If by “adaptations” they mean “mutations,” then logically they must always be random regardless of the needs of the creature. Just because you’re out at sea all the time, doesn’t mean your kids are going to develop gills.
The restatement of Darwinian Natural Selection adds “mutations arise at random” to the environmental (and sexual) selection process — but basically, only the random mutations lead to speciation; there’s no role that the ns hypothesis *can* play in speciation, it can only work as a method of extinction.
Add in the documented facts of mass extinction events caused by (for example) big rocks from space, and it’s easy to see why the Chicxulub impact and the Alvarez model is still being attacked by the “my state-paid professor said it, I believe it, that settles it” students ‘educated’ in the UK.
The relatively recent development of fair skinned homo sapiens living in Europe, and lactose digesting (milk consumption) enzymes in central Europe are prime examples. These mutations undoubtedly popped up occasionally long before they became useful to their owners. It was not until former Africans moved into Europe that they needed light skin to better use sun on the skin to produce vitamin D essential for good hip (reproductive) structure. Also, until homo sapiens began herding and milking cattle, there was no special utility to having lactose digesting enzymes. Once they had survival value, these genes proliferated rapidly by enhancing survival.