Cell theory
From RationalWiki
Cell theory is the theory in biology that cells form the foundation, the basic unit of all living organisms. All organisms that have been recognized as alive are composed of cells, although viruses are somewhat of a grey area and any evolutionary precursor to the cell would obviously not be a cell.
[edit] Another "theory"
Despite cells having been observed with various microscopes for a century, it is still considered a theory. Just like the theory that the earth moves around the sun, that gravity pulls things to other things and that the diversity of life is explained by natural selection.
The origin of the theory comes from observations as early as the 17th century of the cell-like appearance of organisms close up. Cell theory has since evolved and altered as evidence and technology has allowed scientists to look closer at them, starting at first to identify large systems such as the nucleus and cell wall, and moving into smaller sections with larger names such as the endoplasmic reticulum or the mitochodria.
[edit] The complexity of the cell
As was mentioned to great anticlimax in the film Expelled: No Intelligence Allowed, in Charles Darwin's time, the cell was thought to be simple, but now it is considered to be a vast and complex machine. However, this incorrectly assumes that the nature of the cell has a direct bearing on how evolution by natural selection works, which is simply not the case. Just as if evolutionary theory was thrown out completely, the complexity of the cell and cell theory would remain unchanged, the changing knowledge of the cell's complexity has no effect on evolution and natural selection. Indeed, a claim such as Ben Stein's in the movie and his promotional interviews would be akin to saying that Newton's theories of gravitation and Newtonian mechanics are wrong because Newton had no clue as to the structure of the atom and its place in the formation of the materials affected by his laws of motion.
