The Origin of Species · Chapter
Convergence of Character explained
Darwin addresses the concept of convergence, where distinct species might evolve to resemble each other, but argues that such close convergence is unlikely due to the complex interplay of variation, selection, inheritance, and competition.
What happens
Darwin addresses the concept of convergence, where distinct species might evolve to resemble each other, but argues that such close convergence is unlikely due to the complex interplay of variation, selection, inheritance, and competition. He also discusses factors that limit the indefinite increase of species, including physical conditions, competition, rarity, and the spread of dominant species.
Free preview opens on this chapter — companions, themes, and character notes appear beside the text.
Narrative arc
Story tension across the book — this chapter sits in Exposition.
- Setup
- Escalation
- Breaking point
- Aftermath
- Closing
This passage marks the story's dramatic climax because Darwin shifts from a defensive posture against objectio…
Full beat labels and climax notes unlock in the reader.
Follow the arc while readingThemes in this chapter
- Natural Selection and the Struggle for Existence
Darwin discusses how natural selection, competition, and the spread of dominant species limit the indefinite increase of species.
- Geographical Distribution and Barriers
The spread of species and the impact of invaders on endemic species in Australia illustrate geographical distribution dynamics.
Characters to notice
- Mr. H. C. Watson
Watson thinks Darwin overrated divergence of character and believes convergence has played a part.
- De Candolle
Alph. de Candolle showed that widely spreading species tend to spread very widely, supplanting others.
- Dr. Hooker
Hooker recently showed that in southeast Australia, invasive species have reduced endemic Australian species.
Key passages
“If two species belonging to two distinct though allied genera, had both produced a large number of new and divergent forms, it is conceivable that these might approach each other so closely that they would have all to be classed under the same genus; and thus the descendants of two distinct genera would converge into one.”
If two species from different but related genera each gave rise to many new forms, those forms might become so similar that they would be grouped into a single genus, causing the descendants of two separate genera to converge.
Darwin explains the theoretical possibility of convergence between distinct lineages.
“It is incredible that the descendants of two organisms, which had originally differed in a marked manner, should ever afterwards converge so closely as to lead to a near approach to identity throughout their whole organisation.”
It is highly unlikely that the descendants of two very different organisms would ever become nearly identical in their entire structure through convergence.
Darwin expresses skepticism about extreme convergence leading to near-identical forms.
“When any species becomes very rare, close interbreeding will help to exterminate it; authors have thought that this comes into play in accounting for the deterioration of the aurochs in Lithuania, of red deer in Scotland and of bears in Norway, etc.”
When a species becomes very rare, inbreeding can contribute to its extinction, as some authors believe happened with the aurochs in Lithuania, red deer in Scotland, and bears in Norway.
Darwin notes that rarity and inbreeding can accelerate extinction.
