概括
已灭绝的棉鼠,Sigmodon小,在多个地点从Sigmodon中等进化. 证据表明,这些化石动物在堪萨斯州和亚利桑那州的种群中发生了平行进化.
科学领域:
- 古生物学的古生物学
- 进化生物学 进化生物学
- 哺乳动物学 哺乳动物学
背景情况:
- 在堪萨斯州和亚利桑那州发现了灭绝的棉鼠,Sigmodon minor和Sigmodon medius的化石遗骸,属于中等物种群.
- 众所周知,小西格莫登是从中小西格莫登进化而来的.
研究的目的:
- 调查Sigmodon小种群与Sigmodon中等种群的进化起源.
- 确定小西格莫登的进化是否在不同地理位置独立发生.
主要方法:
- 对来自堪萨斯州和亚利桑那州的Sigmodon minor和Sigmodon medius化石遗骸的分析.
- 对形态学和地层学数据进行比较分析,以推断进化关系和人口起源.
主要成果:
- 有证据表明,堪萨斯州的Sigmodon minor种群起源于堪萨斯州的Sigmodon medius种群.
- 同样,亚利桑那州的Sigmodon minor种群似乎起源于亚利桑那州的Sigmodon medius种群.
- 这表明Sigmodon minor.物种的多重并行起源.
结论:
- 西格莫登小从西格莫登中等的进化至少在两个不同的地理区域 (堪萨斯州和亚利桑那州) 独立发生.
- 这一发现为哺乳动物提供了多种物种起源的例子,与人类亚种进化的理论相比较.
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