Miner Emily J, Gurven Michael, Kaplan Hillard, Gaulin Steven J C
Department of Anthropology, University of California, Santa Barbara, CA 93106, USA.
Department of Anthropology, University of California, Santa Barbara, CA 93106, USA
Proc Biol Sci. 2014 Dec 7;281(1796):20141476. doi: 10.1098/rspb.2014.1476.
Sexual selection theory suggests that the sex with a higher potential reproductive rate will compete more strongly for access to mates. Stronger intra-sexual competition for mates may explain why males travel more extensively than females in many terrestrial vertebrates. A male-bias in lifetime distance travelled is a purported human universal, although this claim is based primarily on anecdotes. Following sexual maturity, motivation to travel outside the natal territory may vary over the life course for both sexes. Here, we test whether travel behaviour among Tsimane forager-horticulturalists is associated with shifting reproductive priorities across the lifespan. Using structured interviews, we find that sex differences in travel peak during adolescence when men and women are most intensively searching for mates. Among married adults, we find that greater offspring dependency load is associated with reduced travel among women, but not men. Married men are more likely to travel alone than women, but only to the nearest market town and not to other Tsimane villages. We conclude that men's and women's travel behaviour reflects differential gains from mate search and parenting across the life course.
性选择理论表明，具有较高潜在繁殖率的性别会为获得配偶而进行更激烈的竞争。在许多陆生脊椎动物中，雄性为争夺配偶而进行的种内竞争更为激烈，这或许可以解释为什么雄性比雌性的活动范围更广。一生旅行距离上的男性偏向被认为是人类的普遍现象，尽管这一说法主要基于轶事。性成熟后，两性离开出生地的旅行动机可能会在人生过程中发生变化。在此，我们测试了齐曼内觅食园艺者的旅行行为是否与一生中不断变化的生殖优先事项相关。通过结构化访谈，我们发现旅行中的性别差异在青春期达到峰值，此时男性和女性都在最积极地寻找配偶。在已婚成年人中，我们发现子女抚养负担加重与女性旅行减少有关，但与男性无关。已婚男性比女性更有可能独自旅行，但只前往最近的集镇，而不是其他齐曼内村庄。我们得出结论，男性和女性的旅行行为反映了在人生过程中寻找配偶和养育子女所带来的不同收益。
