No, that’s not Darwinians but the researchers either don’t realize it or –- faced with far-fetched alternative explanations – don’t care:
Choi et al., publishing in PNAS, have proposed a very un-Darwinian account of how “spectacular adaptive radiations” occur on oceanic islands such as Hawaii. This has been a “paradox of evolutionary biology,” they admit. Maybe the diversity is an outworking of “ancient polymorphisms” of ancestors with a rich gene pool —
“Some of the most spectacular adaptive radiations of plants and animals occur on remote oceanic islands, yet such radiations are preceded by founding events that severely limit genetic variation. How genetically depauperate founder populations give rise to the spectacular phenotypic and ecological diversity characteristic of island adaptive radiations is not known. We generated genomic resources for Hawaiian Metrosideros — a hyper-variable adaptive radiation of woody taxa — for insights into the paradox of remote island radiations. We posit that divergent selection and differential sorting of an unexpectedly rich pool of ancestral variation drove the diversification of lineages. Recurring use of ancient variants from a richer-than-expected gene pool may explain how lineages can diversify to fill countless niches on remote islands.”
There’s a hypothesis you may wish to consider. The genetic diversity was already present in the ancestors! Before now, evolutionists have assumed that an organism will have only the genes it needs to survive. If, instead, the ancestors had a “richer-than-expected gene pool” when they entered a new habitat, adaptive radiation amounts to a sorting out of existing information, not the creation of new information by neo-Darwinism’s mutation/selection process.
Evolution News, “Non-Darwinian Adaptive Radiation Proposed” at Evolution News and Science Today (October 26, 2021)
Significance: Some of the most spectacular adaptive radiations of plants and animals occur on remote oceanic islands, yet such radiations are preceded by founding events that severely limit genetic variation. How genetically depauperate founder populations give rise to the spectacular phenotypic and ecological diversity characteristic of island adaptive radiations is not known. We generated genomic resources for Hawaiian Metrosideros––a hyper-variable adaptive radiation of woody taxa—for insights into the paradox of remote island radiations. We posit that divergent selection and differential sorting of an unexpectedly rich pool of ancestral variation drove the diversification of lineages. Recurring use of ancient variants from a richer-than-expected gene pool may explain how lineages can diversify to fill countless niches on remote islands.
Of course, that makes sense and would be a useful subject of research. It’s only disadvantage is that it isn’t Darwinian.
The paper is closed access.