"ultimate hypothesis" is correct and can be used in written English.
It refers to the final or most important hypothesis in a series of hypotheses. Example: After conducting numerous experiments and analyzing the data, the researchers came up with their ultimate hypothesis - the key to curing cancer lies in targeting specific genetic mutations in cancer cells.
These fine-grain immunocytochemical data appear to have an immense predictive power for physiological and pharmacological studies and continue to serve as the ultimate test of hypotheses drawn from functional studies.
Future investigation of the proposed mechanisms will provide the ultimate test of our hypothesis that lesions of the suprachiasmatic nucleus play an important role in the etiology of schizophrenia.
However, the ultimate test of this hypothesis requires establishing the sex determination system for additional species and correlating these data with the hybrid cross dataset.
The ultimate proof for this hypothesis would be that intervening in the cascade would prevent neuronal loss and cognitive deterioration.
While the ultimate evaluation of this hypothesis will require the completion of large-scale sequencing studies, it is informative to place it in the broader context of what is known about the genetic architecture of complex disease.
It also reviewed epidemiological literature available in 2005, and concluded that long-term clinical study would be required to provide the ultimate support to the hypothesis that blue light-filtering IOLs might provide retinal photoprotection against the development or progression of AMD.
Using the hypotheses for ultimate strength design sanctioned by ACI 318-05 (2008), the minimum total reinforcement area required to provide adequate resistance to axial load and moment is shown to occur for particular constraints on longitudinal reinforcement area or distributions of strain.
Atkins's diet is both the ultimate manifestation of the alternative hypothesis as well as the battleground on which the fat-versus-carbohydrates controversy is likely to be fought scientifically over the next few years.
The results confirm, from a quantitative perspective, our main hypothesis that some ultimate geographical endowments and socioeconomic or political drivers have determined land cover changes which, in turn, have altered both structural and functional landscape properties.
