Descent with Modification and Natural Selection – Evolution Concepts (Vocabulary)

Vocabulary flashcards covering key evolutionary concepts, figures, and terms from the lecture notes.

Descent with Modification

Evolutionary idea that lineages change over time and that descendants differ from their ancestors; introduces history into classification and common descent.

Common Descent

Similar species that arose from a shared ancestor; evolutionarily related groups trace back to a single origin.

Variation

Differences among individuals within a population.

Differential reproduction

Some individuals reproduce more successfully due to advantageous traits, influencing the next generation.

Heredity

The passing of traits from parents to offspring.

Natural Selection

Process by which individuals with favorable traits survive and reproduce more, leading to evolution.

Fitness

An individual’s impact on future generations through survival and reproduction.

Relative Fitness

Fitness compared to others in the population; having more offspring isn’t enough unless it exceeds others’ success.

Absolute Fitness

Total number of offspring an individual produces, regardless of others.

Mutation

A heritable change in DNA that creates new genetic variation (new gene forms).

Alleles

Different forms or variants of a gene.

Mendel's laws of inheritance

Principles (segregation and independent assortment) describing how traits are inherited.

Modern Neo-Darwinian Theory

Aspect of evolution stating: variation is genetic, new gene forms arise by mutation, inheritance follows Mendel, and natural selection acts on this variation.

Lamarck

Jean-Baptiste Lamarck, early naturalist who proposed the inheritance of acquired traits and a mechanism for evolution (later shown incorrect).

Inheritance of Acquired Traits

Idea that traits developed during an organism’s life are passed to offspring; not supported by experimental data.

Weismann

August Weismann, scientist who argued against inheritance of acquired traits and helped establish germ plasm theory.

Beagle

The HMS Beagle, the ship on Darwin’s 1831-1836 voyage that inspired his ideas about evolution.

Darwin

Charles Darwin, naturalist who proposed natural selection as the mechanism of evolution and authored On the Origin of Species.

Alfred Russel Wallace

Naturalist who independently conceived a theory of natural selection similar to Darwin’s; jointly presented ideas in 1858.

On the Origin of Species

Darwin’s 1859 book proposing natural selection as the mechanism of evolution.

Special Creation

Worldview that species were unchanging and uniquely created for their niches; earlier and opposite to evolutionary thinking.

Galapagos Finches

Darwin observed island finches with different beak shapes adapted to local foods, illustrating adaptive radiation.

Adaptive Radiation

Diversification of a lineage into multiple species to exploit different ecological niches, often seen on islands.

Malthus

Thomas Malthus; argued populations grow geometrically while resources grow arithmetically, influencing ideas about competition and struggle for existence.

Evolution

The change in heritable characteristics of biological populations over successive generations.

Prokaryotes

Organisms without a nucleus (e.g., Bacteria and Archaea); simple cell structure.

Eukaryotes

Organisms with a nucleus and complex cell structure (includes protists, plants, fungi, animals).