[gene: a hereditary unit] Individuals are selected. Evolution can be divided into microevolution and macroevolution.
The kind of evolution documented above is microevolution.
One common mistake is believing that species can be arranged on an evolutionary ladder from bacteria through "lower" animals, to "higher" animals and, finally, up to man.
Mistakes permeate popular science expositions of evolutionary biology.
The increase in relative abundance of the dark type was due to natural selection.
The late eighteen hundreds was the time of England's industrial revolution.
The greater number of offspring left by dark moths is what caused their increase in frequency. A single organism is never typical of an entire population unless there is no variation within that population. It unites all the fields of biology under one theoretical umbrella.It is not a difficult concept, but very few people -- the majority of biologists included -- have a satisfactory grasp of it.Individual organisms do not evolve, they retain the same genes throughout their life.When a population is evolving, the ratio of different genetic types is changing -- each individual organism within a population does not change.