Sentences with phrase «little direct evidence»

But little direct evidence exists to prove which tree species filled the forests before they were cleared for fields and fuel.

Many researchers agree that shifts in climate and environment shaped human evolution, but there has been little direct evidence about exactly how.

But little direct evidence of Hadean asteroid impacts still exists, limiting scientists» understanding of how those collisions affected the planet's habitability.

Because of the unprecedented nature of the world Ebola epidemic, so far there is little direct evidence on the anesthetic management of EVD.

«Several studies and clinical evidence suggest AIM2 functions as a tumor suppressor, but until now, we've had very little direct evidence to explains how this occurs,» said Justin E. Wilson, PhD, the study's first author and a postdoctoral fellow at UNC Lineberger, the UNC School of Medicine Department of Microbiology and Immunology and the Department of Genetics.

But until his study, «there was little direct evidence for the magnitude of the problem in China».

«At present, there is little direct evidence demonstrating that electronic alcohol screening and brief counseling intervention has a meaningful population - level effect on excessive alcohol consumption or related harms in any group, and therefore its utility as a stand - alone public health approach is in doubt.

Optimism, not confidence, because there is little direct evidence bearing on the question.

Until now, scientists had little direct evidence of the Great Barrier Reef's age and evolution, but data from seismic profiles and drilling projects nearby suggested it might not have formed until as recently as 500,000 years ago.

«As the story goes with exercise - induced changes in strength, neural adaptations are contributing first with muscle growth playing a more prominent role in the latter portion of a training program: however, there is little direct evidence that this is actually true in an adult partaking in a resistance training program,» said Dr. Jeremy Loenneke, senior author of the Muscle & Nerve article.

But there was little direct evidence to support the theories, so Santana decided to study a large number of monkey species, in a wide variety of social group sizes and environments, to see how their faces had evolved.

Researchers at that time simply had little direct evidence to offer.