Exclusive online articles
Why does Darwinian evolution raise controversy? Explore the library of exclusive online articles below online library below - produced to complement the print issue of 'Big Picture on Evolution' - to find out more about evolution, and consider some of the most profound questions we can ask. Where did we come from? How did life start? Does science enable us to answer these questions?
Darwin's big idea
In the mid-19th century, two natural historians - Charles Darwin and Alfred Russel Wallace - independently arrived at almost identical theories.
Their shared insight was that living species were not fixed, but were the product of change driven by natural selection.
Are humans different?
Can biological mechanisms explain all aspects of human biology or do we need to call upon special processes?
Applying evolution
Evolution by natural selection is such a powerful concept that it is being adopted far and wide.
Memes
Passing cultural information from person to person.
One big family
Everything that lives today, or has ever lived, is the member of the same big family.
Rock stars: The fossil record comes to life
Fossils allow us to glimpse the past. We can trace evolutionary relationships and surmise how life has changed over millions of years.
Close cousins
Chimps are our closest relatives. Genome sequence comparisons are beginning to identify the key genes that distinguish us from them.
Creating variation
Evolutionary change by natural selection (or genetic drift) requires variation in DNA. Where does this variation come from?
Letters begin
Is DNA (or RNA) sequence the only way information can be encoded and passed on from generation to generation? No - 'epigenetic' changes can be inherited too.
Taxing taxonomy
Taxonomy provides a way of characterising living things and documenting family relationships.
Evolution in action
Evolutionary change generally takes place over long time periods.
It is, therefore, rare to see it in progress. More usually, likely time courses of change are inferred, for example from fossil records or analysis of genetic changes.
Occasionally, though, evolution is so rapid we can see it happening before our eyes.
Extinction events
Species die out all the time. Occasionally, though, the Earth experiences mass extinctions.
Directed evolution
For thousands of years humans have tried to harness the best from nature, by modifying crops, animals, or even decorative plants or flowers.
Balancing selection
Natural selection should weed out 'bad' alleles from the gene pool. So why do some still hang around?
Cancer: the selfish cell
The emergence of cancers in the body is a form of natural selection.
Micro- or macro-
Genetic changes create variation. But do they really create new species?
We all stand together
In symbiotic relationships, organisms do not evolve independently but as a pair - or even as a group. Eventually, they may even merge to become a single entity.
Evidence and belief
How many people question the reality of Newton's laws? Or special or general relativity? Quantum theory makes some scarcely believable predictions, such as particles being in two places at the same time.
The evidence satisfies the specialists and that seems to be good enough for the rest of us.
But even though Darwinian evolution faces little or no academic challenge, polls highlight that a significant proportion of people do not accept its principles. Why should this be so?
A lot like us
Humans tend to see things from a human perspective. Does this distort our view of the world?
Life, the universe and everything
Biologists ponder the odds on life emerging on Earth. Physicists find its existence in the universe as perplexing.
The power of prayer
Do religious beliefs provide a selective advantage?
