Biologists’ job involves the study of living organism and their relationship with natural world. They try to discover the mechanism of living creatures with their study of the origin, habits and genetic structure of those organisms. Study of wildlife is an important aspect of a biologist’s job. Methods like identification and observation play a major role in this concern. Various factors of environmental issue that affect wildlife are also important in this context. There are many biologists whose working area is concerned with zoo animals. They work for the preservation of endangered species in a systematic way. Based on their study, they prepare reports that are published in various scientific journals. Biologists working in healthcare sector work to prevent deadly diseases by identifying harmful virus. There are many biologists who serve in environmental management and conservation field. Their work involves providing solution for environmental problems and preservation of nature. Marine biologists conduct study on animals and plants that live in salt water. Biologists working in educational sector engage themselves in the publication of their study in different journals besides imparting education at classrooms. What follows is a collection of the biographies, timelines and trivia about some of the world’s most famous biologists.