Systematics & Taxonomy, Origin of Species, Origin of Life

Vocabulary flashcards based on lecture notes on Systematics, Taxonomy, Origin of Species, and Origin of Life.

Taxonomy

Science dealing with the description, classification, identification, and nomenclature of extinct and extant organisms and viruses.

Carolus Linnaeus

Father of Modern Taxonomy; published a system of taxonomy based on resemblances.

Binomial nomenclature

Two-part scientific name of a species (genus and specific epithet).

Hierarchical classification

System of classifying organisms into groups within groups, based on shared characteristics; 7 taxa/ranks/categories.

Systematics

Science dealing with the taxonomy of biological diversity and the determination of their phylogenetic or evolutionary relationships.

Domain

The highest taxonomic level; introduced by Carl Woese.

Genus

The first part of a binomial name.

Specific epithet

The second part of a binomial name; unique for each species within the genus.

International Codes of Nomenclature

Rules for naming organisms, established and regulated by international organizations of taxonomists.

International Code of Nomenclature of Prokaryotes (ICNP)

Applies to all Prokaryotes.

International Code of Nomenclature for Algae, Fungi, and Plants (ICN)

Nomenclature of algae, fungi, and plants is independent of zoological and prokaryotic nomenclature.

International Code of Zoological Nomenclature (ICZN)

System of scientific names applied to taxonomic units of extant or extinct animals.

International Code of Virus Classification and Nomenclature (ICTV)

Classification and nomenclature of virus taxa.

International Code of Nomenclature for Cultivated Plants (ICNCP)

Nomenclature for cultivated plants.

Phylogeny

The evolutionary history of a species or group of organisms.

Apomorphy

Represents evolutionary change; derived state.

Phylogenetic tree (cladogram)

A branching diagram showing the evolutionary history of a group of organisms.

Branch point

Where lineages diverge on a phylogenetic tree.

Sister taxa

Groups that share an immediate common ancestor.

Rooted tree

Includes a branch to represent the last common ancestor of all taxa in the tree.

Basal taxon

Diverges early in the history of a group and originates near the common ancestor of the group.

Polytomy

A branch from which more than two groups emerge.

Plesiomorphy

Pre-existing feature; ancestral feature

Symplesiomorphy

Shared ancestral feature

Synapomorphy

Shared derived feature.

Clade

A group of species that includes a common ancestor and all its descendants.

Cladistics

The analysis of how species may be grouped into clades.

Monophyletic clade

Consists of a common ancestor and all of its descendants.

Paraphyletic clade

Consists of an ancestor and some, but not all, of its descendants.

Polyphyletic clade

Consists of various species with different ancestors; lacks a common ancestor.

Homology

Shared characteristics derived from one ancestor.

Ingroup

Species for which you want to make a cladogram.

Outgroup

A species that is closely related to the species under study; has a shared primitive character common to all species.

Morphological and molecular data

Genes and biochemistry of living organisms and fossil records.

Analogy

Similarity due to convergent evolution.

Can be grouped by apomorphies because they represent unique evolutionary events.

Taxa / Operational Taxonomic Units (OTU)

Classical/Artificial Classification

Based on few observable characters e.g. Linnaeus Sexual System and Theophrastus form system of plant.

Plant Classification Systems

Classical/Artificial, Phenetics/Natural, Cladistics/Phylogenetic

Phylogeny

The evolutionary history of species or group of organisms.

Theophrastus System

Made use of plant habits.

Linnaean System

Made use of characters that describes stamens (e.g. number, position) as basis to establish the 20+ classes of the plants.

Phenetics/Natural Classification

Constructs phenograms based on overall similarity, largely phenotypic, without regard to evolutionary history.

Charles Bessey

Proposed the Phylogenetic Taxonomy of Flowering Plants.

Estimate ranges from 3.6-111 million species. Normally used working figure is often 10-15 million

HOW MANY SPECIES ARE THERE?

Theory of forms

Began by Plato; Perfect vs Imperfect forms (variations are imperfections)

Aristotle

He reinforced theory of times(species reflect existence of unchanging, ideal form, the “universal” or "type".

St. Augustine

"In the beginning were created only germs or causes of forms of life which were afterwards to be developed in gradual course.”

Species

Latin for 'kind' or 'appearance'; organisms belonging to the same kind.

Species fixity

Concept that each species remains unchanged since its creation.

Typological Species Concept

A species is a set of organisms that resemble one another and is distinct from other sets.

Modern species problem

A problem of competing species concepts.

Biological Species Concept

Species as a group of actually or potentially interbreeding natural populations which are reproductively isolated from other such groups.

Reproductive isolation

Populations whose members do not mate with each other or who cannot produce fertile offspring.

Geographic isolation

Species separated by physical barriers.

Behavioral isolation

Species differ in their mating rituals.

Temporal isolation

Species reproduce in different seasons or at different times of the day.

Mechanical isolation

Structural differences between species prevents mating.

Gamete fusion prevention

Gametes of one species function poorly with the gametes of another species.

Postzygotic isolation

Prevents normal development into reproducing adults.

Hybridization

Mating between two different species with a zygote being formed.

Paleontological species concept

Focuses on morphologically discrete species known only from the fossil record.

Phylogenetic species concept

Defines a species as a set of organisms with a unique genetic history that is as one branch on the tree of life.

Ecological species concept

Views a species in terms of its ecological niche, its role in a biological community.

Speciation

The process by which new species arise, either by transformation or splitting.

Anagenesis

Transformation of one species into another.

Cladogenesis

Splitting of one ancestral species into two descendant species.

Autopolyploidy

Arises from genome duplication; meiotic non-reduction of gametes.

Allopolyploidy

Arises from hybridization plus genome duplication; homeologous pairing is predominant.

Allopatric speciation

Speciation that takes place in populations with geographically separate ranges.

Sympatric speciation

Speciation that takes place in geographically overlapping populations.

Panspermia

Life exists throughout the universe distributed by space dust, meteoroids, asteroids, comets, planetoids, and also by contaminated spacecraft.

Spontaneous Generation Theory (Abiogenesis)

Life can arise from nonliving matter.

Biogenesis

Life arises from pre-existing life.

Oparin-Haldane hypothesis

Life arose gradually from inorganic molecules, with 'building blocks' like amino acids forming first and then combining to make complex polymers.

Miller-Urey experiment

Abiotic synthesis of organic molecules in a reducing atmosphere is possible. Amino acids were formed spontaneously.

Chemosynthesis

Biological production of organic compounds from C-1 compounds and nutrients, using the energy generated by oxidation of inorganic or C-1 organic molecules.

Protocells

Vesicles exhibit simple reproduction and metabolism and maintain an internal chemical environment.

LUCA

Last unknown common ancestor; protocells/prokaryotes that gave rise to the Bacteria and Archaeans.

Endosymbiosis

Eukaryotes evolved from the fusion of Bacteria and Archaea.

Three Domains of Life

Bacteria, Archaea, and Eukarya.

Geologic Record

A standard time scale that divides Earth's history into four eons and further subdivisions.

Anthropocene

Human activity begins.

Stromatolites

Fossilized remains of ancient microbial mats, formed by cyanobacteria.

Mass Extinctions

Times when the rate of extinction has increased dramatically.

Background extinction

Normal extinction rate, refers to the number of species that would be expected to go extinct over a period of time, based on non-anthropogenic (non-human) factors.

Adaptive radiation

Evolution of many diverse species from a common ancestor.

Five Kingdom System

Classifies organisms into Monera, Protista, Fungi, Plantae, and Animalia.

Six Kingdom System

Classifies organisms into Eubacteria, Archaebacteria, Protista, Fungi, Plantae, and Animalia.

Three Domain System

Classifies organisms into Bacteria, Archaea, and Eukarya based on molecular data.

Morphological Species Concept

Defines species based on physical characteristics and appearance.

Mechanical Isolation

Occurs when physical differences prevent successful mating.

Transformation

One species into another, through evolution.

Splitting

Original species into two descendant species.

Continental Movement

Causes long term changes to the climate and location or organisms

Oceanic Anoxia

Reduced mixing of ocean waters caused by volcanic activity or intense global warming

Gondwana and Laurasia

Land masses were caused by Pangaea breaking

Cambrian

Sudden increase in the diversity of many animal phyla

The Big Five Mass Extinctions

Mass extinctions where over 50% of earths species became extinct in one event.

Cladogram

A branching phylogenetic tree

Molecular Homologies

DNA & RNA sequences and each change in a nucleic acid is one evolutionary event.