Introduction to Evolution - Vocabulary Flashcards

Vocabulary-style flashcards covering key evolution concepts from the lecture notes (Pages 1–5).

Charles Darwin

English naturalist who proposed evolution by natural selection and descent with modification; author of On the Origin of Species (1859).

Lamarck

Early evolutionary theorist who proposed inheritance of acquired characteristics and use/disuse of traits in response to the environment.

Buffon (Louis Leclerc, Comte de Buffon)

Naturalist who suggested geographic regions host different plant and animal populations even in similar environments.

Hutton

Geologist who argued that geological features change gradually over time (gradualism).

Continental drift

Hypothesis that Earth’s landmasses have moved over geological time; supported by fossil evidence.

Descent with modification

Darwin’s idea that lineages accumulate changes over time via heritable traits, leading to new species.

Adaptation

Heritable trait or behavior that helps an organism survive and reproduce in its current environment.

Adaptive radiation

Diversification of a single ancestral species into many species adapted to different environments.

Plato’s fixity of species

Idea that living things are static and unchanging.

Fossil evidence

Remains and traces of organisms used to infer extinct species, transitional forms, and past life changes.

Natural selection

Process where individuals with favorable heritable traits reproduce more, passing those traits to offspring.

Overproduction (more offspring)

Producing more offspring than can survive, leading to competition for resources.

Variation

Differences among individuals in heritable traits (e.g., height, metabolism).

Inheritance

Traits are passed from parents to offspring; variation can be inherited.

Can only act on variation

Natural selection acts on existing heritable variation, not on traits that don’t vary.

Survival/reproduction of advantageous traits

Individuals with beneficial traits tend to reproduce at higher rates.

Increase in frequency of beneficial adaptations

Over generations, advantageous traits become more common in a population.

Environmental change and selection

If the environment changes, different traits become advantageous, shifting selection.

Populations evolve, not individuals

Evolutionary change occurs in populations over time, not in single organisms.

Frequency changes of traits

Natural selection alters how common particular traits are within a population.

Artificial selection

Humans consciously select for or against specific traits in organisms.

Divergent evolution

Lineages diverge from a common ancestor into different forms due to different environments.

Convergent evolution

Unrelated lineages evolve similar traits because of similar environments.

Fossil records

Documentation of fossils showing extinction, origin of groups, and transitions over time.

Homology

Similarity in structure or development due to shared ancestry, often with different functions.

Vestigial structures

Organs with reduced or lost original function (e.g., nictitating membrane).

Embryology

Study of embryo and fetal development revealing developmental similarities among species.

Biogeography

Geographic distribution of species and how it shapes evolution and diversification.

Molecular homologies

DNA similarities across species that reflect common ancestry; central dogma links DNA to phenotype.

Central dogma (DNA → RNA → Protein)

Genetic information flows from DNA to RNA to protein, shaping traits and phenotype.

Misconception: evolution is only a theory

In science, a theory is a well-supported explanation; evolution is backed by extensive evidence.

Misconception: individuals evolve

Evolution occurs in populations over generations, not in single individuals.

Misconception: evolution explains origins of life

Evolution explains diversification after life began, not how life originated.

Misconception: organisms evolve on purpose

Evolution has no goal or direction; it is a natural process without intent.

Species

Group of interbreeding individuals that can produce fertile offspring.

Speciation

Process by which one species diverges into two or more species.

Microevolution

Small-scale changes in allele frequencies within a population over time.

Alleles

Different versions of a gene.

Genes

DNA segments that code for specific traits or products.

Gene pool

The total collection of genes and alleles in a population.

Allopatric speciation

Speciation that occurs when populations are geographically isolated.

Vicariance

Geographic barrier splits a population, leading to divergence.

Dispersal

A subset of a population migrates to a new area, promoting divergence.

Sympatric speciation

Speciation that occurs within the same geographic area, often via reproductive isolation.

Habitat differentiation

Populations adapt to different habitats within the same geographic area.

Sexual selection

Evolution driven by mate competition and choice, shaping reproductive traits.

Aneuploidy

Errors in meiosis

Polyploidy

Condition in which a cell or organism has an extra set or sets of chromosomes.

Autoploidy

Individual has two or more complete sets of chreomosomes from its own species.

Reproductive isolation

The existence of biological barriers that impede Téo species from producing viable, fertile, offspring.

Pre-zygotic barriers

Barriers block fertilization occurring between different species.

Temporal isolation

Pre-zygotic, Members of the population mate at different times of the year.

Behavioral Isolation

Pre-zygotic, Differences in courtship rituals

Geographical Isolation

Pre-zygotic, part of population is separated by a geographical element

Mechanical Error

Pre-zygotic, incompatible sex organs

Genetic Isolation

Pre-zygotes, Incompatible sex cells

Post zygotic reproductive barrier

Mechanisms that prevent the formation of viable or fertile offspring after a zygote (fertilized egg) has been formed

Hybrid Viability

Post-zygotic, genes of the different parent species may interact and impair the hybrids development or survival

Hybrid infertility

Post-zygotic, Even if hybrids are fit to survive, may be sterile

Hybrid Breakdown

Post-zygotic, Some first gen hybrids are fertile, but when they mate with another species or with either parent species offspring of the next generation are often feeble or sterile.

Hybrid Zones

Geographical regions where members of different but closely related species mate and produce hybrids.

Gene Flow

Transfer of genetic material from one population to another

Patterns in hybrid zones

Reinforcement, fusion, and stability

Reinforcement

hybrids offspring are less fit than hybrids parentds. Therefore, species continue to diverge until hybridization can’t occur.

Stability

fit hybrids continue to be produced

Fusion

Reproductive barriers weaken until two species become 1

Speciation rate

Gradual special model and punctuated equilibrium model.