Answer:
during the Cambrian Period of the Paleozoic Era.
Explanation:
The Paleozoic is the earliest era (of three) of the Phanerozoic Eon and is composed of six geologic periods: the Cambrian, Ordovician, Silurian, Devonian, Carboniferous, and Permian (in that order from earliest to the latest). Fish first appeared about 530 million years ago during the Cambrian explosion.
B! The strongest characteristics will survive when the weak ones won't
Answer:
Deforestation is the major problem causing lack of rich species in Costa Rica. This is due to over grazing by cattle.This may lead to flooding which affect fertility of the soil.These animals graze on the plants without regulations,and cause erosion as their hoofs percolate the soil, further reducing soil fertility.
In addition to sustain the beef production, trees were fell to for cattle ranching.This ultimately contributed to loss of the forest species.
Banana plantation is an additional factor.Forest were cleared to cultivate banana, which affects forest population.
Explanation:
A seismometer is used to measure the motion in the ground caused by earthquakes, volcanoes, or explosives.
