Keep in mind that they were brought about by evolutionary processes that operated not merely at some time in the distant past, but which continue to operate in the present and can be expected to give rise to new forms in the future. Jaguar I t is also important to realize that most species are genetically diverse. To do so, however, is to ignore the reality of variation in nature. A nother problem in classifying a newly discovered organism is in determining the specific characteristics that actually distinguish it from all other types of organisms. There is always a lively debate among researchers over defining new species because it is not obvious what are the most important traits.
T here are two schools of thought.
The first defines new species based on minor differences between organisms. The second tends to ignore minor differences and to emphasize major similarities. However, such breeding experiments are rarely undertaken because of practical difficulties. When defining species from the fossil record, for instance, it is not possible to go back in time to observe breeding patterns and results. Therefore, we are left with morphological characteristics as the criteria for identifying species differences.