On the Origin of Species by Charles Darwin - Key Concepts

Flashcards covering the key concepts, definitions, and ideas from Charles Darwin's 'On the Origin of Species'.

What main source of variation does Darwin emphasize in Chapter 1?

Inherited traits, not acquired ones.

What model does Darwin use to illustrate evolution in Chapter 1?

Artificial selection.

What does Darwin argue is more important for evolution: rare abrupt changes or small consistent variations?

Small consistent variations.

Which theory of heredity does Darwin dispute in Chapter 1?

Lamarck's idea that acquired traits are inherited.

What does Darwin compare to set the stage for natural selection?

Artificial selection.

In Chapter 2, what does Darwin emphasize about individuals within the same species in nature?

They show natural variation.

What is the significance of small differences according to Darwin in Chapter 2?

They provide the raw material for natural selection.

What does Darwin suggest about the relationship between species and varieties?

The line is often blurry and experts may disagree on definitions.

What does Darwin propose is the origin of all species and varieties?

A common ancestor.

What factor does Darwin connect to natural selection in Chapter 3?

The struggle for existence.

What theory does Darwin reference regarding population growth?

Malthus's theory that resources are limited.

What drives the intensity of competition in nature?

Similar species or individuals occupying the same niche.

What are beneficial traits expected to do according to Darwin?

Help individuals survive and reproduce.

What concept does Darwin introduce that refers to the interconnectedness of organisms?

Ecological interdependence.

What is the definition of natural selection according to Chapter 4?

Individuals with favorable traits survive and reproduce more successfully.

What occurs due to the divergence of character?

Small variations can accumulate and lead to new species.

How does geographical isolation affect populations?

It prevents gene flow and leads to unique traits evolving in isolated groups.

What concept refers to gradual evolutionary changes over long timescales?

Gradualism.

What happens to species with less favorable traits in an evolutionary context?

They may go extinct.

What role does ecological niche play in the survival of species?

It reduces competition and increases survival chances.

What does Darwin argue about causes of variation in Chapter 5?

They are shaped by conditions of life over generations.

How can the use and disuse of organs affect traits?

Changes can occur depending on how often organs are used, and these changes can be inherited.

What does Darwin mean by acclimatization?

Species can adapt to new environments but with caution not to overstate its effects.

What is the difference between rudimentary and specialized structures?

Rudimentary structures vary more, while specialized ones vary less due to natural selection.

What does Darwin say about old ancestral traits?

They can reappear unexpectedly, a process known as reversion.

What major difficulty in Darwin's theory does he address regarding transitional forms?

The fossil record is often incomplete.

How do partially formed organs contribute to evolution, according to Darwin?

They can still provide survival advantages, allowing gradual evolution.

What explains the existence of distinct species in the fossil record?

Intermediate forms may be outcompeted and go extinct, leaving successful species.

What can limit gene flow and lead to independent evolution according to Darwin?

Geological isolation.

How does Darwin address the evolution of complex instincts in Chapter 7?

He argues they developed gradually through small improvements that offered advantages.

What is the significance of intermediate stages in evolution according to Darwin?

Even minor advantages can help an organism survive and reproduce.

What does Darwin suggest about seemingly useless traits?

They may be leftovers from ancestral adaptations or by-products of other useful traits.

How do instincts compare to habits?

Instincts are inherited and automatic, while habits are learned.

What does Darwin observe about hybridization in Chapter 9?

Crosses between different species usually result in sterile offspring.

What supports Darwin’s idea regarding varieties?

Varieties usually have no fertility issues when crossed.

What can lead to increased sterility over time between two groups?

Divergence over time.

What is the effect of natural selection on hybridization?

Natural selection discourages hybrid mating to maintain species boundaries.

What does Darwin suggest about the geological record?

It is incomplete, with many transitional forms missing due to fossilization conditions.

What do geological studies support regarding species evolution?

New species appear gradually over time.

What does Darwin mean by geographical succession?

New species often arise in the same areas as their ancestors.

How does climate influence species distribution?

Past climate events helped species migrate, affecting biodiversity.