What happened during the "Cambrian explosion" Mammals began to dominate the Earth

A large explosion occurred on the surface of the Earth, ending the Cambrian era and beginning the next.

An asteroid caused a mass extinction

This is when there was a major increase in the number and diversity of invertebrate species in a short period of time,​

For the strategies below, decide whether they are best described as demand-side solutions or supply-side solutions to meeting human needs for fresh water. remember that a demand-side solution reduces demand for fresh water, whereas a supply-side solution increases the supply of fresh water. (a) damming a river to create a reservoir (b) desalinating seawater (c) a nation invading a neighboring country to access their rivers (d) raising water prices for consumers and businesses (e) providing tax breaks for companies that use less water (f) replacing inefficient irrigation with more-efficient drip irrigation to grow crops (g) requiring low-flow showerheads in all new homes