The answer is immune system
Explanation:
Evolution is a slow natural process occurring in living organisms which explains the formation of the diversity of organisms on Earth. In simple terms, evolution explains how life survived on Earth after the origin of life but it cannot explain the origin of life. However, modern evolutionary biologists are now trying to decode the origin of life through evolutionary evidence and support that earlier form of life originated in the large oceans around 3.5 billion years ago. These organisms are simple living unicellular organisms which later evolved into the eukaryotic organisms.
Answer:
Open circulatory system:
Relies on the heart to keep blood flowing
Used in all vertebrates
Sorry thats all i know :)
