RT Journal Article
SR Electronic
T1 Evolutionary trade-off in reproduction of Cambrian arthropods
JF Science Advances
JO Sci Adv
FD American Association for the Advancement of Science
SP eaaz3376
DO 10.1126/sciadv.aaz3376
VO 6
IS 18
A1 Ou, Qiang
A1 Vannier, Jean
A1 Yang, Xianfeng
A1 Chen, Ailin
A1 Mai, Huijuan
A1 Shu, Degan
A1 Han, Jian
A1 Fu, Dongjing
A1 Wang, Rong
A1 Mayer, Georg
YR 2020
UL http://advances.sciencemag.org/content/6/18/eaaz3376.abstract
AB Trade-offs play a crucial role in the evolution of life-history strategies of extant organisms by shaping traits such as growth pattern, reproductive investment, and lifespan. One important trade-off is between offspring number and energy (nutrition, parental care, etc.) allocated to individual offspring. Exceptional Cambrian fossils allowed us to trace the earliest evidence of trade-offs in arthropod reproduction. †Chuandianella ovata, from the early Cambrian Chengjiang biota of China, brooded numerous (≤100 per clutch), small (Ø, ~0.5 mm) eggs under carapace flaps. The closely related †Waptia fieldensis, from the middle Cambrian Burgess Shale of Canada, also brooded young, but carried fewer (≤ 26 per clutch), larger (Ø, ~2.0 mm) eggs. The notable differences in clutch/egg sizes between these two species suggest an evolutionary trade-off between quantity and quality of offspring. The shift toward fewer, larger eggs might be an adaptive response to marine ecosystem changes through the early-middle Cambrian. We hypothesize that reproductive trade-offs might have facilitated the evolutionary success of early arthropods.