The phrase "changes may have occurred" is correct and usable in written English.
You can use this phrase when you want to express the possibility that something has been altered or shifted. For example: "Given the amount of time that has passed since we last spoke, changes may have occurred in our young professional network."
The suspected changes may have occurred over many thousands of years.
Whatever mental changes may have occurred, she was still physically the same person as the participant in the Moors murders.
However historic distributions can be difficult to estimate objectively because substantial habitat changes may have occurred prior to comprehensive surveys.
Because restaurants are ever-evolving, however, changes may have occurred in menus, chefs and management since the date of the review.
These changes may have occurred to accommodate cognitive functions that are specific to humans, so further work using this new method may provide a better understanding of how human cognitive abilities emerged.
Using birth records from 1990-2001 andatata from the 1990 and 2000 Censuses, this paper documents changes in the spatial distribution of poor infant health within metropolitan areas with large African-American populations, and explores why these changes may have occurred.
The incidence of this tumour may have increased in recent years, but this change may have occurred because of changing patterns of diagnosis or because of the difficulty of separating adenocarcinomas in the gastric cardia from those in the oesophagus (Kubo and Corley, 2002).
The change may have occurred much more quickly, and researchers plan to refine their oxygen timetable by analyzing more rock samples.
It's also important to keep in mind that substantial amounts of evolutionary change may have occurred in a lineage after it diverged from other closely related lineages.
Drugstore brand items started appearing in amenity bags in the mid-1980s, buthehe most transforming change may have occurred in 2000, when Ms. Gittelson persuaded Delta Air Lines to take a chance on Essentiel Elements, an aromatherapy company in California that at the time was little known outside of a few department stores and spas.
After a longer duration of yoga practice a greater magnitude of change may have occurred.
