Casa ESL · C2 Mastery · Unit 6 of 20 · Step 1
Scientific hedging at the highest level — tentative conclusions, limitations
Name
Date
Vocabulary
phenotype
nounThe set of observable characteristics of an organism resulting from the interaction of genotype and environment.
"The phenotype is not determined by genetics alone but by a complex interplay of factors."
vestigial
adjectiveForming a very small remnant of something that was once much larger or more noticeable.
"The human appendix is often cited as a vestigial organ, though its function may be more complex than previously assumed."
speciation
nounThe formation of new and distinct species in the course of evolution.
"Geographic isolation is one of the primary drivers of speciation."
homologous
adjectiveHaving the same relation, relative position, or structure, especially through evolutionary origin.
"The wing of a bat and the arm of a human are homologous structures."
phylogenetic
adjectiveRelating to the evolutionary development and diversification of a species or group.
"Phylogenetic analysis suggests the two species diverged approximately 12 million years ago."
epigenetic
adjectiveRelating to changes in gene expression that do not involve alterations to the DNA sequence itself.
"Epigenetic factors may account for phenotypic variation not explained by genetic differences."
adaptive radiation
nounThe diversification of a group of organisms into forms filling different ecological niches.
"Darwin's finches remain the classic example of adaptive radiation."
convergent evolution
nounThe independent evolution of similar features in species of different lineages.
"The eye has evolved independently multiple times — a striking example of convergent evolution."
Grammar Focus
Scientific hedging — tentative conclusions, limitations, and degrees of certainty
Scientific English requires precise calibration of certainty. Strong hedges: "may," "might," "could," "it is possible that." Moderate hedges: "appears to," "seems to," "tends to," "is likely to." Weak hedges (near-certainty): "strongly suggests," "provides compelling evidence." Limitation language: "within the constraints of," "given the limitations of the sample," "it should be noted that." Results are rarely stated as absolute: "The data are consistent with..." rather than "The data prove..."
These findings appear to be consistent with the hypothesis, though further research is warranted.
It is conceivable that epigenetic factors may play a more significant role than previously recognised.
The data strongly suggest a correlation, though causation cannot be definitively established.
Given the limitations of the sample size, these results should be interpreted with appropriate caution.
Exercises
Exercise 1
Rewrite each statement to include appropriate scientific hedging. The current version is too absolute.
1. Too absolute: "This gene causes the disease." Hedged:
2. Too absolute: "The species went extinct because of climate change." Hedged:
3. Too absolute: "Epigenetics disproves the central dogma of molecular biology." Hedged:
4. Too absolute: "Our experiment proves the theory." Hedged:
5. Too absolute: "All variation is genetic." Hedged:
Exercise 2
Choose the hedging expression that best conveys the intended degree of certainty.
1. The researcher is 90% confident in the finding: "The data ___ a strong link between habitat loss and population decline."
2. The researcher is only slightly confident: "It ___ that dietary factors play some role."
3. The researcher acknowledges a limitation: "___ the relatively small sample, these results should be interpreted cautiously."
4. The researcher states a moderate probability: "The two species ___ have diverged during the Miocene epoch."
5. The researcher refuses to overclaim: "While suggestive, the evidence ___ warrant a definitive conclusion."
Reading
The Cautious Science
Evolutionary biology is, in one sense, a science of overwhelming confidence: the evidence for evolution by natural selection is as robust as any finding in the natural sciences, and no credible alternative framework exists. Yet the language in which evolutionary biologists communicate their findings is, paradoxically, saturated with caution. A paper might report that a trait "appears to have been selected for," that two species "may have diverged approximately" a given number of years ago, or that a particular adaptation "is consistent with" a specific selective pressure. This hedging is not timidity but epistemic rigour. Evolutionary biology deals in deep time and incomplete fossil records; it reconstructs events that occurred millions of years ago from fragmentary evidence. Given the inherent limitations of the available data, overclaiming would be not merely imprudent but unscientific. The distinction between "suggests" and "demonstrates," between "is consistent with" and "proves," is not merely stylistic but epistemological. It reflects a discipline's commitment to calibrating its claims to the strength of the underlying evidence. Students of scientific English must learn to read these hedges not as weakness but as precision — and to deploy them with equal care in their own writing.
1. Why does the passage describe the hedging language of evolutionary biology as "epistemic rigour" rather than "timidity"?
2. What distinction does the passage draw between "suggests" and "demonstrates"?
Speaking
Discuss these questions with a partner or your teacher.
Writing
Write a short results paragraph (100-130 words) for an imaginary scientific study. Use at least four different hedging expressions to appropriately qualify your findings.
Example: The data appear to indicate a statistically significant correlation between canopy density and avian species diversity (r = 0.73, p < 0.01). These findings are broadly consistent with the hypothesis that habitat complexity promotes biodiversity, though it should be noted that the study was conducted at a single site, and generalisability may therefore be limited. It is conceivable that confounding variables, such as proximity to water sources, could account for a portion of the observed variance. Further research, ideally involving multiple sites and longitudinal data, would be necessary to establish a more robust causal relationship.
Answer Key — For Teacher Use
Exercise 1
1. This gene appears to be strongly associated with the disease, though the precise causal mechanism remains to be fully elucidated. · 2. Available evidence suggests that climate change may have been a significant contributing factor in the species' extinction. · 3. Epigenetic findings appear to complicate, if not challenge, certain aspects of the traditional central dogma. · 4. Our findings are consistent with the theory and lend further support to its central claims. · 5. While genetic factors account for a substantial proportion of observed variation, environmental and epigenetic influences likely play a non-trivial role.
Exercise 2
1. strongly suggest · 2. is conceivable · 3. Given · 4. appear to · 5. does not yet
Reading Comprehension
1. Because evolutionary biology deals with deep time and fragmentary evidence; hedging calibrates claims to the actual strength of the evidence, making it a mark of scientific precision rather than weakness. · 2. The distinction is epistemological, not merely stylistic — it reflects different degrees of evidentiary support. "Suggests" indicates the evidence is compatible but not conclusive, while "demonstrates" implies much stronger proof.