Data from: Spatial patterns and rarity of the white-phased ‘Spirit Bear’ allele reveals gaps in habitat protection

Preserving genetic and phenotypic diversity can help safeguard not only
biodiversity but also cultural and economic values. Here, we present data
that emerged from Indigenous-led research at the intersection of evolution
and ecology to support conservation planning of a culturally salient,
economically valuable, and rare phenotypic variant. We addressed three
conservation objectives for the white-phased ‘Spirit bear’ polymorphism, a
rare and endemic white-coated phenotype of black bear (Ursus americanus)
in Kitasoo/Xai’xais and Gitga’at Territories and beyond in coastal British
Columbia, Canada. First, we used non-invasively collected hair samples (n
= 385 bears over ~18,000 km2) to assess the spatial variation in the
frequency of the allele that controls the white-coloured morph (mc1r).
Second, we compared our observed allele frequencies at mc1r with those
expected under Hardy-Weinberg equilibrium. Finally, we examined how well
current protected areas in the region aligned with spatial hotspots of
Spirit bear alleles. We found that landscape-level allele frequency was
lower than previously reported. For example, our systematic sampling
estimated a frequency of 0.25 (95% CI 0.13-0.41) on Gribbell Island
compared with the previously reported estimate of 0.56. Also, in contrast
with previous reports, we failed to detect a statistically significant
departure from Hardy-Weinberg equilibrium at mc1r, which calls into
question the previously-posited role of homozygote gene flow, heterozygote
disadvantage, and positive assortative mating in the maintenance of this
polymorphism. Finally, we found a discrepancy between the placement of
protected areas and the 90th percentile hotspots (upper 10% of all
estimated values) of Spirit bear alleles, with ~50% of hotspots falling
outside of protected areas. These results provide new insight into
hypotheses related to the maintenance of this rare polymorphism, and
directly relevant information to support evidence-based opportunities for
Indigenous Nations of the area to attend to gaps in conservation planning.

保护遗传与表型多样性，不仅可维系生物多样性，亦能守护文化与经济价值。本研究依托演化与生态学交叉领域的原住民主导研究生成的数据，旨在为一类兼具显著文化意义、经济价值与稀有表型变异的物种的保护规划提供支撑。我们针对加拿大不列颠哥伦比亚省沿海基塔苏/赛克赛斯（Kitasoo/Xai’xais）与吉特加特（Gitga’at）领地及周边区域内的白色型‘灵熊（Spirit bear）’多态性——即美洲黑熊（Ursus americanus）的稀有地方性白色被毛表型——设定了三项保护目标：其一，利用在约18000平方千米范围内非侵入性采集的385份黑熊毛发样本，评估控制白色毛发形态的mc1r等位基因频率的空间变异特征；其二，将观测得到的mc1r等位基因频率与哈迪-温伯格平衡（Hardy-Weinberg equilibrium）下的理论预期频率进行对比；其三，分析该区域当前的保护区布局与灵熊等位基因空间热点的契合度。我们发现，景观尺度下的等位基因频率低于既往报道结果：例如，经系统抽样估算，格里贝尔岛（Gribbell Island）的等位基因频率为0.25（95%置信区间：0.13~0.41），而既往报道值为0.56。此外，与既往研究结果不同的是，我们未检测到mc1r位点存在统计学意义上显著偏离哈迪-温伯格平衡的情况，这对此前提出的‘纯合子基因流、杂合子劣势与正向选型交配维持该多态性’的相关假说提出了质疑。最后，我们发现保护区布局与灵熊等位基因90百分位数热点区域（即所有估算值中前10%的区域）存在错位，约50%的热点区域未被纳入保护区范围。本研究结果为该稀有多态性维持相关假说提供了新的认知视角，同时为当地原住民部族依据实证完善保护规划、填补保护空白提供了直接参考依据。