DDIG: Was There a Sensory Trade-off in Primate Evolution? A method of tracing vomerolfaction in the fossil record

在体质人类学中有一个长期存在的假设，即在灵长类进化中，嗅觉和视觉之间发生了感官权衡。这种权衡被认为是在灵长类动物适应白天而不是夜间活动模式的过程中发生的。 因此，这些灵长类动物开始在交流中使用视觉刺激，而不是嗅觉或化学感觉。虽然这种权衡假设似乎支持减少相关的信息素检测和增强的视觉系统在一些活的灵长类动物的解剖结构，它还没有被测试使用化石记录。化石在很大程度上被排除在回答这个问题之外，因为与化学感觉有关的特征，特别是在信息素检测中很重要的犁鼻器，并不重要。本研究确定了灵长类动物的化学感觉相关的骨骼解剖特征，以了解这些特征在活灵长类动物中的表达变化，并将所得信息与化石灵长类动物进行比较。 我们已经确定了一个硬组织相关的灵长类动物化学感觉的形式，双边骨槽的鼻底，形成关节周围犁鼻器官的软骨。利用组织学和CT方法，对一系列现存灵长类动物的腭沟及其与犁鼻器的关系（发生率、相对大小）进行了统计学分析。 还将使用CT检查保存鼻底的化石灵长类动物的头骨，以确定腭槽的存在，大小和形态，以了解灵长类动物化学感觉减少的时间和背景，并测试这是否证实了感觉权衡假设。这项研究促进了研究生教育，并将导致博士学位。一个女研究生 从这个项目中恢复的数据将增加对早期灵长类动物生态学和适应界面的了解，并为理解人类化学感觉的减少提供信息。这项研究将通过期刊和科学杂志向科学界和感兴趣的公众提供。

There is a long-standing hypothesis in physical anthropology that a sensory trade-off has occurred between smell and vision in primate evolution. This trade-off is suggested to have taken place during the time that anthropoid primates adapted to a diurnal rather than nocturnal activity pattern. Thus, these primates began using visual stimuli more prominently than smell or chemosensation in communication. While this trade-off hypothesis seems supported by reduction in the anatomical structures related to pheromone detection and enhancement of the visual system in some living primates, it has not been tested using the fossil record. Fossils have largely been excluded from answering this question because features related to chemosensation, particularly the vomeronasal organs, which are important in pheromone detection, do not fossilize. This study identifies bony anatomical features related to chemosensation in primates to understand variation in the expression of these features in living primates and compare the resultant information to fossil primates. We have identified a hard-tissue correlate of primate chemosensation in the form of bilateral bony grooves on the nasal floor, formed by articulation with the cartilage surrounding the vomeronasal organs. The palatal grooves and their relationship to the vomeronasal organs (occurrence, relative size) are analyzed statistically in a range of living primates using histological and CT methods. Skulls of fossil primates that preserve the nasal floor will are also examined using CT to identify the presence, size and morphology of the palatal grooves to understand the timing and context of the reduction of chemosensation in anthropoid primates and test whether this corroborates the sensory trade-off hypothesis.This research promotes graduate education and will result in a Ph.D. for a female graduate student. The data recovered from this project will increase knowledge on the interface of ecology and adaptation in early primates as well as contributing information to understanding reduction of human chemosensation. This research will be made available to the scientific community and the interested public through journals and scientific magazines.