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Studying for a test? Prepare with these 8 lessons on Ecology.
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life is everywhere it's hard to find a place on the planet where there isn't life sometimes you might have to look really close but you'll find it one place where you find life where you might not expect it is underneath a couple of miles of ice if you go down to the Antarctic which is one of my favorite places the ice sheets are very thick and basically composed of snow that keeps falling compacting and compacting and compacting until all the air is squeezed out of it you get these enormous sheets of ice because the snow never melts underneath that the pressure is so great that the water that's trapped underneath these ice sheets never becomes completely solid and you'll have this lens a layer of water known as lake vostok that forms below the ice sheet recently a group of Russian geologists built themselves a drilling rig and they drilled down through the ice to sample the water way down and Lake Vostok and guess what they found evidence of what might be a sub ice ecosystem with lots of species of bacteria and maybe even more complex life forms that they don't think came down with the drilling equipment and if this is an extreme enough for you we can go to the other extreme to places where it's really really hot a famous example of that would be in these amazing bubbling boiling cauldrons of water that are welling up from volcanic action in the middle of Yellowstone Park you can do these fantastic tours and you see these amazing colors in all these pools and these colors for the most part are being produced in part by minerals but they're also being produced by life single-celled microbes such as bacteria huge colonies of them we're talking about organisms that can withstand upwards of 80 degrees Celsius which would translate to somewhere in the neighborhood of 180 degrees Fahrenheit so we're getting really close to boiling and that actually prompts the question from some scientist what is the upper temperature tolerance level of life one issue that I think we need to look at here when we talk about life being everywhere is that we're also talking about something called biomass we're talking about the different types of organisms that live in places and the numbers of those organisms combine to give us the weight or mass of those organisms in a given place when I say life is everywhere it's everywhere but it's also really abundant Earth in some ways is a kind of living planet people have said this before but it's really true when you think about in terms of the biomass being distributed everywhere across the earth an important second point is that life is not evenly distributed there are ranges habitats and distributions that are characteristic for each species on earth these are characteristics of any organism that can be studied the ranges can be big or the ranges can be small but every species every type of organism has a specific place or places on earth that it calls home one of my favorite examples of how we need to be careful about what we say or imply about the ranges or distributions of organisms as those cola commercials you see we're polar bears are comforting with penguins the only place where that could happen is in a zoo and I'm pretty sure the zookeepers wouldn't be very happy about it in nature of course polar bears occur in northern latitudes they occur towards the North Pole penguins on the other hand occur only in the southern hemisphere towards the South Pole mostly in the southern regions of the earth so nature of course they never mix because they have different ranges the study of this species distribution phenomenon is something we call bio geography graphy just means writing it down getting it figured out measuring it geo of course means earth bio put the prefix bio in front of all of that and what we're actually studying is where life occurs on the earth and we're describing what those patterns look like and they come to be this brings us back to the concept of species richness that we've mentioned before how many different types of species live in a particular place we want to measure species richness in order to understand some of these biogeography patterns we have different ways of measuring species richness we go out and do surveys and things like that and we find that in some areas we have greater species richness and other areas have many fewer species there will also be variation and how many individuals that are making up each species and what those population sizes are so if you take a drive anywhere just hop in the car and drive anywhere you can see this uneven distribution in the types of organisms and in the number of organisms as you drive by let's start our rather long ish Drive in the Arctic tundra even though it's kind of a desert there you have a complete ecosystem there are different types of organisms that contribute to that ecosystem but the number of species that live in that tundra is kind of low the population sizes may be very high for some of those species but the number of species is actually relatively low except for the tiny microscopic sized organisms you could actually see most of the species that occur in the tundra from the window of your car let's head south and say drive down the Isthmus of Panama and enter the Amazon region you could look out the window of your car and you'd see diversity that's almost too huge to comprehend as you drive by the types and numbers and ranges and distributions of organisms are almost uncountable and we're working on trying to count them but it's a big deal it's a huge challenge for science in the Amazon we're talking about an enormous species richness same thing if you go snorkeling say right here off California it's a fantastic place to go snorkeling there are wonderful organisms lots and lots of them but now think about besides being much more comfortable in the warm of water if you go snorkeling in the Philip instead the diversity and the species richness and even the actual biomass of the organisms that you see in a coral reef in the Philippines is much higher than you'd see along any rocky shore in California and that makes a really great demonstration that not only do you see these differences in patterns on land but you see it in the ocean as well on earth life is everywhere it's just more abundant in some places than in others