how do classification systems help us to think about and study diversity on earth?
824928
Taxonomic classification systems are useful for a couple of significant reasons.  First and foremost, it creates a name for each living organism that ALL scientists can agree upon.  Therefore, biologists on opposite sides of the world can be confident that they are discussing the same organism when looking at the taxonomic label of that organism.  Secondly, the design of the system is useful for showing evolutionary relationships among organisms.  Generically, the breakdown is kingdom, phylum, class, order, family, genus and species.  There are five kingdoms (six in some systems) and millions upon millions of species.  For any two organisms, they are more closely related evolutionarily if they share a classification more toward the species.  For example, two organisms that share a genus are more closely related than two other organisms that only share a family.  You should know that there modifications of the above system so that you get things like subphyla, superfamilies, etc.  The genus and species names are GENeral and SPECIfic for a particular organism and are always written in italics, with the genus name being capitalized and the species name beginning with a lower-case letter.  The millions of species described by the system is a testimony to the great biodiversity of life on this planet.
28768
Here is a great website for that sort of research. It has a taxonomic chart with hyperlinks to information, pictures, sounds, and specimens. There are more than a dozen phylums of 'worms' represented with many photos to help with identification. \n\nhttp://animaldiversity.ummz.umich.edu/site/accounts/classification/Animalia.html
303798
There are more described species of insects at present, but it's unlikely that this is representative of the actual diversity of the organisms.\n\nInsects are easier to distinguish using visible characters, and there's more economic impact of various insect species, so there's more incentive to work on them.  \n\nWhile there may be millions of different species of bacteria, they are harder to distinguish from each other, except possibly by comparing genetic material.  So no one has actually done the work necessary to categorize all of those species yet.
1168604
Depends where you look. We don't have records long enough to look at the statistics of earthwuakes for the whole of the Earth.\n\nHowever, over time, some areas become more active and some less so.
659956
We have catalogued an estimated less than half the species out there- And once catalogued, we don't have an active system to determine populations of most species.  Thus, we are in the dark about what species are there, how many there are in the population, etc.  GIven that, we have only vague guesses about the number of species lost.  In a similar vein, we assume new species are being born each year, or at least each decade, but since we don't know what species were there before, we certainly can't tell if a species is newly evolved, or is just one we have never seen before.
1071865
Your question is actually a really good one.  Basically, you could extend it and ask "What makes any biological group a group?"  It's a field of inquiry that biologists call "taxonomy".  Its objective is to organize living or extinct species according to their relationship, i.e., their shared evolutionary histories.  \n\nAs you may know there are different levels of groups, or, as we say in biology, taxa (one taxon, many taxa).  The perhaps most easy one to envision (at least seemingly so) is the taxon "species".  Our species, Homo sapiens, is one taxon, since all members share certain characteristics, go back to the same origin (ancestral species), and are genetically not isolated (which means, they can produce fertile offspring together).  The next level up would be genera.  Latin names indicate both the genus and the species. In our case the genus would be 'Homo' and the species 'sapiens'.  We have no sister species in our genus, but in other genera there can be numerous species.  Take for example fruit flies.  The genus is 'Drosophila' and is comprised of a variety of species, with 'melanoptera' being perhaps the best known.  \n\nThe problem with taxa is that we are reconstructing their relationship as well as themselves based on our understanding of their biology.  And that is of course never complete.  Using a particular method of comparison of numerous characteristics, ancestral trees can be created to represent how the species evolved and how they are related.  In the genus Drosophila there are numerous species, but throughout their evolutionary history they all originated in one ancestral species, from which other populations branched off and eventually became their very own species.  All members of the taxon 'Drosophila' are monophyletic, which means that they indeed are closely related by origin (i.e., shared ancestor species).\n\nNow, to answer your specific question of what makes a dinosaur.  Someone suggested here that they were reptiles.  A good idea, if only 'reptiles' were really one of those 'monophyletic' groups.  But in fact, they are not.  recent research has shown that those critters we once all subsumed under the term 'reptiles' are actually not at all closely related.  Crocodiles and alligators, for example, are closer related to birds than to snakes.  They form a monophyletic taxon with birds, but not with their fellow 'reptiles'.  Ergo, that criterium 'reptile' is not a very good one.  Then, what are dinosaurs and what makes them a monophyletic group?\n\nThe Dinosauria are a monophyletic group characterized by the following autapomorphies (that are characters shared by all members of the group, in that case all dinosaur species):  elongate vomers, three or more sacral vertebrae, scapulacoracoidal glenoid facing fully backwards, low deltopectoral crest running 1/3 to 1/2 way down humerus, three or fewer phalanges on fourth digit of manus, largely to fully open acetabulum, fully offset proximal head of femur with a distinct neck and ball, greatly reduced fibula, well-developed ascending process of astragalus; upright posture, digitigrade stance.  In a cladistic investigation of a recent taxon (i.e., one that is still alive and not exitincet) taxonomists would also include genetic characteristics, but for extinct species that is a bit difficult (to say the least).  \n\nAt any rate, the list of anatomical characteristics given above gives you the main autapomorphies for the Dinosauria I could find.  Previous classifications usually considered dinosaurs a polyphyletic group with independent origins from thecodont ancestors. Dinosauria are now considered by many monophyletic, because of these numerous autapomorphies.  \n\nIf we found a living species that would also have these characteristics, we would indeed have found a dinosaur.  Extinction is therefore no criterion for taxonomy.  But so far,
580285
No, classification is done by domain, kingdom, phylum, order, family, genus, species, subspecies
1129610
It helps you with the classification of items. I assume you are referring to a taxonomy you might find with some XML files. Sorry if I am mistaken, but I will assume that is what you are referring to.\n\nA great example of a taxonomy file would be one that refers to our planet for instance. At the top is the "World" which may have seven continents. Each continent would have all the countries on that continent. Each country would have its capital city. You get the idea.\n\nWith this in mind, here are some advantages:\n\n1) It could be used for verification purposes, to make sure you have all the data needed. For instance, your taxonomy said there should be an Australia component, but no Australia data was found.\n\n2) Quick lookup. Since a taxonomy lists everything and categorizes it into a hierarchical fashion, you can quickly jump to World/Europe/Italy to find Italy's capital.\n\n3) Presents a high overview of large amounts of data. Shows you how complex data items like a "country" fits into the world. \n\n4) It is a simple catalogue of all items. You could loop through a taxonomy XML file and list the entire contents of all the countries/capitals in the world using just one file.\n\n5) Lastly, can help identify what an item is quickly. I see the Belgium is apparently a country in Europe which is part of the World.\n\nThese are some of the advantages that a taxonomy can offer you. I like to think of taxonomies more like an index of a book that tells you on which page you can find the subject you are looking for.\n\nAgain I am sorry if an XML taxonomy is not quite what you were asking for. Hope it helps!
147799
Scientists now use a systems view of Earth to understand the processes responsible for the evolution of the Earth on all timescales and the interaction of Earth's subsystems (atmosphere, biosphere, geosphere, hydrosphere). Understanding Earth means using a scientific approach that considers the Earth as a complex, evolving body, characterized by ceaseless change. It means understanding Earth on a global scale by describing how its component parts and their interactions have evolved, how they function, how they may be expected to evolve. \n\n\nWe are interested in how the Earth system functions, what is "normal," what causes change in the system, and how the system copes with change. The Earth system is sometimes compared to the human body. We are interested in how well our heart/ lungs/muscles/nerves, etc. work--but we are most keenly interested in how well the components work together--our overall health. So it is with Earth. \n\n\nDisturbances to the Earth system are called perturbations. They can encompass anything from a change in the amount of solar insolation reaching Earth to the amount of carbon dioxide humans are putting into the atmosphere. Any change that has an effect on the Earth system that is either amplified or damped is part of a feedback loop--either positive or negative. Positive feedback reinforces an action or response. For example, an increase of ice or snow in cold climates can encourage cooler temperatures and more ice and snow--a positive feedback. Negative feedback is usually more stabilizing and limits the deviation of the system. For example, if those cold climates had warmer temperatures, that would likely result in less ice and snow, which would encourage the continuation of warmer temperatures. Notice that positive feedback reinforces (amplifies) a behavior but does not mean that the behavior is desirable. See Daisyworld on page 9-13 for a more detailed look at systems.
656130
No. Even if the human race moves-on to distant planets, the universe will remain diverse and we will not look the same.  \nJust watch an episode of "Red Dwarf."
647648
Diversity means to have a variety and difference, as opposed to being all the same. We can talk about a diversity of cultures, or a diversity of plant and animal life, or even a diversity of religions. It can be used in Biology, Sociology, ethnology or just in plain everyday conversation. We value the word because it helps to create a more interesting planet that is vital and teaming with life. We value diversity in society because it should lead to tolerance and an appreciation of other cultures.
858483
"DIVERSITY INDICES: SIMPSON'S D AND E \nIntroduction: A diversity index is a mathematical measure of species diversity in a community. Diversity indices provide more information about community composition than simply species richness (i.e., the number of species present); they also take the relative abundances of different species into account. Consider two communities of 100 individuals each and composed of 10 different species. One community has 10 individuals of each species; the other has one individual of each of nine species, and 91 individuals of the tenth species. Which community is more diverse? Clearly the first one is, but both communities have the same species richness. By taking relative abundances into account, a diversity index depends not only on species richness but also on the evenness, or equitability, with which individuals are distributed among the different species. \n\nImportance: Diversity indices provide important information about rarity and commonness of species in a community. The ability to quantify diversity in this way is an important tool for biologists trying to understand community structure."\n\nP1(flies) = 20/143\nP2(rats) = 3/143\nP3(cockroaches) = 20/143\nP4(ants) = 100/143\n\nS = 4 (there are only 4 species)\n\nD = 1/(Σ (i = 1 to 4) Pi²)\n= 143²/(20² + 3² + 20² + 100²)\n= 20449/10809\n≈ 1.89\n\nEp = D/Dmax where Dmax = S = 4\nThus Ep ≈ 0.473
631558
Pliny came up with those divisions (or at least described them) in his “Natural History,” written in the First Century A.D.  Science has changed a bit in the last 2,000 years, however, so those divisions no longer accurately reflect the way scientists would describe their fields of study.\n\nFirst off, Pliny himself never intended those categories to include studies such as astronomy or physics (both of which existed in his time, in somewhat different guises).  And there are fields such as chemistry that didn’t exist at all in his time, nor would they confine themselves to those three divisions.\n\nSure, we have biologists, botanists, and geologists, whose jobs might roughly correspond to the “animal, vegetable, and mineral” categories, but we also have microbiologists, paleobotanists, and geophysicists whose jobs would hardly fit into such rigid parameters.\n\nSo the short answer is no, the complexity of modern science defies the categorization of “animal, vegetable, and mineral,” in many more ways than one.\n\n\nRyan Wyatt\nRose Center for Earth & Space\nNew York, New York
20904
One way to look at biodiversity is to view it as the ammount of genetic variation in a population.  The greater the genetic varation is the more likely it is tha an individual in a population will, at random, have the genetic programing capable of overcoming an obstical.  For example, there are some frogs and some are lighter and some are darker and the population spreads into an area where plant cover is darker than the previous habitat. If there is a preadator that cannot see the darker ones because they blend into the plants better, the preadator will remove the lighter ones.  The darker ones will live and reproduce more offspring than the lighter ones.  These offspring  will be darker like thier parents, and in turn produce even more dark offspring.  The lighter ones will produce fewer and fewer each generation because they are getting eaten. If there was no variation in the population and all the frogs were lighter it is likely that the preadator could eat all the frogs and there would be no future generations.
246149
Biodiversity by definition means a variety of life: the different plants, animals and micro-organisms, their genes and the ecosystems of which they are a part.\n\nBiodiversity should be conserved because each species plays a role in its ecosystem. As species become extinct, the equilibrium or balance within the ecosystem is altered. Eventually, these alterations could have a negative impact on human life on this planet. \n\nSee chapter 11 of this online textbook for values of biodiversity: http://www.dbc.uci.edu/~sustain/bio65/Titlpage.htm
518656
Well generalizations/ stereotypes come from some basis of truth but that leads to a mistaken belief that covers 100% of the race that stereotype is attached to.  Even a tribe of people deep in the Amazon could have given type of feature but I'll bet at least a few of them don't fit it completely. Humans are a mixed up bag of personalities aren't they ;-)
117488
Each of the microbes performs a limited number of tasks (so to speak) in maintaining soil structure; some of the tasks are, I suspect, mutually exclusive of others...\n\nIt is actually impossible to be sure why there are so many diverse organisms, beyond that: we weren't there when the structure was put together, and the best we can do besides make this humble observation is make scientific, wild-eyed guesses based on whatever theory we prefer...