In it, Darwin proposed that the features of all living things, including humans, were shaped by natural processes of descent with accumulated modification leading to divergence over long periods of time.
Ian Wilmut led a research group that in 1996 first cloned a mammal from an adult somatic cell, a Finnish Dorset lamb named Dolly.
Students who aspire to a research-oriented career usually pursue a graduate degree such as a master's or a doctorate (e.g., PhD) whereby they would receive training from a research head based on an apprenticeship model that has been in existence since the 1800s.
Swift advances in knowledge of genetics and organic molecules spurred growth in the field of biotechnology, transforming the industries in which biological scientists work.
Biological scientists can now manipulate the genetic material of animals and plants, attempting to make organisms (including humans) more productive or resistant to disease.
Basic and applied research on biotechnological processes, such as recombining DNA, has led to the production of important substances, including human insulin and growth hormone.
This work continues to lead to the discovery of genes associated with specific diseases and inherited health risks, such as sickle cell anemia.
Most biological scientists specialize in the study of a certain type of organism or in a specific activity, although recent advances have blurred some traditional classifications.[why?]
Although some marine biologists obtain their specimens from the sea, many still spend a good deal of their time in laboratories and offices, conducting tests, running experiments, recording results, and compiling data.
Many biological scientists, such as botanists, ecologists, and zoologists, conduct field studies that involve strenuous physical activity and primitive living conditions.