Evolutionary dating flaws
and replicate by creating multiple copies of themselves through self-assembly.However, viruses do not metabolize and they require a host cell to make new products.
Throughout history, there have been many attempts to define what is meant by "life" and many theories on the properties and emergence of living things, such as materialism, the belief that everything is made out of matter and that life is merely a complex form of it; hylomorphism, the belief that all things are a combination of matter and form, and the form of a living thing is its soul; spontaneous generation, the belief that life repeatedly emerges from non-life; and vitalism, a now largely discredited hypothesis that living organisms possess a "life force" or "vital spark".
Artificial life is a computer simulation or man-made reconstruction of any aspect of life, which is often used to examine systems related to natural life.
Death is the permanent termination of all biological functions which sustain an organism, and as such, is the end of its life.
Some microorganisms, called extremophiles, thrive in physically or geochemically extreme environments that are detrimental to most other life on Earth.
Aristotle was the first person to classify organisms.
One systemic definition of life is that living things are self-organizing and autopoietic (self-producing).