Unit 1 Evolution: Week 2 — Evidence for Evolution (Video Notes)

Vocabulary flashcards covering key terms from the lecture notes on evolution, natural selection, fossils, anatomy, and biogeography.

Natural Selection

The differential survival and reproduction of individuals due to heritable variation, leading to changes in trait frequencies over generations.

Phenotypic Variation

Observable differences in traits among individuals, which may be heritable.

Heritability

The extent to which variation in a trait is due to genetic factors and can be passed to offspring.

Differential Reproductive Success

Individuals with certain traits leave more offspring than others, shifting trait frequencies.

Adaptation

A heritable trait that increases an organism’s fitness in a given environment.

Artificial Selection

Human-caused selection that favors certain traits, guiding evolutionary change.

Industrial Melanism

Increase in frequency of dark-colored forms in polluted environments due to selection.

Peppered Moth

Biston betularia; a moth species used as a classic example of industrial melanism.

Beak Depth

A measure of beak size depth, related to diet and survival under different seed availability.

Beak Morphology

Shape and size characteristics of a beak that influence foraging.

Daphne Major (Grant Study)

Long-term study of Darwin’s finches showing beak-depth changes in response to environmental shifts.

Fossil

Preserved remains or traces of once-living organisms found in rock.

Fossilization

Process by which organisms become fossils: burial, mineralization, and rock formation.

Isotopic Dating

Dating rocks by measuring radioactive isotopes to determine absolute ages.

Absolute Dating

Determining the exact numerical age of rocks or fossils using isotopes.

Potassium-40 (40K)

Radioactive potassium isotope with a long half-life (~1.25 billion years) used for dating ancient rocks.

Radiocarbon Dating (Carbon-14)

Dating method using 14C with a half-life of ~5700 years; used for recent organic material.

Fossil Record

The chronological collection of fossils documenting evolutionary changes.

Homologous Structures

Structures in different species with the same ancestry, possibly different functions.

Forelimb Homology

Homologous forelimb structures across mammals showing a common bone plan.

Comparative Embryology

Study of embryonic development across species revealing evolutionary relationships.

Pharyngeal Pouches

Embryonic features that develop into glands/ducts in humans or gill slits in fish.

Vestigial Structures

Remnants of features that had function in ancestors but are reduced or useless now.

Pseudogenes

Nonfunctional gene remnants that resemble ancestral functional genes.

Biogeography

Study of the geographic distribution of species and their historical causes.

Convergent Evolution

Independent evolution of similar traits in different lineages due to similar selective pressures.

Niche

The role and position of a species within its environment, including resources and interactions.

Australian Marsupials vs Placental Mammals

Example of convergent outcomes; similar forms arise in different lineages due to similar environments.

Domestication

Human-imposed selection leading to domesticated varieties through breeding.

Agricultural Selection

Selective breeding in crops and livestock to enhance desirable agricultural traits.

Pleiotropy

One gene influencing multiple phenotypic traits.

Linkage

Genes located near each other on a chromosome tend to be inherited together.

Imperfect Adaptation

Traits that work but are not optimal, due to constraints and historical paths.

Comparative Anatomy

Study of anatomical similarities and differences to infer evolutionary relationships.

Homology vs Analogy

Homology = similarity due to common ancestry; analogy = similarity due to convergent evolution.