Final answer:
One way to test the issue of gene versus species trees is by comparing the genetic sequences of different species.
Step-by-step explanation:
One way to test the issue of gene versus species trees is by comparing the genetic sequences of different species. Scientists can use molecular biology techniques, such as polymerase chain reaction (PCR) and DNA sequencing, to analyze and compare the DNA sequences of genes in different species. By doing so, they can determine the similarities and differences in the genetic makeup of these species, which can help in understanding their evolutionary relationships and whether the existing species tree accurately represents their genetic relationships.