Well, Science has pretty much destroyed any concept of simple life evolving into complex due to the massive amount of data from DNA.
There are over 2,755,000 peer articles on PubMed.com alone, showing only genetic losses and diseases.
Medical research has yielded a mass of huge numbers of research data that destroys any possibility of any form of improvement is possible. There are over 100,000 deleterious, germline, mutations found and NO positive mutations.
Positive germline mutation is that it must increase complexity NOT be associated with any disease, not be part of normal immune responses to pathogens and/or any of the following: 1/ add new genes with new functions 2/ increase health and fitness to survive 3/ increase intelligence.
Positive mutations are easily shown to be what any sane person would expect to see if evolution were true.