Why Bacteria are considered as most primitive organism?
Answers
Heya Mate...
The current "Procaryotic dogma" claims that procaryotes are primitive. Since the ancestor of Archaea wasmost probably a hyperthermophile, and since bacteria too might have originated from hyperthermophiles, the procaryotic dogma has been recently connected to the hot origin of life hypothesis...
It may Help you...
Follow me...
#Raghav Pandey
Answer:
Since they can adapt to widest range of atmospheric conditions, so it is believed that when many of the animals would have gone extinct due to harsh atmospheric conditions they still had survived. They are believed to be on Earth back in the time when even Humans were not present on Earth. Because of their of adaptation abilities they are still present, while a great number of animals got extinct in the mean time.