# The Probable Effects of the Action of Natural Selection Through Divergence of Character and Extinction, on the Descendants of a Common Ancestor explained — The Origin of Species

> Chapter companion for The Origin of Species by Charles Darwin.

## What happens

Darwin explains how natural selection, divergence of character, and extinction work together to produce new species from a common ancestor. Using a diagram, he illustrates how widely-diffused and variable species give rise to divergent varieties over many generations, with the most divergent forms being preserved. He emphasizes that extinction eliminates intermediate and less improved forms, leading to greater differentiation among surviving species, and that the process results in the multiplication of species and formation of genera.

## Themes in this chapter

### Natural Selection and the Struggle for Existence

Natural selection acts by preserving profitable variations, with competition most severe between closely related forms.

### Extinction and the Succession of Forms

Extinction eliminates intermediate and less improved forms, allowing more divergent descendants to prevail.

### Common Descent and the Tree of Life

All species in the diagram descend from a common ancestor, with branching lines representing divergence over generations.

## Character check-ins

### Charles Darwin

Author presenting the theoretical model of divergence and extinction.

## Key lines

> the competition will generally be most severe between those forms which are most nearly related to each other in habits, constitution and structure.

Competition is strongest among closely related organisms because they share similar needs and traits.

_Explains why extinction often removes intermediate forms._

> the more diversified in structure the descendants from any one species can be rendered, the more places they will be enabled to seize on, and the more their modified progeny will increase.

Greater diversity among descendants allows them to occupy more ecological niches and thus increase in number.

_Key principle of divergence of character._

## Links

- HTML: https://www.betterreads.online/discover/the_origin_of_species_se/chapters/the-probable-effects-of-the-action-of-natural-selection-through-divergence-of-character-and-extinction-on-the-descendants-of-a-common-ancestor
- Book: https://www.betterreads.online/discover/the_origin_of_species_se
- All chapters: https://www.betterreads.online/discover/the_origin_of_species_se/chapters