Answer:
c
Explanation:
it weakens an ecosystem.biodiversity is the slight changes of one organisim to the next inside a species. when a species looses biodiversity, the traits that the one organisim had are gone and none of the others can adapt this trait. adaptation is what keeps speicies alive. thus, loss of biodiversity is bad and weakens an ecosystem.
I think it is 10% ......................
Clues such as fossils such as bones, footprints, tar, etc, preserved underground helped inform scientists. You can also count how old a tree is when you cut it open and there are some alive for thousands of years so that is a possible way.
In the enviroment isolated , animals have the time to "adapt" t their surroundings.
The flower mechanism that would not help them preventing pollination by a specie such as a foreign plant would be that the flowers of different species are then the same color and would attract the same pollinators.Hope this would be of help.