Changes

==Negative correlations==

==Negative correlations==

If we can find even one major difference between two samples that cannot be explained by either natural variation or postgenetic transformation, the correlation is considered to be negative and we should conclude that the samples are not genetically related. In some cases, the discrepancy may consist of a single major difference (e.g., presence of an important source-related biomarker in one sample and not in the other). In other cases, the discrepancy may represent the sum of numerous minor differences between the samples. It is crucial in evaluating possible negative correlations that postgenetic effects (e.g., cracking, biodegradation) not be interpreted as genetic characteristics. Moreover, intrinsic differences between immature extracts and mature extracts or oils should not necessarily be interpreted as negative correlations.

If we can find even one major difference between two samples that cannot be explained by either natural variation or postgenetic transformation, the correlation is considered to be negative and we should conclude that the samples are not genetically related. In some cases, the discrepancy may consist of a single major difference (e.g., presence of an important source-related biomarker in one sample and not in the other). In other cases, the discrepancy may represent the sum of numerous minor differences between the samples. It is crucial in evaluating possible negative correlations that postgenetic effects (e.g., cracking, [http://www.oiltracers.com/services/exploration-geochemistry/oil-biodegradation.aspx biodegradation]) not be interpreted as genetic characteristics. Moreover, intrinsic differences between immature extracts and mature extracts or oils should not necessarily be interpreted as negative correlations.

==Positive vs. negative correlations==

==Positive vs. negative correlations==