Changes in maternal investment in eggs can affect population dynamics

Area of Science:

• Ecology
• Evolutionary Biology
• Population Dynamics

Background:

• Maternal provisioning strategies significantly influence offspring performance and life history.
• Theoretical models suggest maternal effects can drive population cycles, but empirical evidence is limited.
• Previous research faced challenges in conducting simultaneous individual and population-level experiments.

Purpose of the Study:

• To investigate the maternal effect trade-off between fecundity and per-egg provisioning in Sancassania berlesei.
• To determine how maternal food availability and age influence this trade-off.
• To assess the multi-generational impact of maternal effects on population dynamics.

Main Methods:

• Conducted experiments on the soil mite Sancassania berlesei.
• Manipulated maternal provisioning by controlling food availability and age.
• Initiated populations with eggs of varying mean sizes to observe population dynamics over generations.

Main Results:

• A trade-off exists between maternal fecundity and protein provisioning per egg, influenced by maternal food and age.
• Populations initiated with different egg sizes exhibited distinct population dynamics for at least three generations.
• Initial cohort differences in growth, maturation, and fecundity affected subsequent generations' competitive environments and life histories.

Conclusions:

• Maternal effects can have significant, long-lasting consequences on population dynamics.
• These effects can cascade across generations by altering competitive environments.
• Maternal effects may play a crucial role in population dynamics, especially in temporally variable environments.