Mr. Rojas, a biology teacher, asks his class to evaluate two examples of changes to a pond ecosystem. The table summarizes the examples. Example 1 Example 2 Original pond community algae, cattails, a variety of fishes, ducks, raccoons algae, cattails, a variety of fishes, ducks, raccoons Change to the ecosystem increase in nitrogen and phosphorus content of the water, due to agricultural runoff decrease in the duck population, due to hunting by humans Result after one year an algal bloom that covers the surface of the pond, followed by a decrease in all animal populations Little or no effect; duck population returns to previous levels after one year Based on the results shown in the table, Mr. Rojas's class can evaluate which property of the pond ecosystem? A. the benefits provided by biodiversity within the pond ecosystem B. the ecosystem services that the pond provides C. the climax community that will result from secondary succession D. the resilience of the pond ecosystem to different types of changes

from almost the creation of the first true maps of the earth, people started seeing how continents would be able to fit together.   in particular, people noticed that south america fits almost exactly into africa.

you should be aware that while world maps were around early in the 1600’s and better defined by the end of the 1700’s, those maps were not ‘public’ but were treated as state secrets.   and so it was not till much later that the broader ‘science’ community had access to good quality and accurate world maps.

get the whole story here…

it is now known that most of the major continental masses can be fit together in a jigsaw process.   in fact we now know that the continents were indeed once all joined together as one land mass – the supercontinent of pangaea.

if you look at most world maps you will ponder how this is evidence, as the continents really don’t appear to ‘fit’ together very well.   what you need to understand is that the vast majority of maps are drawn using a map projection that has the north and south poles (which are points) are a line the width of the map at the top and bottom.   this means that the map distorts the true shape of the earth’s land and oceans as you love closer to the poles.     some other map projections distort less, but have the map shape looking like segments of an orange.   see here for a range of map projections.   check out the way greenland changes size in each!

what is more remarkable, is the next piece of evidence when added to the shape of continents.

location of mountains and fossils

what is remarkable, when you reassemble all the continents together, the ancient mountain ranges (many now eroded to their cores) and the location of rock types and fossils all match up.

all matter is made up of atoms

in any element all atoms are the same

elements in a compound are always in a constant ratio: apex