<span>Metamorphic rocks form by existing rocks join together under high heat and pressure. Examples of metamorphic rocks are marble, schist, slate, and quartzite. Metamorphic rocks formed when the minerals are chemically changed due to heat and pressure. They are often seen near magma but they do not melt like igneous rock.</span>
Darwin's "Origin of Species" and Lamark's "Theory of Inherited Characteristics"
Positive feedback is a control system that sends a signal to ( increase) a response.