Answer: B speciation causing an increase or decrease in competition among different species.
The other choices are the HIPPCO or the human impacts that cause extinction not geographical changes
Probably. Ecosystems are connected. While scientists do break the world
down to study it in smaller pieces because we can't comprehend the
ecosystem of the whole world at one time, the whole world is one big
ecosystem. Some parts of it are more directly connected to others, and
some parts are less directly connected. If something catastrophic
happened in one ecosystem, it would affect other ecosystems. But also
remember that the bigger the network, the less any one species affects
it. Because<span> there
are so many species in the world, the world is a HUGE ecosystem. The
affect would be somewhat absorbed by the vastness of the ecosystem.
However, if the extinction of one species (such as fish) has a large
impact on one ecosystem, it's impact on surrounding ecosystems might be
noticed. When you look at the world as a whole, it's not the extinction
of any one species that is very, very dangerous but the extinction of
many species. If enough species (like the fish) died in "separate"
ecosystems, eventually the ecosystem of the whole would be affected.</span>
A Group Of People That Work Together. They Depend On Each Other And Help Each Other Out.
Well you see dinosaurs are hypothesized to be extinct because one, the atmosphere today won't really let most animals become as big as long ago, two these things were giant cold blooded lizards they had some unknown properties and they were different than what we have today. We don't know much about dinosaurs. The theory of an asteroid destroying all dinosaurs is supported by many facts it is still unknown. The fact that we don't see the lizards around, and in only in myths is enough for one species to be hypothesized extinct.
The rapid evolution of the human immune system creates the potential for human-specific disease. As a result, human-specific variation in many other human immune genes influences human-specific disease risks.