<span>hello there hester , i would say needed to form cell membranes</span>
        
             
        
        
        
Well, scientists depend on science.They use the process of observation. But there are processes for these. The processes are;
Asking a question; Scientists wonder how specific happenings can be explained, they look for an answer.
They perform research; the scientists study the  particular thing, and look for reasons for a particular happening.
They form a hypothesis; a hypothesis is a statement which is not universally true, they are observations that haven't been agreed upon.
They test their hypothesis; they perform experiments to find out if their hypothesis is true.
They analyse the data and draw a conclusion; they record their hypothesis and write down their end result.
They pass across their result; they pass their new observation across to other people.
    Hope i helped. Have a nice day. 
        
                    
             
        
        
        
Answer:
Evolution reflects the adaptations of organisms to their changing environments and can result in altered genes, novel traits, and new species. Evolutionary processes depend on both changes in genetic variability and changes in allele frequencies over time.
 
        
             
        
        
        
The lining of the heart is the pericardium.
        
                    
             
        
        
        
Answer:Amphibians evolved during the middle of the Devonian period (416 to 359 million years ago) from the lobe-finned fish of the vertebrate class Sarcopterygii. Species within the genus Ichthyostega (members of the Labyrinthodontia subclass) are considered by some scientists to be the earliest amphibians.
Explanation: