The probability of finding ultra-conserved elements by chance (under neutral evolution) has been estimated at less than 10 in 2.9 billion bases.
The methods used to identify adaptive evolution are generally devised to test the null hypothesis of neutral evolution, which, if rejected, provides evidence of adaptive evolution.
Assuming neutral evolution, without any selective pressure, the expectation would be that only one of the 5,014 bacterial genes would have more than one mutation.
Under neutral evolution, genetic recombination will result in the reshuffling of the different alleles within a haplotype, and no single haplotype will dominate the population.
This thinking leads to an evolutionary proposal called "constructive neutral evolution" in which the order of steps is reversed, with the gratuitous capacity for editing preceding the "defect".
"A test of neutral molecular evolution based on nucleotide data".
This marked the beginning of the controversy over neutral evolution and the "neutralist-selectionist debate", primarily between organismal and molecular biologists, which would continue throughout King's career.
Maximum likelihood has been criticised as assuming neutral evolution implicitly in its adoption of a stochastic model of evolution.
Because they segregate together, non-neutral mutations linked to neutral polymorphisms result in decreased levels of genetic variation relative to predictions of neutral evolution.
As James Crow put it, "much of Kimura's early work turned out to be pre-adapted for use in the quantitative study of neutral evolution".