Traditionally, the battle has been between Creationism (in its highest form - Intelligent Design) and Darwinism (in its highest form - Evolution). Increasingly, people realize that both Creationism and Darwinism in their most basic form, are oversimplified; yet simultaneously there is undeniable and ever growing mountain of evidence for both Intelligent Design and Evolution.
Therefore, enter the new kid on the block, Interventionism. In this scenario, one that is rapidly gaining supporters due to its logical coherence and ability to satisfactorily take into consideration undeniable evidence on both Intelligent Design and Evolution, and backed by (when seen in the possibility of the Interventionism context) scientific and genetic evidence, the conclusion is inevitable - Extraterrestrials were involved in the Intelligent Design of many species of organisms (including Homo sapiens sapiens), and it is more than likely that (many) more than one group of extraterrestrials were involved, at different time periods for different agendas, and by logical extension, most extraterestrials have themselves been genetically 'Intervened' by yet other extraterrestrials at some point in their evolutionary lineage.
And of course, all beings in the universe are continually in an ongoing, never-ending process of Evolution - the purpose of life. One might then say, Intelligent Design and Interventionism, are not by nature against the grain of Evolution, but are indeed *part* of the greater scheme of Evolution.
In the following article, published in the scientific magainze Nexus, the author, a specialist in the scientific field of Interventionsim, briefly explains the theory, and summarizes the evidence, for Interventionsim.
Interventionism > Creationism + Darwinism