Defense System Evolution

The defense system that protects all complex life on Earth, including humans, can be traced back to ancient microbes known as Asgard archaea. This discovery sheds light on the origins of the immune mechanisms that have been essential in defending life from viral threats for billions of years. Around 2 billion years ago, the ancestors of plants, animals, and fungi emerged, likely evolving from a group of complex microbes called Asgard archaea. These primitive organisms passed down two crucial defense