Convergent evolution- losing the eye
This is not Lamarkian
A recent study from biologists at New York University 
about evolution of cave adaptations in cave fish suggests that the loss of eyes and pigmentation has occurred frequently and repeatedly as new populations of surface living fish with eyes migrated into and lived in caves. The DNA research shows that this is an example of convergent evolution where different populations or species evolve similar traits independently.
Some people might see this example as evidence for Lamarkian inheritance. Following this "logic", the population of eyed fish that moved into the caves would not need to have eyes or pigmentation in the dark so their offspring would be born without eyes or pigmentation. This argument is falacious in that acquired traits are not inherited. The idea of "need" is not valid in evolution. There is no need to lose eyes even if the organ is not useful in the dark caves. Teachers can emphasise the fact that those organisms that have the mutation not to produce the eye or a pigment can survive and reproduce offspring with their mutation. These mutants may even have an advantage over those fish with eyes in that, the energy needed to make the eye and keep it working can be used for survival in the nutrient poor environments of caves.
This example could be used in Option D Species & Speciation