Answer:
share a common ancestor
Explanation:
<em>The similarity in their embryos and embryonic development suggests that reptiles, birds, and mammals share the same ancestor.</em>
Similarity in the structure and development of embryo is one of the evidences that is been used by scientists to support the theory of evolution of species. According to the theory of organic evolution, all organisms are on earth as a result of descent with modifications from common ancestors. 
<u>Reptiles, birds, and mammals are all vertebrates. They share some basic characteristics and are thought to have shared a common ancestor before each group took different adaptive channels leading to their  differences as they currently exist.</u>
 
        
             
        
        
        
Gravitational attraction between two celestial objects (i think)
        
             
        
        
        
D because carbon, nitrogen, and oxygen are apart of like everything
        
             
        
        
        
Answer:
D. determine the probability of traits
 
        
             
        
        
        
Answer: The role of an organism in the ecosystem is called its NICHE.
Explanation: The niche (pronounced 'neesh') of an organism is the specific function and purpose of the organism within its environment, ecosystem or food-web or food-chain.