● Another `color{Violet}"interesting observation"` supporting evolution by natural selection comes from `color{Violet}"England"`.
● In a `color{Violet}"collection of moths"` made in `color{Brown}"1850s"`, i.e., `color{Violet}"before industrialisation"` set in, it was observed that there were more `color{Violet}"white-winged moths"` on trees than dark-winged or melanised moths.
● However, in the collection carried out from the same area, but `color{Violet}"after industrialisation"`, i.e., in `color{Brown}"1920"`, there were more `color{Violet}"dark-winged moths"` in the same area, i.e., the proportion was reversed.
● The explanation put forth for this observation was that `color{Brown}"predators will spot"` `color{Brown}"a moth against"` `color{Brown}"a contrasting background"`
● During `color{Violet}"post industrialisation period"`, the tree trunks became dark due to `color{Violet}"industrial smoke"` and `color{Violet}"soots"`.
● Under this condition the `color{Violet}"white-winged moth"` did not survive due to `color{Violet}"predators"`, dark-winged or melanised moth survived.
● `color{Violet}"Before industrialisation"` set in, thick growth of almost `color{Violet}"white-coloured lichen"` covered the trees - in that background the white winged moth survived but the dark-coloured moth were picked out by predators.
● `color{Brown}"NOTE"`: `color{Violet}"Lichens"` can be used as `color{Violet}"industrial pollution indicators"`. They will `color{Violet}"not grow"` in areas that are polluted.
● Hence, moths that were able to `color{Violet}"camouflage themselves"`, i.e., hide in the background, survived.
● This understanding is supported by the fact that in areas where `color{Violet}"industrialisation did not occur"` e.g., in rural areas, the count of `color{Violet}"melanic moths was low"`.
● This showed that in a `color{Violet}"mixed population"`, those that can `color{Violet}"better-adapt"`, survive and `color{Violet}"increase in population"` size.
● Remember that no variant is `color{Violet}"completely wiped out"`.
● Similarly, `color{Violet}"excess use"` of herbicides, pesticides, etc., has only resulted in `color{Violet}"selection of resistant varieties"` in a much lesser time scale.
● This is also true for `color{Violet}"microbes"` against which we employ `color{Violet}"antibiotics"` or drugs against `color{Violet}"eukaryotic organisms/cell"`.
● Hence, `color{Violet}"resistant organisms"`/cells are appearing in a time scale of `color{Violet}"months or years"` and not centuries.
● These are examples of `color{Brown}"evolution by"` `color{Brown}"anthropogenic action"`.
● This also tells us that evolution is `color{Violet}"not a direct process"` in the `color{Violet}"sense of determinism"`.
● It is a `color{Violet}"stochastic process"` based on `color{Violet}"chance events"` in nature and chance mutation in the organisms
● Another `color{Violet}"interesting observation"` supporting evolution by natural selection comes from `color{Violet}"England"`.
● In a `color{Violet}"collection of moths"` made in `color{Brown}"1850s"`, i.e., `color{Violet}"before industrialisation"` set in, it was observed that there were more `color{Violet}"white-winged moths"` on trees than dark-winged or melanised moths.
● However, in the collection carried out from the same area, but `color{Violet}"after industrialisation"`, i.e., in `color{Brown}"1920"`, there were more `color{Violet}"dark-winged moths"` in the same area, i.e., the proportion was reversed.
● The explanation put forth for this observation was that `color{Brown}"predators will spot"` `color{Brown}"a moth against"` `color{Brown}"a contrasting background"`
● During `color{Violet}"post industrialisation period"`, the tree trunks became dark due to `color{Violet}"industrial smoke"` and `color{Violet}"soots"`.
● Under this condition the `color{Violet}"white-winged moth"` did not survive due to `color{Violet}"predators"`, dark-winged or melanised moth survived.
● `color{Violet}"Before industrialisation"` set in, thick growth of almost `color{Violet}"white-coloured lichen"` covered the trees - in that background the white winged moth survived but the dark-coloured moth were picked out by predators.
● `color{Brown}"NOTE"`: `color{Violet}"Lichens"` can be used as `color{Violet}"industrial pollution indicators"`. They will `color{Violet}"not grow"` in areas that are polluted.
● Hence, moths that were able to `color{Violet}"camouflage themselves"`, i.e., hide in the background, survived.
● This understanding is supported by the fact that in areas where `color{Violet}"industrialisation did not occur"` e.g., in rural areas, the count of `color{Violet}"melanic moths was low"`.
● This showed that in a `color{Violet}"mixed population"`, those that can `color{Violet}"better-adapt"`, survive and `color{Violet}"increase in population"` size.
● Remember that no variant is `color{Violet}"completely wiped out"`.
● Similarly, `color{Violet}"excess use"` of herbicides, pesticides, etc., has only resulted in `color{Violet}"selection of resistant varieties"` in a much lesser time scale.
● This is also true for `color{Violet}"microbes"` against which we employ `color{Violet}"antibiotics"` or drugs against `color{Violet}"eukaryotic organisms/cell"`.
● Hence, `color{Violet}"resistant organisms"`/cells are appearing in a time scale of `color{Violet}"months or years"` and not centuries.
● These are examples of `color{Brown}"evolution by"` `color{Brown}"anthropogenic action"`.
● This also tells us that evolution is `color{Violet}"not a direct process"` in the `color{Violet}"sense of determinism"`.
● It is a `color{Violet}"stochastic process"` based on `color{Violet}"chance events"` in nature and chance mutation in the organisms