@ Dr. Heinz Lycklama
Kettlewell’s Experiments
nIn the early 1950’s Bernard Kettlewell
performed some experiments that suggested that predatory birds ate light-colored moths when they became more
visible on pollution-darkened
tree trunks
nIt appeared that natural selection played a
role in the survival of the dark-colored variety of moths
nMost biology textbooks illustrate this
example of “natural selection” with
photographs showing two varieties of peppered moth resting on light- and dark-colored tree trunks
nWhat the textbooks do NOT tell you is that these photographs have been staged since peppered
moths in the wild do
not rest on tree trunks