Evolution and Natural Selection Quiz

Adaptation vs. Variation

• Adaptations help organisms survive and reproduce in a particular ecosystem
• Variations are differences between individuals, which can be structural, functional, or physiological

Types of Adaptations

• Structural Adaptations: Physical features enabling survival in an environment.
• Physiological Adaptations: Internal or cellular features enabling survival in an environment. Examples include hibernation to reduce metabolism and venom production for defense or hunting.
• Behavioral Adaptations: Actions enabling survival in their environment. Examples include migration for food or favorable weather, or group traveling for protection against predators.

Camouflage and Mimicry

• Camouflage: Organisms blending in with their environment, increasing their chances of survival. Examples include stick insects.
• Mimicry: Harmless species resembling harmful ones in color or structure, deterring predators. Examples include the monarch and viceroy butterfly.

English Peppered Moth

• Example of adaptation to environmental change.
• Colour variations: greyish-white with black spots (flecked), and black (melanic).
• Nocturnal, resting in trees during the day.
• Prey for birds.

Industrial Revolution and Peppered Moths

• Before the Industrial Revolution, light-colored lichens covered trees, providing camouflage for the light-colored moths.
• Darker-colored moths were less common (2% of the population).
• During the Industrial Revolution, air pollution killed lichens and trees became dark, increasing the visibility of light-colored moths.
• Dark-colored moths had a selective advantage, becoming more common (95% of the population by 1889).
• After pollution reduction, lighter-colored moths increased, because the trees became light again.

Variation Within Species Arises From Genes

• Genetic variations allow for a large number of possible gene combinations.
• This ultimately leads to differing genetic variations of individuals within a population.

Mutation & Selective Advantage

• Mutations are permanent changes in DNA, the source of new variation.
• Mutations can be random and occur in somatic (body) cells and gamete cells.
• Mutations can be caused by UV radiation, viruses, or exposure to chemicals.
• Only mutations in gamete cells can be passed to offspring giving a potential selective advantage.

Selective Pressure

• Environmental factors (abiotic and biotic factors) determine whether traits are suitable for survival.
• Useful traits are selected for; those not are selected against. Examples: light, water, temperature, soil, food, mates, habitat, parasites etc.

Selective Advantage

• A genetic advantage that improves an organism's chance of survival and reproduction under changing environmental conditions.

Process of Natural Selection

• The traits in a population change over many generations through organisms with advantageous traits surviving and reproducing.

Natural Selection

• No purpose or direction (situational); beneficial traits in one environment may not be so in another.
• Adaptations are a result of natural selection acting on populations (who are better adapted in a specific environment) to improve their survival and reproduction.

Genetic Variability

• Diversity within a species (e.g., peppered moths, antibiotic resistance).

Heritability

• Traits passed on to offspring.

Selective Pressure

• Environmental conditions that favor or disfavor certain traits.

Artificial Selection

• Selective pressure exerted by humans to improve or modify particular traits in populations (e.g., domesticated plants and animals).

Comte de Buffon/Leclerc

• Early naturalist who implied that species change over time.

Anning

• Fossil hunter who uncovered important fossils, especially plesiosaurs.

Cuvier

• Founder of paleontology who discovered that each rock layer has unique fossil species, and came up with Catastrophism.

Lyell

• Proposed uniformitarianism: Earth's surface changes gradually over time.

Lamarck

• Proposed the Theory of Acquired Characteristics: traits acquired during an organism's lifetime can be passed down. Examples include increased muscle mass or giraffes stretching their necks. However, this theory is incorrect.

Darwin's Theory of Evolution by Natural Selection

• Publication in 1859.
• Organisms produce more offspring than can survive.
• Individuals vary, and much variation is heritable.
• Individuals better suited to local conditions survive to reproduce.
• Change is slow and gradual.
• Example: English peppered moth.

Evidence for Evolution

• Fossil Record: Fossils in older layers are different from modern species.
• Biogeography: Geographic distribution of species provides evidence of common ancestry.
• Comparative Anatomy: Homologous (similar structure, different functions) and analogous structures (different structure, similar functions) provide links between species.
• Embryology: Similar embryonic development suggests common ancestry.
• Molecular Biology: Similar DNA sequences in closely related species.

Macroevolution vs. Microevolution

• Macroevolution: Large-scale evolutionary changes, like the emergence of new species.
• Microevolution: Small-scale changes in gene frequencies within a population.

Mutations

• A change in DNA that can be random (mutations) or caused by environmental factors.

Gene Flow

• The movement of genes between populations, which alters allele frequencies in those populations.

Genetic Drift

• Random changes in allele frequencies, especially prominent in small populations.

Bottleneck Effect

• A significant reduction in population size due to environmental events, potentially altering allele frequencies.

Founder Effect

• A new population started by a small group of individuals from a larger population. The allele frequency of these individuals can differ significantly from the original population.

Non-Random Mating

• Mating partners not chosen at random, but based on phenotypic traits or relatedness. This includes inbreeding.

Types of Natural Selection

• Stabilizing selection: Extreme phenotypes are selected against, and moderate traits favoured.
• Directional selection: One extreme phenotype is favoured over the other.
• Disruptive selection: Both extreme phenotypes are favoured over the moderate phenotypes.
• Sexual selection: Traits that increase mating success, even if not directly related to survival.

Speciation

• The process by which new species originate.
• Reproductive isolation is key to speciation -- populations must be reproductively isolated from each other so that gene flow between them ceases.
• Allopatric speciation: Speciation that occurs when populations are geographically separated.
• Sympatric speciation: Speciation that occurs within a single population

Divergent Evolution

• Evolutionary change that produces traits that are dissimilar, as a response to differing environmental stimuli.
• Results from adaptive divergence; dissimilar adaptations/traits in different species because they are adapted to different environmental conditions.

Convergent Evolution

• Evolutionary changes produce traits that are similar in unrelated species.
• Results from analogous structures. Similar traits/adaptations in different species because they are adapted to similar environmental conditions.

Types of Speciation

• Allopatric: Geographic isolation
• Sympatric: Not geographically isolated; different breeding behaviours, or other characteristics cause reproductive isolation.

Test your knowledge on the evolution of the English Peppered Moth and the impact of the Industrial Revolution on its population. This quiz covers concepts such as genetic variation, survival of the fittest, and the definitions related to Darwin's theories. Perfect for students studying biology or evolution.