History of Evolutionary Thought and Principles

Vocabulary flashcards covering early concepts of nature, historical figures in evolutionary biology, theories of Earth's history, and mechanisms of evolution.

Scala Naturae

Also known as the 'Scale of Nature'; a staircase of complexity created by Aristotle.

Species Fixity

The belief, associated with Aristotle, that all species came from gods.

Natural Theology

Taking things from nature and giving them a reason to have been created.

Fossils

Remanents of past life that came way before humans; typically found in sedimentary rock (layers that show Earth's age).

Taxonomy

The meaning and naming of organisms; created by Carolus Linnaeus.

Theory of Gradualism

Proposed by James Hutton; the concept that changes that happen are slow and occur over time rather than suddenly.

Paleontology

The study of past lives; created by George Cuvier.

Theory of Uniformitarianism

Proposed by Charles Lyell; the idea that things we see today have also been seen in the past.

Jean Baptiste Lamarck

The first person to put his idea of species changing over time into the public; proposed that inheritance of acquired traits was how species changed.

Inheritance of Acquired Traits

The mechanism by which Jean Baptiste Lamarck thought species changed over time.

Speciation

The formation of a species through changing, adapting, and evolving.

Charles Darwin

Scientist who stated that evolution occurs at the level of population and posted a book on his research in 1859.

Artificial Selection

The process where humans take natural variation and manipulate it to our desires based on traits.

Natural Selection

The process where nature selects based on traits that are best fit for the environment, allowing the species to persist.

Aspects of Natural Selection

Variation, Heritability, Competition, Differential Fitness

Homology / Homologous Traits

Traits shared by different species through ancestry

5 Sub Theories

1. Perpetual Change

2. Gradualism

3. Common Descent

4. Speciation

5. Natural Selection

Differential Fitness

The variation in survival and reproduction among individuals within a population

Adaptation

The process of evolutionary modification that results in improved survival and reproduction

Evolution occurs at what level?

Population

Natural selection acts upon?

Individuals

Genes

Discrete units of inheritance

Genotype

Genetic makeup of an organism

Phenotype

Physical of physiological manifestation of the genotype

Alleles

Variants of the same gene

Population

Smallest unit of evolution

Modern Synthesis

Recognizes there is a genetic component in traits

Allele Types

Dominant and recessive

Sources of Genetic Variation

1. Mutations - original source of variation

2. Recombinations - sexual reproduction

Micro evolution

Changes the genetic variation of a population over time

Polymorphism

A character within a population represented in 2+ forms

Genetic Variation

Occurs in separate groups of the same species living in geographic regions

Population Genetics

Studying genetic variation within populations and the process acting on them

Allele Frequencies

Proportion of a populations gene pool of specific alleles

Conditions needed for Hardy Weinberg equilibrium

1. No mutation

2. Infinite pop. Size

3. No gene flow

4. No natural selection

5. Random mating

Evolutionary Mecahnisms

1. Mutations

2. Genetic Drift

3. Genetic Flow

4. Natural Selection

5. Non-random Mating

Homogenization

Decrease in genetic differetiation in a population

Intrasexual Selection

Same sex individuals compete for a mate

Intersexual Selection

One sex picks individuals of the opposite sex

Sampling Error

Rule of probability; greater deviation will occur more often in small samples

Fixation

One allele becoming prevalent until its the only one over time

Founder Effect

Small sample of larger population becomes a new population

Fitness

Contribution of a phenotype to subsequent generations relative to other phenotypes

Gene Pool

A collection of genetic material shared by all members of a population

Bottleneck Event

A drastic reduction in population size that can lead to reduced genetic diversity

Gene Flow

Genetic exchange between populations due to the movement of individuals

Geographic Variation

Variation of a trait amongst populations of the same species

Heterozygote Advantage

When the heterozygote is better suited for the population

Biological Species Concept

Biological aspects used t distinguish between species

Behavioral Isolation

Two species rarely interact due to their behaviors regarding reproduction

Types of reproductive isolation

Prezygotic and postzygotic

Allopatric Speciation

Geographic isolation occurring between 2 or more populations (most common)

Sympatric Speciation

The population becomes reproductively isolated

Polyploidy

Extra sets of chromosomes

Adaptive Raditation

Happens through new habitats or after a mass extinction event

Hybridization

2 species interbreeding / incomplete reproductive isolation

Reinforcement

The strengthening of prezygotic barriers between species.

Hybrid Zones

Areas of overlap between two species where there is incomplete reproductive isolation.

Hybrid Infertility

The postzygotic isolation mechanism that a mule represents

In order for a taxonomic grouping to be considered correct it must be-

Monophyletic

Taxonomic Classifications

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

Infers evolutionary evolution

Phylogenies

Rock that contains fossils

Sedimentary

Traits through common ancestry

Homologous traits

Traits through shared environments

Analogous Traits

Linnean convention of assigning a two part Latinized name to an organism

Binomial Nomenclature

Similar characteristics evolving independently among distantly related organisms

Convergent Evolution

Clade

A group of species that share an ancestors

Outgroup

Any group in a study not in a taxon

Parsimony

The most likely answer is the easiest to get

Radiometric Dating

Radioactive isotope used to determine how old something is

Half Life

Member of years it takes for 50% of original amount of radioisotope to decay

Seafloor Spreading

The process by which tectonic plates move

Divergent Plate Boundries

New crust is formed and plates are pushed apart