Biology idea 3: Evolution
Evolution is the process of change in a species that occurs over a long period of time.
The origin of species
Charles Darwin published his book The Origin of in 1859. Darwin’s ideas were not new, but he provided an example of how evolution may occur by a process called natural selection. Darwin’s idea was that a population must have some variability and the individuals best suited for survival continue to breed and increase in numbers.
Darwin’s theory of evolution
Charles Darwin described two key factors that drive evolution: genetic variation and natural selection. Here, David Ackerley of Victoria University, Wellington, discusses Darwin’s theory of evolution.
Bringing together cells, genes and evolution
The genes expressed by a cell determine its function. Genes are packaged up neatly into the nucleus of cells in structures called chromosomes.
The three big ideas – cells, genes and evolution – are intricately linked.
When genes are passed from parents to offspring, some variability may occur. This variability can cause changes in the structure and function of an organism. For example, if an organism inherits an advantageous genetic variation, it is more likely to be successful, to breed and to produce offspring carrying these same genes on to the next generation. This forms the basis of the theory of natural selection.
Darwin's theory of natural selection
Charles Darwin's book on evolution, published in 1859, brought together a huge amount of evidence and – most importantly – suggested a mechanism to explain how evolution might occur.
Cells, genes and evolution
How do the three key biological ideas of cells, genes and natural selection link together?
An inherited idea
Darwin’s grandfather, Erasmus Darwin, was also an advocate of evolution. He was an English doctor with a passionate nature and one of the real characters of science.
Erasmus Darwin, aka lunatic
History has unfolded in a way that we know a lot about Charles Darwin, but his grandfather Erasmus may have led a much more interesting life.
