王俊凯的腿吧 关注：272贴子：46,665
关于大象
最大的争议点在于象牙。玩斗兽的部分票友最热衷于长牙象能不能以此对抗大型兽脚类，答案显而易见。不仅仅是象牙本身的问题，而是长牙在种内竞争中所起到的作用本身也极小。
The evolution of sexually dimorphic, elaborate male traits that are seemingly maladaptive may be driven by sexual selection (male–male competition and or female mate choice). Tusk possession in the Asian elephant is sexually dimorphic and exaggerated but its role in male–male competition has not yet been determined. We examined the role of the tusks in establishing dominance along with two other known male–male signals, namely, body size and musth (a temporary physiologically heightened sexual state) in an Asian elephant population in northeastern India with equal proportions of tusked and tuskless males. We observed 116 agonistic interactions with clear dominance outcomes between adult (>15 years) males during 458 field days in the dry season months of 2008–2011. A generalized linear mixed-effects model was used to predict the probability of winning as a function of body size, tusk possession and musth status relative to the opponent. A hierarchy of the three male–male signals emerged from this analysis, with musth overriding body size and body size overriding tusk possession. In this elephant population tusk possession thus plays a relatively minor role in male–male competition. An important implication of musth and body size being stronger determinants of dominance than tusk possession is that it could facilitate rapid evolution of tuskless males in the population under artificial selection against tusked individuals, which are poached for ivory.
出处放出，免得有人又说我信口雌黄
对于种内竞争而言，衡量一头公象是否强大，首当其冲是个头，其次是所处的狂暴期，最后才是象牙。
尤其是有相当多的例子都是长牙象难敌短牙象（当然牙太短的也不行，比如那种小荷才露尖尖角的）
像著名象王萨陶这种牙，多半是中看不中用的典型。
最大的争议点在于象牙。玩斗兽的部分票友最热衷于长牙象能不能以此对抗大型兽脚类，答案显而易见。不仅仅是象牙本身的问题，而是长牙在种内竞争中所起到的作用本身也极小。
The evolution of sexually dimorphic, elaborate male traits that are seemingly maladaptive may be driven by sexual selection (male–male competition and or female mate choice). Tusk possession in the Asian elephant is sexually dimorphic and exaggerated but its role in male–male competition has not yet been determined. We examined the role of the tusks in establishing dominance along with two other known male–male signals, namely, body size and musth (a temporary physiologically heightened sexual state) in an Asian elephant population in northeastern India with equal proportions of tusked and tuskless males. We observed 116 agonistic interactions with clear dominance outcomes between adult (>15 years) males during 458 field days in the dry season months of 2008–2011. A generalized linear mixed-effects model was used to predict the probability of winning as a function of body size, tusk possession and musth status relative to the opponent. A hierarchy of the three male–male signals emerged from this analysis, with musth overriding body size and body size overriding tusk possession. In this elephant population tusk possession thus plays a relatively minor role in male–male competition. An important implication of musth and body size being stronger determinants of dominance than tusk possession is that it could facilitate rapid evolution of tuskless males in the population under artificial selection against tusked individuals, which are poached for ivory.
出处放出，免得有人又说我信口雌黄
对于种内竞争而言，衡量一头公象是否强大，首当其冲是个头，其次是所处的狂暴期，最后才是象牙。
尤其是有相当多的例子都是长牙象难敌短牙象（当然牙太短的也不行，比如那种小荷才露尖尖角的）
像著名象王萨陶这种牙，多半是中看不中用的典型。
IP属地:江苏
2楼2022-03-31 15:19
2楼2022-03-31 15:19收起回复
对于狂暴期的作用，各类资料莫衷一是。
也有认为狂暴期最重要的，如下。
We observed 116 agonistic interactions with clear dominance outcomes between adult (>15 years) males during 458 field days in the dry season months of 2008e2011. A generalized linear mixed effects model was used to predict the probability of winning as a function of body size, tusk possession and musth status relative to the opponent. A hierarchy of the three male-male signals emerged from this analysis, with musth overriding body size and body size overriding tusk possession. In this elephant population tusk possession thus plays a relatively minor role in male-male competition. An important implication of musth and body size being stronger determinants of dominance than tusk possession
"Males with a musth advantage won irrespective of relative tusk status or body size except on two of the 86 occasions on which one of the males in the interacting pair was in musth. On the other hand, males with a tusk advantage did not always win: in 82 of 116 interactions a male had a tusk advantage over the opponent (Fig. 1a) and such males won 54 times and lost 28 times. However, 36 of these wins were associated with a musth advantage and 12 with a body size advantage, and thus only six wins could be attributed to a tusk advantage alone. The 28 losses show a clear pattern with respect to musth and body size disadvantage: 18 of these losses were to opponents with a musth advantage and eight to opponents with a body size advantage"
"In the 13 contests with a body size advantage of more than 10 cm and tusk asymmetry, the larger individual won irrespective of tusk status; tuskless males won seven and tusked males six of these 13 contests"
"The statistical model that best describes our data is P w b þ m þ t with musth having a greater influence on dominance outcome than tusk status"
."Musth and body size combined clearly overrode tusk status as an adult male emale signal of dominance in this population."
我个人是体重控，因此没有过多去找类似的说法，欢迎补充。
但无论怎么算，象牙的影响力都是位居末尾的。
（此外也有说法是衡量一头公象的力量需看象鼻上端，但目前我只在中文读物中见过，没有找到原出处，待定）
同时，公象与母象不能类比，内斗也不能用于亚非比较。
伦敦动物园（也可能是德国，记不得了，欧洲某地）中的员工目睹过亚洲象与非洲象的数十年争端（都是雌性），亚洲象起先居上，非洲象后来占优。在体型相差不大时，额头愈饱满的愈态度强硬，这点在雄象中没有例子支持。
也有认为狂暴期最重要的，如下。
We observed 116 agonistic interactions with clear dominance outcomes between adult (>15 years) males during 458 field days in the dry season months of 2008e2011. A generalized linear mixed effects model was used to predict the probability of winning as a function of body size, tusk possession and musth status relative to the opponent. A hierarchy of the three male-male signals emerged from this analysis, with musth overriding body size and body size overriding tusk possession. In this elephant population tusk possession thus plays a relatively minor role in male-male competition. An important implication of musth and body size being stronger determinants of dominance than tusk possession
"Males with a musth advantage won irrespective of relative tusk status or body size except on two of the 86 occasions on which one of the males in the interacting pair was in musth. On the other hand, males with a tusk advantage did not always win: in 82 of 116 interactions a male had a tusk advantage over the opponent (Fig. 1a) and such males won 54 times and lost 28 times. However, 36 of these wins were associated with a musth advantage and 12 with a body size advantage, and thus only six wins could be attributed to a tusk advantage alone. The 28 losses show a clear pattern with respect to musth and body size disadvantage: 18 of these losses were to opponents with a musth advantage and eight to opponents with a body size advantage"
"In the 13 contests with a body size advantage of more than 10 cm and tusk asymmetry, the larger individual won irrespective of tusk status; tuskless males won seven and tusked males six of these 13 contests"
"The statistical model that best describes our data is P w b þ m þ t with musth having a greater influence on dominance outcome than tusk status"
."Musth and body size combined clearly overrode tusk status as an adult male emale signal of dominance in this population."
我个人是体重控，因此没有过多去找类似的说法，欢迎补充。
但无论怎么算，象牙的影响力都是位居末尾的。
（此外也有说法是衡量一头公象的力量需看象鼻上端，但目前我只在中文读物中见过，没有找到原出处，待定）
同时，公象与母象不能类比，内斗也不能用于亚非比较。
伦敦动物园（也可能是德国，记不得了，欧洲某地）中的员工目睹过亚洲象与非洲象的数十年争端（都是雌性），亚洲象起先居上，非洲象后来占优。在体型相差不大时，额头愈饱满的愈态度强硬，这点在雄象中没有例子支持。
IP属地:江苏4楼2022-03-31 15:27
4楼2022-03-31 15:27收起回复
扫二维码下载贴吧客户端
下载贴吧APP
看高清直播、视频！
看高清直播、视频！
贴吧热议榜
- 1王祖贤在贴吧官宣创业2589090
- 2表白收到摩斯密码怎么破2027245
- 3AL淘汰JDG晋级决赛1885324
- 4分享我和妹妹难以启齿的故事1604205
- 5南师大博士女友出轨已婚导师1138878
- 6特朗普被说是俄国克格勃特工960075
- 7娜可露露重做野区霸主归来845160
- 8崩坏3.2遐蝶技能强度爆炸629119
- 9未来的农村宅基地还值钱吗462946
- 10尹锡悦的最终时刻即将到来461055
