sodium amytal test: anesthetize one hemisphere and check for language function dichotic listening test: report more digits heard by dominant half functional brain imaging: fMRI or PET used to see which half is active when performing a language test
The process of change by which new species develop from preexisting species over time? The process by which species change over time is evolution. The process by which new species develop from preexisting species over time is evolution.
One way species change over time is called convergent evolution. Convergent evolution is when two species, that are not related via a recent common ancestor, become more similar. Most of the time, the reason behind convergent evolution occurring is the build up of adaptations over time to fill a certain niche. When the same or similar niches are available in different geographical locations, different species will most likely fill that niche.