark bite force showed a 2 m-long shark Kok of the frontal force can be 60 kg, which is equivalent to its teeth pressure for 3 tons per square centimeters. It is estimated that the other large sharks, such as the great white shark, a greater bite force. Animal World is the most sensitive sense of smell is the king of animals butterflies, butterfly-hung Wang 11 kilometers will be able to smell the female butterfly king who issued a strong appeal to the odor. Renewable sponge is the most resilient animals, as long as it's a small piece of the body can regenerate the body, if a sponge is divided into only a few millimeters of small, it will be able to grow a new sponge. Atlantic octopus in the eyes of the world's largest animals, a large Canadian waters of the octopus eye has a diameter of 500 mm.

The largest group of mammals from the western United States and Mexico and the northern part of the end of the prairie dog component. In 1901 found a black tail prairie doggery estimated to be 400,000,000 dogs, they are active in the 61,000 square kilometers of land.

July 20, 1875 to 30 days a group of locusts flew over Nebraska, USA, which is known to mankind so far the largest group of animals. The group of locusts covered an area of 514,400 square kilometers, it is estimated that these locusts have a total weight of 25,000,000 tons.
發表於 2008/11/21 03:31 PM
繼續閱讀
1