 Thus, by the spring of 1837, Darwin had changed from supporting the idea that each species was independently created to supporting the notion that each species was descended from another species - the switch from teleological to transmutationist views.In relation to the struggle for existence, Darwin explains in "Origin of Species "that "forms that are successful in the struggle for existence are deemed to be slightly better adapted than those with which they have had to compete for their places in the economy of nature".Supporting this claim, in about 1855, Darwin noted that the struggle for existence would produce diversification – leading to Darwin’s principle of divergence.