When sudden changes occurs in the body. lack of blood flow in the brain
The whitening toothpastes showed differences in their physical-chemical properties. All toothpastes promoted changes to the surface, probably by the use of a bleaching agent.
Fossils are the preserved remains or traces of animals, plants, and other organisms from the past.
Fossils are important evidence for evolution because they show that life on earth was once different from life found on earth today.
Usually only a portion of an organism is preserved as a fossil, such as body fossils (bones and exoskeletons ), trace fossils (feces and footprints), and chemofossils (biochemical signals).
Paleontologists can determine the age of fossils using methods like radiometric dating and categorize them to determine the evolutionary relationships between organisms.
