Neolithic populations generally had short life expectancies and more labor intensive lifestyle then hunter-gatherers. While, hunter-gatherers collect wild plants and they also pursuing wild animals.
How did humans impacted the environment? Well, overpopulation, pollution, burning fossil fuels, and deforestation. Deforestation is a huge change. A lot of animals and plant species have been extinct due to that. These changes have caused climate change, poor air quality, and many more.