30 POINTS!! After 70 years of absence, the gray wolf was reintroduced to Yellowstone National Park in 1995. After 1995, the elk population, which had been exploding, began to decline in numbers. Willows and aspen trees began to grow more abundantly on riverbanks. The beaver population began to increase, and songbirds were more abundant in the grasslands and riverbanks. What is the MOST LIKELY explanation for these events after the wolf was reintroduced?
A
The wolves began preying on the elk, and the beaver started using the trees to make lodges.

B
After the gray wolves came back to Yellowstone, the carrying capacity of the ecosystem increased.

C
The wolves' reintroduction altered the limiting factors for the elk, the beavers, the trees, and the songbirds.

D
The wolf's presence caused a decrease in the elk population, which allowed the riverside trees to grow more abundantly, which provided logs for the beavers' lodges and habitats for the songbirds.

The most likely explanation would be that the presence of wolves caused a decrease in the elk population, which allowed the riverside trees to grow more abundantly, which provided logs for the beavers' lodges and habitats for the songbirds.

The wolves introduced to the ecosystem must have been preying on the elk population, leading to a reduction in their population size.

Reduction in the population size of elk means that less predation on riverside trees, making them grow more abundantly.

The thriving of riverside trees provides logs for beavers' lodges and nest-building habitats for songbirds.

More species interaction in the ecosystem can be found here:

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.

when a reversible reaction is occurring in both directions at the same rate; the products and reactants do not change in concentration. a chemical reaction where the compound is broken into its constituent parts.