早期人类起源演化的环境背景是国际上有很大争议的重大科学问题。泥河湾盆地是研究东亚人类演化与环境关系的理想地区之一，但该区古人类生存的气候环境背景、古湖的演化及其与古人类活动具有怎样的联系等因系统研究不足而不明确。本项目拟以该盆地有很好年代学基础、构成南-北向断面的4个剖面（从北到南；马圈沟、小长梁、红崖、花豹沟）为研究对象，建立旧石器遗址集中分布时段（1.8-0.8 Ma）较高分辨率的软体动物组合序列，研究软体动物化石保存状况和种类组成；通过现生种类的调查并参考前人资料，明确优势种类的生态环境意义，根据软体动物化石组合，结合岩性岩相变化，探讨该时期古湖的演化与古人类活动的联系；揭示软体动物组合的演替过程与气候变化特点，并与旧石器文化序列对比，重点研究古人类在泥河湾盆地生存的气候环境背景。本项目有望为人类演化的环境背景研究提供来自泥河湾盆地的新的生物学证据，有望促进我国古软体动物学科的发展。

The presence and evolution of early humans is thought to be closely related to the environment they lived. However, what kind of environment favorable for the origin and evolution of early humans remains highly debated. The Nihewan Basin is one of the best regions for the understanding of the environment that early humans had lived. As comprehensive studies of the environmental evolution in the Nihewan Basin are sparse, we know very little about the environment that early humans in East Asia had lived. In this project, four high-resolution fossil freshwater mollusk sequences will be established from the Nihewan Basin, covering the period of 1.8-0.8 Ma. Three objectives of the project are as follows: 1) to investigate the preservation conditions, species composition and ecological groups of the freshwater mollusk assemblages; 2) to examine the ecological significance of the modern mollusk species through investigating about 150 water bodies covering the region from Northeast China to middle Southeast China as well as based on the results provided by previous studies; 3) to reconstruct the history of ecological environmental changes in the Nihewan Basin during the time interval from 1.8 to 0.8 Ma based on ecological significance of the fossil mollusk species from the Nihewan Basin, discuss the characteristic of ecological environment and climate change during this period, and decipher the evolution of the Nihewan paleolake based on fossil mollusks and lithological changes. All of these efforts would provide environmental context when early humans lived in this basin. This project would be a significant contribution of freshwater mollusks to the understanding of ecological environmental changes related to the evolution of early humans in East Asia. It would also be of importance to the development of mollusk studies in China.