Complex growth rate evolution in a latitudinally widespread species

Area of Science:

• Evolutionary Biology
• Herpetology
• Ecology

Background:

• Somatic growth rate evolution is complex, especially in viviparous ectotherms where maternal environment influences offspring development.
• Local adaptation to environmental conditions across a species' range is crucial for understanding growth rate variation.
• The role of the maternal gestation environment in shaping post-parturition growth in reptiles remains underexplored.

Purpose of the Study:

• To investigate the sources of variation in somatic growth rates in the viviparous reptile Eulamprus quoyii.
• To determine the influence of maternal environment and local conditions on offspring growth rates.
• To examine the evolutionary implications of local adaptation to maternal gestation environments in viviparous ectotherms.

Main Methods:

• Collected pregnant female Eulamprus quoyii from tropical and temperate range margins.
• Completed gestation in controlled environments simulating local thermal and photoperiod conditions.
• Monitored offspring growth rates from birth through to maturity, assessing compensatory growth.

Main Results:

• Demonstrated complex growth rate evolution between northern and southern Eulamprus quoyii populations.
• Identified local adaptation of growth rates to maternal environments, with effects persisting post-parturition.
• Observed that in utero-entrained growth differences were maintained despite compensatory growth mechanisms.

Conclusions:

• Local adaptation to maternal gestation environments significantly impacts somatic growth rates in viviparous ectotherms.
• Understanding adaptation to maternal environments is key to comprehending the evolution of growth rates and viviparity.
• Local adaptation to gestation environments may confer a selective advantage in the evolution of viviparity.