Phenotypic variation, upon which natural selection acts, is central to the adaptive potential of species to diverse environments. Classically, variation was considered to arise slowly through sources such as mutations and reshuffling of standing variation by recombination and migration. This gradualist view of evolution was already questioned by Thomas H. Huxley after reading the manuscript of On the Origin of Species for the first time. In a famous 1859 letter to Charles Darwin he writes:
The only objections that have occurred to me are
1st, That you have loaded yourself with an unnecessary difficulty in adopting Natura non facit saltum (Nature does not make jumps) so unreservedly; and
2nd, It is not clear to me why, if continual physical conditions are of so little moment as you suppose, variation should occur at all.
However, I must read the book two or three times more before I presume to begin picking holes.
Thomas. H. Huxley 23 November 1859
During most of the 20th century, sudden, saltational and large scale changes in phenotypes due to alterations in homeotic genes or modifications in genome organization, such as hybridization or polyploidy were deemed maladaptive and detrimental.
My work focuses on recurrent evolutionary processes which generate or maintain genetic variants with large phenotypic effects and their impact on biodiversity.