Squeaks built a pretend time machine, and he and Mister Brown use their imaginations to travel back in time to learn all about the very first living thing! Second Grade Next Generation Science Standards Disciplinary Core Ideas: LS4.D: Biodiversity and Humans - There are many different kinds of living things in any area, and they exist in different places on land and in water (2-LS4-1). ESS1.C: The History of Planet Earth - Some events happen very quickly; others occur very slowly, over a time period much longer than one can observe (2-ESS1-1). Performance Expectation: 2-LS4-1. Make observations of plants and animals to compare the diversity of life in different habitats. 2-ESS1-1 Use information from several sources to provide evidence that Earth events can occur quickly or slowly.