Answer:
Because they happen naturally.
Explanation:
climate changes are natural to our planet and happen over time, according to the factors that act on the planet. In this way, climate changes should not be a concern for us, the problem is the speed with which they are happening.
Human activities use a lot of fossil fuels that stick to the atmosphere and accelerate these changes, which cause serious problems in the life of the planet.
Answer:
The Gold Rush was the largest mass migration in U.S. history. In March 1848, there were roughly 157,000 people in the California territory; 150,000 Native Americans, 6,500 of Spanish or Mexican descent known as Californios and fewer than 800 non-native Americans
Answer:
The animals have more adaptability to new environments today than in years past
Explanation:
The fossil range can simply be defined as the time period in which an organism has existed, thus left fossil traces of its existence. The fossil range can be very short, medium, or long, thus usually there are limitations before certain type of organism evolves into another species, thus eliminating the ancestral organism from the fossil records. On the other hand, there are organisms that have incredibly big fossil ranges of several hundred million years, and since they emerged, they have remained almost unchanged. Those kind of fossil ranges are very rare though, and they don't represent the general picture. Most of the fossil ranges are between several thousand years and several million years, as that is usually how much a species exists, ending its reign, be it because of competition, changes in the environment, or big natural disaster.
