Answer:
d. the groups will probably diverge genetically, and speciation may occur
Step-by-step explanation:
The geographical isolation of two populations of a species for a longer time period leads to allopatric speciation. During the process, the isolated populations accumulate genetic variations to become adapted to the prevailing conditions of the habitat.
Accumulation of genetic variations leads to reproductive isolation between the population. After several generations, the individuals of the two isolated populations are unable to interbreed due to genetic variations. Now, these two populations are said to belong to two different species. The isolated lizard populations would also accumulate genetic variations resulting in allopatric speciation.