Ellen White describes Morgan's work as failing to be empirical, not addressing evidence that contradicts the hypothesis, relying on comparative anatomy rather than selection pressure, not predicting any new evidence and failing to address its own shortcomings. White stated that while the hypothesis had the scientific characteristics of explanatory power and public debate, the only reason it has received any actual scholarly attention is due to its public appeal, ultimately concluding the AAH was unscientific.[62] Others have similarly noted the AAH "is more an exercise in comparative anatomy than a theory supported by data."[5]
Though describing the hypothesis as plausible, Henry Gee went on to criticize it for being untestable, as most of the evolutionary adaptations described by Morgan would not have fossilized. Gee also stated that, while purely aquatic mammals such as whales show strong skeletal evidence of adaptation to water, humans and human fossils lack such adaptations (a comment made by others as well[24]); that there are many hypothetical and equally plausible scenarios explaining the unique characteristics of human adaptation without involving an aquatic phase of evolution; and that proponents are basing arguments about past adaptations on present physiology, when humans are not significantly aquatic.[63] There is ultimately only circumstantial evidence to suggest, and no solid evidence to support the AAH.[64][65] ScienceBlogs author Greg Laden has described the AAH as a "human evolution theory of everything" that attempts to explain all anatomical and physiological features of humans and is correct in some areas only by chance. Laden also states that the AAH was proposed when knowledge of human evolutionary history was unclear, while more recent research has found that many human traits have emerged at different times over millions of years, rather than simultaneously due to a single evolutionary pressure.[34]
Evolutionary biologist Carsten Niemitz states that he believes the AAH as expressed by Morgan did not fulfill the criteria of a theory or a hypothesis, merely "[listing] analogies of features of savannah type mammals on the one hand and of aquatic mammals and man on the other, asking the scientific community for explanations other than a common aquatic ancestor of extant man."[16]