These fossils are very useful for us because we can use them to date the layers of rock that they are found in. Fossils that can be used in this way are called index fossils, and rock layers with the same index fossils in them can be correlated. Not my answer, link here for full
http://peter-mulroy.squarespace.com/correlating-rock-layers/
Sudden fever, headache, stiff neck. Additional symptoms may include nausea, vomiting, sensitivity of the eyes to light, confusion, and rashes (typically dark purple spots on the torso, arms or legs).
Growing, Obtaining Energy, realsing energy, releasing waste,reproduction, reacting to surroundings
<h3>Natural selection:-</h3>
Natural selection is the process through which populations of living organisms adapt and change. Individuals in a population are naturally variable, meaning that they are all different in some ways.This variation means that some individuals have traits better suited to the environment than others.
<h3>Evolution occur in natural selection:-</h3>
Through this process of natural selection, favorable traits are transmitted through generations. Natural selection can lead to speciation, where one species gives rise to a new and distinctly different species. It is one of the processes that drives evolution and helps to explain the diversity of life on Earth.
<h3>hope it will help u in understanding..</h3>
