How many species of biological organisms have been discovered so far?

[hallenrm]

After elements and forces it is now the turn for bio-organisms. The number must be very large.

 

Does anybody around knows the exact number? If no, never mind just guess it! And while you are guessing why not ponder about the question:

 

What really is a biological organism as well! :shrug:; Is it just another name for large organizations of biomolecules? I had initiated a thread on that also!

 

Happy guessing and thinking. :)

[Boerseun]

According to the Pear's Cyclopedia (1998), around one million species have been described and classified, with hundreds of new ones being added each year.

 

Can't give you an exact figure, though.

 

The scientist who wrote the Pears article estimates that there might be as many as ten million additional unclassified species.

[somebody]

i though there were more species on earth than million. I learned in my bio class that BUGS RULE since class insecta has thousands of different species and no to recall marine organism.

[hallenrm]

According to the website of Canadian biodiversity council

 

http://www.canadianbiodiversity.mcgill.ca/english/species/index.htm

 

There are currently between 1.5 to 1.8 million named species in the world, about half of which are insects. The largest group of insects is the beetles (the order Coleoptera), with 300 000 species. In contrast, there are only 4 500 species of mammals.

 

These numbers are just for the known and named species. No one knows how many species are still to be discovered. Estimates for the total number of species on the planet range from three million to 100 million, though most generally accepted estimates are between five and 20 million.

 

As per the website

 

http://www.enviroliteracy.org/article.php/58.html

 

There have been a number of efforts to estimate the number of species that are known and have been described. This is a challenging job because there are no central registries for species, and no one database. Often species that have been described by scientists in one geographical site, are also recorded and described by scientists at another. It takes time and research for biologists to recognize these redundancies. In addition, scientists have different opinions about what constitutes a species or a subspecies. Biologists define a species as a population that interbreeds under natural conditions. However, there are ambiguities in this definition that add to the difficulty of enumerating species, even those that have already been discovered.

 

Any suggestions how this mammoth task may be achieved? :)

[Ganoderma]

We need to get a better understanding of taxonomy. One species may be considered another by a different athority, this alone would make any "real" number of species questionable. Insects are especially known for having unknown classification and are often put into a number of different species by different taxonomists.

[Michaelangelica]

The number keeps going up especially when we discover a new space.

 

The volcanic vents at the bottom of the sea;

the various levels of life as you move vertically in a rainforest

and lately the nuclear industry has been finding bacteria down 2+ mile shafts drilled into the earth.

 

Traditional knowledge is also being re-assessesed too. Recently it was discovered by Harvard biologists/botanists that Amazon shaman seem to be able to distinguish/classify different plants in situ where botanists can only classify/distinguish them using a modern, high-tech laboratory

 

Recently a"Lost Valley" full of new life- including rare monotremes- was discovered in Papua by a team of biologists from Adelaide Uni

 

(The way Indonesia is raping Papuan forests we need to be quick to get some stuffed examples for museums) :hihi:

[Ganoderma]

some shamans claim they can distinguish plants by the messages tehy tell them when ingested. Banisteriopsis caapi some say have 7 different kinds, while botanists often say say 1. there are many ways of classifying things, and it seems every way argues against the other ways. This will often lead to the same specimen been placed into 2 or more species, or even genera.

 

Michaelangelica, you ar efull of links, got any on those bacteria 2+ miles down? was this in dirt, rock, what?

[hallenrm]

Let us face the problem in a slightly different manner, all biological organisms have on thing in common, that they have the same kind of herideritay material DNA molecules. The DNA molecules of the different species differ only in the length of the DNA molecules, the sequence of the bases that make up them and the number of chromosomes.

 

Now is it possible to calculate statistically how many kinds of bioorganisms can or could have existed?

:hihi:

[Michaelangelica]

Michaelangelica, you ar efull of links, got any on those bacteria 2+ miles down? was this in dirt, rock, what?

From memory, bacteria were in rocks. The nuclear industry have been looking for sterile areas to store waste and have , to their and everbody's else's amazement, not been able to find an area free of bacteria.

Here are a couple of links from a google search:-

http://www.spacedaily.com/news/life-02k.html

Microbes May Survive 50 Miles Down

 

(illustration only) Using the tools of high-pressure physics to microbiology by using diamond anvil cells to subject two bacteria species—-E. coli commonly found in the human gut, and the metal reducing Shewanella oneidensis—-to pressures up to 16 thousand times the pressure found at sea level.

Moffett Field - Feb 26, 2002

Until now, scientists thought that only specially adapted organisms they call extremophiles could exist in seemingly intolerable environments such as high-pressure, high-temperature oceanic hydrothermal vents or in the ice sheets of Antarctica.

 

A study published in the February 22, 2002, issue of Science, however, shows that even common bacteria are viable under high-pressure conditions equivalent to about 50 kilometers beneath the Earth's crust or 160 kilometers in a hypothetical sea.

 

This finding may expand the habitable zone for life within the solar system and it opens new doors for looking for life much deeper inside planetary bodies than previously considered.

. . .

For some time there has been mounting evidence that a large portion, if not a majority, of life today exists in the deep subsurface (including in deep frozen lakes and the ice caps on Earth). This along with other recent findings should be taken into account when focusing on the survivability of life elsewhere. "Soon the only thing that should limit our investigation of the survivability of life on Earth and beyond is our imagination," concludes Scott.

Extremophiles

Extremophiles are microbes that live in conditions that would kill other creatures. It was not until the 1970's that such creatures were recognized, but the more researchers look, the more they discover that most archaea, some bacteria and a few protists can survive in the harshest and strangest of environments.

 

addition, the research into extremophile microbes has led to the confirmation that the new domain of living organisms - the archaea exists. Archaea are not the only extremophiles, there are some eukaryotes that live in such conditions.

 

Microbial life has been found living:

 

# in the cold of the Arctic and Antarctic - ice lovers

# in volcanic vents on land - thermophiles

# on the ocean floor - thermophiles

# in very dry places - Dry and hot, dry and cold

# in hot volcanic vents of the deep ocean - thermophiles

# in rock, deep inside the Earth - rock dwellers

# in severe chemical environments harmful to most life-forms - acid, alkali and salt

# in high-radiation environments, such as on the control rods of nuclear powerplants - the toughest...

# for very long periods of time - timetravelers

. . .

Rock Dwellers

Archaea have been found more than four miles down, in the ancient lava flows of the Columbia River area of Washington State, by a NASA microbiologist . They live inside the rock itself and respire anaerobically. The pressures at these depths are over 14 tonnes per square centimeter (approx 70 tons per square inch). The bacteria feed off hydrogen gas which is given off when water seeping through the rock reacts with it. The bacteria look very similar to the Mars meteorite fossils. On Mars a similar site would have protected its living organisms from the harmful radiation that is present on the surface of the planet.

 

Nanobacteria have been found at extreme depths in the seabed sandstone off Western Australia, as shown in this image (right). Again these survive at extreme pressures.

. . .

There is growing evidence that the ground beneath our feet is not just home to a few odd archaea and bacteria, but is the habitat of trillions of microbes. Additionally, it seems to have provided a comfortable home for them for a long time - perhaps life even started in the depths below. The evidence comes from analysis of minerals.

. . .

 

http://www.theguardians.com/Microbiology/gm_mbm04.htm