International Journal of Primatology ( IF 2.5 ) Pub Date : 2021-03-31 , DOI: 10.1007/s10764-021-00206-6 Mark F. Skinner
A geographically and temporally widespread pattern of repetitive episodes of developmental stress, recorded as furrows of linear enamel hypoplasia (LEH) in most recent and fossil apes, requires explanation. I compared observations of LEH recurrence among museum specimens of Pan troglodytes and Pan paniscus with historical weather records of seasonally recurrent combinations of lower temperature, higher rain and wind (“cold discomfort”). I imaged samples of 34 canine teeth (N = 20 animals, 54 independent LEH) from P. troglodytes from Fongoli, Senegal, and Taï Forest, Côte d’Ivoire and P. paniscus from the Democratic Republic of Congo with a scanning electron microscope and counted perikymata between and within LEH events. I converted counts to time using published Retzius periodicities (the number of days taken to form enamel layers, visible in thin sections) and compared their recurrence and duration to seasonal peaks of incidence and the intensity of cold discomfort. Using the longest Retzius periodicity (9 days), chimpanzees and bonobos show LEH lasting about 7–9 weeks, respectively, recurring annually. Most bonobos also show just-under semiannual recurrence of LEH. “Colder, wetter, windier” weeks recur annually at the P. troglodytes locations and semiannually at P. paniscus sites. When the combination of “below median temperatures, above median rain and winds” peaks in intensity and incidence over a 7-week period, daily “minimum hourly” temperatures average 20–21°C (7–9°C below lower critical body temperature for chimpanzees) with wind 3 times and rainfall 30 times higher than usual. These findings suggest that seasonal cold discomfort may be an important factor in episodic enamel hypoplasia in many nonhuman primates.
中文翻译:
感冒不适:一种解释泛性穴居人和泛性潘氏菌中重复的线性釉质发育不全的模型
在最近的和化石猿类中,线性应激性牙釉质发育不全(LEH)的沟纹记录了发育压力重复发作的地理和时间分布格局,需要进行解释。我将潘氏穴居动物和潘氏潘氏菌的博物馆标本中LEH复发的观察结果与温度较低,雨水和风的季节性反复组合(“寒冷不适”)的历史气象记录进行了比较。我中成像的34周的犬齿(样品ñ从= 20组的动物,54独立LEH)P.穴居从Fongoli,塞内加尔,及大森林,科特迪瓦和P. paniscus来自刚果民主共和国的扫描电子显微镜,并计算了LEH事件之间和之内的角膜瘤。我使用已发布的Retzius周期性(形成釉层的天数,在薄片中可见)将计数转换为时间,然后将其复发和持续时间与发病率的季节性高峰和寒冷不适的强度进行比较。使用最长的Retzius周期(9天),黑猩猩和bo黑猩猩显示LEH分别持续约7–9周,每年重复。大多数bo黑猩猩也表现出LEH的半年复发。“更冷,湿润剂,多风”周在每年复发P.穴居位置和每半年在P. paniscus网站。当“低于中位数温度,高于中位数雨和风”的组合强度和发生率在7周内达到峰值时,每日“最低每小时”平均温度为20–21°C(低于下临界人体温度7–9°C) (黑猩猩)的风速比平时高3倍,而降雨则高30倍。这些发现表明,季节性冷不适可能是许多非人类灵长类动物偶发性釉质发育不全的重要因素。