EVIDENCES OF EVOLUTION

• Evolution is the global change in a population's genetic and physical traits.
• Evolution can only be observed after a long period of time.
• Evolution is the reason why organisms come in different shapes and sizes.
• Evidences of Evolution:

  1. Fossil records
  2. Comparative anatomy
  3. Embryonic development
  4. Genetic information
• Fossils are remnants or remains of ancient organisms. They give us a picture of how organisms have changed over time.
• Scientists consider the fossil's age, the place where it was found, and the type of environment the organism lived in.
• Some types of fossils can be found in the layers sedimentary rocks, while the others are trapped in amber.
• Paleontologist make initial estimates of the age through the position in the sedimentary rocks. Fossils found in the bottom layer are much older than those found in the upper layer of rocks.
• Both biologists and geologists date the history of the Earth with the help of the Geologic Time Scale (GTS).
• GTS organizes the history of the Earth, noting the major changes or events that have occurred.
• GTS uses evidence from fossil and geologic records to identify the organisms that existed during a particular time in the past and how the Earth and its climate were like.
• Using the GTS, scientists have estimated that the Earth is about 4.5 billion years old, divided into a series of units based on the order in which different groups of rocks and fossils were formed namely: Eon, Era, Period, and Epochs.

  Era is the largest division of the GST namely: Precambrian, Paleozoic, Mesozoic, and Cenozoic.