评论"死在阳光下:直接证据显示,在波斯纪末期的大规模灭绝时,紫外线B辐射升高"
Alistair W R Seddon1, Boris Zimmermann2
1Department of Biological Sciences and Bjerknes Center for Climate Research, University of Bergen, Bergen, Norway.
Science advances
|August 25, 2023
概括
这项研究挑战了先前的发现,表明在珀米纪末期大灭绝化石中提出的UV-B吸收化合物没有可靠地检测到. 分析表明信号是弱的和误解,质疑在这个灭绝事件期间UV-B辐射的直接证据.
科学领域:
- 古生物学的古生物学
- 地质化学 地质化学
- 频谱学是一种光谱学.
背景情况:
- 珀米纪末期的大规模灭绝是地球历史上一个重要事件.
- 紫外线B (UV-B) 辐射已被提议为潜在的灭绝驱动因素.
- 福里埃变换红外光谱法 (FTIR) 已被用于检测化石形体中的UV-B吸收化合物.
研究的目的:
- 重新评估证据,证据表明,在珀米纪末期大规模灭绝时,化石形体中,UV-B吸收化合物的丰富度增加.
- 评估FTIR光谱学在化石样本中量化这些化合物的可靠性.
- 批判性地检查以前研究中使用的方法及其解释.
主要方法:
- 在末珀米纪灭绝间隔中,从化石化形体中分析FTIR光谱.
- 评估信号噪声比率和背景干扰,特别是来自水蒸气的干扰.
- 评估峰值检测方法及其对分析频谱的适用性.
- 检查光谱基线变化及其对化合物量化的潜在影响.
主要成果:
- 发现UV-B吸收化合物的向光谱信号很弱,分辨率很差.
- 非随机的背景干扰,可能来自水蒸气,显著影响了光谱.
- 以前使用的峰值检测方法被认为不合适,只选择了相关光谱数据的一小部分.
- 重建的变化归因于基线变化,而不是UV-B吸收化合物的实际变化.
结论:
- 在基于分析的化石记录的基础上,在波斯末期大规模灭绝时观察到UV-B辐射的直接证据的说法没有得到支持.
- 以前使用的FTIR光谱数据和分析方法不足以自信地将光谱变化归因于吸收UV-B的化合物.
- 需要通过改进的光谱技术和数据分析进行进一步的研究,以调查紫外线B辐射在过去的灭绝事件中的作用.
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