The spatial distribution of biomes has changed considerably over deep time, so the geographical opportunity for an evolutionary lineage to shift into a new biome may depend on how the availability and connectivity of biomes has varied temporally. To better understand how lineages shift between biomes in space and time, we developed a phylogenetic biome shift model in which each lineage shifts between biomes and disperses between regions at rates that depend on the lineage's biome affinity and location relative to the spatiotemporal distribution of biomes at any given time. To study the behavior of the biome shift model in an empirical setting, we developed a literature-based representation of paleobiome structure for three mesic forest biomes, six regions, and eight time strata, ranging from the Late Cretaceous (100 Ma) through the present. We then fitted the model to a time-calibrated phylogeny of 119 Viburnum species to compare how the results responded to various realistic or unrealistic assumptions about paleobiome structure. Ancestral biome estimates that account for paleobiome dynamics reconstructed a warm temperate (or tropical) origin of Viburnum, which is consistent with previous fossil-based estimates of ancestral biomes. Imposing unrealistic paleobiome distributions led to ancestral biome estimates that eliminated support for tropical origins, and instead inflated support for cold temperate ancestry throughout the warmer Paleocene and Eocene. The biome shift model we describe is applicable to the study of evolutionary systems beyond Viburnum, and the core mechanisms of our model are extensible to the design of richer phylogenetic models of historical biogeography and/or lineage diversification. We conclude that biome shift models that account for dynamic geographical opportunities are important for inferring ancestral biomes that are compatible with our understanding of Earth history.

中文翻译：

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模拟过去的星球上的系统发生生物群落转变

生物群落的空间分布在很长时间内发生了很大变化，因此进化世系转移到新生物群落的地理机会可能取决于生物群落的可用性和连通性如何随时间变化。为了更好地理解谱系在空间和时间之间在生物群落之间的转移，我们开发了系统发育的生物群落转移模型，其中每个谱系在生物群落之间转移并以相对于生物群落的时空分布相对于谱系的生物群落亲和力和位置而定的速率在区域之间分散。任何给定的时间。为了研究生物群落转移模型在经验背景下的行为，我们开发了基于文献的古生物组结构表示法，用于从晚白垩纪（100 Ma）到现在的三个中生森林生物群落，六个区域和八个时间层。 。然后，我们将模型拟合到119种荚burn物种的经过时间校准的系统发育，以比较结果如何响应有关古生物组结构的各种现实或不现实假设。祖先生物群落的估计，解释了古生物组动力学，重建了温暖的荚burn温带（或热带）起源，这与以前基于化石的祖先生物群落的估计是一致的。施加不切实际的古生物组分布导致祖先的生物群落估计，从而消除了对热带起源的支持，反而在古新世和始新世较暖的时期夸大了对冷温带祖先的支持。我们描述的生物群落转移模型适用于研究荚莲以外的进化系统，并且我们模型的核心机制可扩展到历史生物地理学和/或宗族多样化的更丰富的系统发育模型的设计。我们得出结论，解释动态地理机会的生物群落转移模型对于推断与我们对地球历史的理解相适应的祖先生物群落至关重要。