297. Social monogamy
Monogamy is not natural, and is uncommon among nonavian warm-bloods. Since monogamy lower a male’s chances of producing as many offspring as possible .
The reason is to ensure their young were not killed by other male. Based on 230 primate species over several generation, the male would balance A and B. This is the first time that the theory showing that infanticide is the driver of monogamy.
Based on another research, which has wider sample, there is no correlation between infanticide and monogany, but due to the location and supply. Monogamy is the result of resources defending.
Human monogamy is bother acquired taste and social necessity.
Monogamy - uncommon due to decrease offspring
Why?
1.Ensure their young were not killed>> survived to carry gene
- balanced spread vs protection
Kill young to breed with mother >> father to protect >> mother reproduce sooner
2.Wdier sample: no connection b/w infanticide and monogamy >> location + supply
- females live at low density, too many suitors
>> to ensure female only care about his own child
Resources defense: females intolerant of other females
Ungulates >> nutritional needs great >> fight for resources
Human: take longer so need to protect children
Questions remain
引出问题(为什么有哺乳动物会一夫一妻):一夫一妻制是违反动物天性的,减少繁衍率。
原因1:PNAS认为ensure the survival of their babies. CO :still long-running debate
原因2:DL TC repute reason1,suggest:location and supply of low density.(resource defense)
人类一夫一妻:protect childing-rearing female. Author:more desirable.
P2:
一个原因:
PNAS的报告:与female在一起的male保证他们的年轻孩子不被其他male杀死,以延续基金。
基于230中主要品种抚育和父母的表现,研究者觉得males平衡了基因池对抗需要保护年轻后代被杀死的传播的需求。进攻的males需要杀死年轻的后代,以此breed他的母亲。所以父亲在周边保护基因链,帮助抚育子嗣,母亲还能再很快生育。
这是evolution of monogamy理论首次被系统的测试,结果显示出infanticide是monogamy的驱动。
P3:
另一个研究:(反驳前一个原因)
Science杂志:用相似的分析方式,但是用了更大的样本(2500种物种)。
Dieter Lukas and Tim Clutton-Brock:infanticide和monogamy没有关联,而是location and supply影响的。
-Monogamy在females低密度的地方产生。这是资源斗争的结果。
females会对其他females不可忍耐,不像rarely monogamous的物种,这种哺乳动物的营养需求更大,所以与竞争者竞争食物资源。