NatureContemporaryglobalhigh confidence

Venom has evolved independently at least four times within eulipotyphlan mammals, more than in all other mammal groups combined.

Notes on verification

Directly supported by peer-reviewed PNAS study (Casewell et al. 2019) with verbatim matching claims in abstract; corroborated by PubMed/PMC mirrors. No contradicting sources found post-2019. [tier=silver indep_score=1.0 clusters=2 claim_tier=notable | kind=empirical eligibility=high (extractor: empirical/medium)]

Sources

Venom has evolved independently at least four times withi… · DeepInquiry