Evolution and Speciation: Key Concepts in Biology

James Hutton

gradualism and father of geology

Charles Lyell

Uniformitarianism - laws acting on Earth over time remain the same over time

What concept did Jean-Baptiste Lamarck propose regarding evolution?

The inheritance of acquired traits and the idea that organisms adapt to their environment.

Lamarck's idea of change

He was the first to argue that species are not fixed and can adapt to their environment.

What did Thomas Malthus contribute to Darwin's theory of natural selection?

He noted that populations grow geometrically while resources grow arithmetically, leading to competition and struggle.

What is the foundation of Darwin's theory of natural selection?

Not all individuals survive; those with advantageous traits reproduce more successfully.

What evidence supports the unity of life?

Common ancestry, universal genetic code, shared metabolic pathways, and homologous genes.

What explains the diversity of life according to evolutionary theory?

Mutation introduces new variations, natural selection filters these variations, and genetic drift causes random changes.

What does the fossil record demonstrate about evolution?

It shows chronological change and includes transitional fossils like Tiktaalik.

homologous structures

Structures with the same embryological origin but different functions, indicating divergent evolution.

analogous structures

Structures with the same function but different origins, indicating convergent evolution.

vestigial structures

Reduced or nonfunctional structures, such as the pelvis in whales, indicating evolutionary history.

What type of evidence is considered most reliable on AP exams?

Molecular evidence, including DNA sequence similarity and protein homology.

What is the Hardy-Weinberg equation used for?

To predict genotype frequencies in a population if no evolution is occurring.

List the five conditions for Hardy-Weinberg equilibrium.

No mutation, random mating, no natural selection, large population, no gene flow.

What is allopatric speciation?

Speciation that occurs due to geographic isolation, leading to divergence.

What is sympatric speciation?

Speciation that occurs without physical barriers, often due to polyploidy or habitat differentiation.

What are prezygotic barriers in reproductive isolation?

Mechanisms that prevent mating or fertilization, such as habitat isolation and temporal isolation.

What are postzygotic barriers in reproductive isolation?

Mechanisms that occur after fertilization, such as hybrid inviability and hybrid sterility.

What is adaptive radiation?

Rapid diversification of species when they adapt to new environments or after mass extinctions.

What is the difference between gradualism and punctuated equilibrium?

Gradualism is slow, steady change, while punctuated equilibrium involves rapid bursts of change followed by long stability.

What is the significance of the statement 'individuals do not evolve, populations do'?

Evolution refers to changes in allele frequencies within populations over time.

What is the main takeaway regarding natural selection?

Natural selection is a mechanism of evolution, not a goal-driven process.

What does the term 'fitness' refer to in evolutionary biology?

The ability of an individual to survive and reproduce in its environment.

What is the role of mutation in evolution?

Mutation introduces new genetic variations that can be acted upon by natural selection.

Lamarck

French naturalist who proposed that evolution resulted from the inheritance of acquired characteristics (1744-1829)

temporal speciation

mating occurs in different time periods

gametic speciation

Sympatric speciation

genetic or chemical incompatibility

behavioral speciation

Behavior differences stop groups from mating and leads to two new species

mechanical speciation

anatomical incompatibility between body parts or in pollinators

ecological speciation

the evolution of reproductive barriers between populations by adaptation to different environments or ecological niches

geographical speciation

Evolution of two or more species from a single species following geographic isolation.

Inviability

hybrid does not develop into maturity

Reduced vigor

Lower levels of sexual activity

Infertility

Cannot reproduce

Breakdown

1st generation ok, 2nd fails