If ancient populations such as hunter-gatherers and Inuit had a high incidence of cardiovascular disease, the unavoidable conclusion is that cardiovascular problems are at least half genetic.

This is a conditional inference: judge whether the conclusion that cardiovascular problems are 'at least half genetic' is supported. True: the evidence shows substantial cardiovascular disease or atherosclerosis in ancient and pre-industrial populations (for example in mummy CT studies, among hunter-gatherers, or among the Inuit), and heritability estimates or genetic research support a genetic contribution of about 50% or more to cardiovascular disease risk. Mostly true: heritability estimates cluster near 40–60%, so 'at least half' is roughly right, and the premise holds. Mixed: the premise holds but heritability estimates fall clearly below half (for example around 30–40%), or the evidence is evenly split. Mostly false: ancient disease prevalence is real, but non-genetic causes (for example smoke inhalation, infection, inflammation or diet) explain it and the genetic share is well below half, so the inference turns prevalence into heritability without support. False: the evidence shows that ancient populations had little cardiovascular disease, or that the genetic contribution is minor.

Set before the research began.

1. E1 Rare variant contribution to the heritability of coronary artery disease - Nature Communications Nature Communications · 9 October 2024

   “Twin studies reported a strong genetic basis of CAD, with heritability estimates ranging from ~40–60% in North European populations”

2. E2 Rare variant contribution to the heritability of coronary artery disease - Nature Communications Nature Communications · 9 October 2024

   “We estimate CAD heritability at 34.3% assuming a prevalence of 8.2%.”

3. E3 Atherosclerosis in ancient mummified humans: the global HORUS study Oxford Academic (European Heart Journal) · 9 July 2024

   “Definite or probable atherosclerosis was seen in 89 (37.6%) mummies.”

4. E4 Atherosclerosis in ancient mummified humans: the global HORUS study Oxford Academic (European Heart Journal) · 9 July 2024

   “These findings support the existence of an innate human predisposition to atherosclerosis. Modern cardiovascular risk factors superimposed on an underlying, inherent risk may drive the extent and impact, rather than the basic prevalence risk, of atherosclerosis.”

The premise holds: the HORUS mummy CT study found definite or probable atherosclerosis in 37.6% of ancient mummies, and its authors describe an innate human predisposition (E3, E4). However, the same authors suggest that modern risk factors may drive the extent and impact of disease, and they give no genetic share (E4). Heritability estimates are split: twin studies give about 40–60% for coronary artery disease (E1), while a genome-based estimate is 34.3% (E2). Because the estimates bracket or fall below half, the evidence does not clearly support "at least half genetic," which fits the mixed category.