Evolutionary theory is firmly grounded on the existence of trade-offs between life-history
traits, and recent interest has centred on the physiological mechanisms underlying such …

Larger testes are considered the quintessential adaptation to sperm competition. However,
the strong focus on testis size in evolutionary research risks ignoring other potentially …

Mating with multiple partners is common across species, and understanding how individual
males secure fertilization in the face of competition remains a fundamental goal of …

Sperm competition typically favours an increased investment in testes, because larger testes
can produce more sperm to provide a numerical advantage in competition with rival …

When ejaculates from rival males compete for fertilization, there is strong selection for sperm
traits that enhance fertilization success. Sperm quantity is one such trait, and numerous …

The outcome of sperm competition is influenced by the relative quantity and quality of sperm
among competing ejaculates. Whereas it is well established that individual ejaculate traits …

In the non-equatorial zones of the Earth, species concentrate their reproductive effort in the
more favorable season. A consequence of seasonal breeding is seasonal testis regression …

Understanding causes of between-sex differences in survival patterns is a long-standing
challenge in evolutionary biology. Interspecific differences in male allocation to sexual …

The hypothesis that sperm competition should favour increases in sperm size, because it
results in faster swimming speeds, has received support from studies on many taxa, but …

In this study, we aimed to explore the potential differences in proteomic profiles from the
testicular tissue of azoospermatic men with impaired spermatogenesis and normal …