The evolutionary story of moths in England during industrialisation reveals that 'evolution is apparently reversible'. Clarify this statement.

(A) In $1850s$,i.e.,before industrialisation,it was observed that there were more white-winged peppered moths $(Biston \ betularia)$ on trees than dark-winged or melanised moths $(Biston \ carbonaria)$.
$\Rightarrow$ However,when the collection was carried out from the same area after industrialisation,i.e.,in $1920$,there were more dark-winged moths in the same area,i.e.,the proportion was reversed.
Before industrialisation,thick growth of white-coloured lichen covered the trees. In that background,the white-winged moth survived,but the dark-coloured moths were picked out by predators.
$\Rightarrow$ Lichens can be used as industrial pollution indicators.
$\Rightarrow$ They do not grow in areas that are polluted.
$\Rightarrow$ During the post-industrialisation period,the tree trunks became dark due to industrial smoke and soot.
$\Rightarrow$ Under this condition,the white-winged moth did not survive due to predators,while dark-winged or melanised moths survived.
$\Rightarrow$ Hence,moths that were able to camouflage themselves,i.e.,hide in the background,survived.
$\Rightarrow$ This understanding is supported by the fact that in areas where industrialisation did not occur,e.g.,in rural areas,the count of melanic moths was low.
$\Rightarrow$ This showed that in a mixed population,those that can better adapt,survive and increase in population size.