Elevational Goldilocks zone underlies the exceptional diversity of an Andean lizard radiation (Liolaemus; Liolaemidae)

Mountains are among the most biodiverse regions on the planet, and how these landforms shape diversification through the interaction of biological traits and geo-climatic dynamics is integral to understanding global biodiversity. In this study we investigate the dual roles of climate change and mountain uplift on the evolution of a hyper diverse radiation, Liolaemus lizards, with a spatially explicit model of diversification using a reconstruction of uplift and paleotemperature in central and southern South America. The diversification model captures a hotspot for Liolaemus around 40°S in lineages with low dispersal ability and narrow niche breadths. Under the model, speciation rates are highest in low latitudes (<35°S) and mid-elevations (~1000m), while extinction rates are highest at higher latitudes (>35°S) and higher elevations (>2000m). Temperature change through the Cenozoic explained variation in speciation and extinction rates through time and across different elevational bands. Our results point to the conditions of mid-elevations being optimal for diversification (i.e., Goldilocks Zone), driven by the combination of (1) a complex topography which facilitates speciation during periods of climatic change, and (2) a relatively moderate climate which enables the persistence of ectothermic lineages and buffers species from extinction.

Methods
We collated occurrence records for 7220 locations of 297 described and candidate species. These records were obtained from the Global Biodiversity Information Facility (GBIF), the scientific literature and museum records, and were carefully curated for errors, inaccuracies and taxonomic updates. We followed the taxonomy and distributions provided by Abdala et al. (2021) as a reference to clean the dataset. 

We simulated 500 clades under a range of model parameters using the Gen3sis engine. 

We provide raw occurence record data for Liolaemus (SI_data_1), the raw paleoenvironmental reconstructions of tempreature and elevation (SI_data_7, SI_data_8), as well as summary of simulated data (SI_data_2), summarised spatial patterns of emprical and simulated data across grid cells (SI_data_3) and elevational bands (SI_data_4, SI_data_5, SI_data_9), and summarised phylogenetic data (SI_data_6).

山地是地球上生物多样性最为丰富的区域之一，阐明这类地貌如何通过生物性状与地质气候动态的相互作用调控物种分化，对于理解全球生物多样性格局至关重要。本研究基于南美中南部的山地隆升与古温度重建数据，构建物种分化的空间显式模型，探究气候变化与山地隆升对高度多样化辐射类群——平鳍蜥属（Liolaemus）蜥蜴演化的双重作用。
该物种分化模型识别出，在扩散能力较弱、生态位宽度较窄的平鳍蜥属支系中，南纬40°附近区域为物种分化热点。模型结果显示，物种形成速率在低纬度（<35°S）与中海拔（约1000米）区域达到峰值，而灭绝速率则在高纬度（>35°S）与高海拔（>2000米）区域最高。新生代以来的温度变化，可以解释不同时间尺度以及不同海拔带内物种形成与灭绝速率的差异。本研究结果表明，中海拔环境是物种分化的最优条件（即金发姑娘适宜带），其驱动因素包含两点：其一，复杂的地形在气候变化时期可促进物种形成；其二，相对温和的气候能够支持外温支系存续，并为物种提供灭绝缓冲。

方法
我们整合了297个已描述物种与候选物种的7220条分布记录。这些数据来源于全球生物多样性信息设施（Global Biodiversity Information Facility, GBIF）、科学文献以及博物馆标本记录，并经过严格校验以修正误差、去除不准确信息并更新分类学命名。本研究以Abdala等人（2021）提出的分类体系与分布范围作为参考，对数据集进行清洗整理。
我们借助Gen3sis引擎，基于一系列模型参数模拟了500个演化支。
本研究附带提供以下数据集：平鳍蜥属的原始分布记录数据（SI_data_1）、温度与海拔的古环境重建原始数据（SI_data_7、SI_data_8）、模拟数据汇总结果（SI_data_2）、网格单元与海拔带内实测与模拟数据的空间格局汇总（SI_data_3、SI_data_4、SI_data_5、SI_data_9），以及系统发育数据汇总（SI_data_6）。