Macroevolutionary Trade-Offs and Trends in Life History Traits of Cephalopods Through a Comparative Phylogenetic Approach

IBÁÑEZ MC; DÍAZ-SANTA ANA-ITURRIOS M; CARRASCO, S.A.; FERNÁNDEZ-ÁLVAREZ, F.A.; LÓPEZ-CORDOVA DA; CORNEJO CF; NICOLÁS ORTIZ; ROCHA F; VIDAL EAG; PARDO-GANADARILLAS, M.C.

FRONTIERS IN MARINE SCIENCE

Frontiers Media SA

Año: 2021 vol. 8

2296-7745

One of the major mechanisms responsible for the animals? fitness dynamics is fecundity.Fecundity as a trait does not evolve independently, and rather interacts by tradeoffswith other traits such as body and egg size. Here, our aim was to correctlyinfer the macroevolutionary trade-offs between body length, egg length, and potentialfecundity, using cephalopods as study model. The correlated evolution among thosetraits was inferred by comparative phylogenetic methods. Literature data on biologicaland reproductive traits (body length, egg length, and potential fecundity) were obtainedfor 90 cephalopod species, and a comparative phylogenetic method based on aprevious molecular phylogeny was used to test the correlated evolution hypothesis.Additionally, we estimated the phylogenetic signal and fitted five different evolutionarymodels to each trait. All traits showed high phylogenetic signal, and the selectedmodel suggested an evolutionary trend toward increasing body length, egg length, andfecundity in relation to the ancestral state. Evidence of correlated evolution betweenbody length and fecundity was observed, although this relationship was not detectedbetween body length and egg length. The robust inverse relationship between fecundityand egg length indicates that cephalopods evolved a directional selection that favoredan increase of fecundity and a reduction of egg length in larger species, or an increasein egg length with the concomitant reduction of fecundity and body length in order tobenefit offspring survival. The use of phylogenetic comparative methods allowed us toproperly detect macroevolutionary trade-offs.