Microevolution, on the other hand, refers to smaller evolutionary changes "within" species or populations. During microevolution changes in allele frequencies definitely do occur. Some biologists, Richard Dawkins in particular, have suggested that the gene is the object of selection. This was always challenged by Ernst Mayr "The individual is the entity which survives or not, which reproduces or not, and which reproduces successfully or not". Changes in gene frequency in populations is a by-product of what happens to individuals.