Understanding Diversity and Systematics in Biology

Vertical Gene Transfer

Gene transmission from parent to offspring.

Phylogeny

Evolutionary history of a group of organisms.

Microscopy

Use of microscopes to study small organisms.

Monophyletic Group

Includes an ancestor and all its descendants.

Paraphyletic Group

Contains a common ancestor and some descendants.

Tetrapoda

Newly recognized taxon including all four-limbed vertebrates.

Cladistic Methodology

Focuses on shared derived characters for classification.

Biodiversity

Variety of living organisms and ecosystems.

Systematics

Study of organism diversity and evolutionary relationships.

Taxonomy

Science of naming and classifying organisms.

Classification

Grouping organisms based on evolutionary similarities.

Homologous Traits

Shared traits from common ancestors.

Binomial Nomenclature

Two-part naming system for species.

Genus

First part of a species' binomial name.

Specific Epithet

Second part of a species' binomial name.

Taxonomic Hierarchy

Species organized into broader groups.

Taxon

Formal grouping of organisms at any level.

Five-Kingdom Classification

System categorizing life into five kingdoms.

Prokaryotic

Organisms without a true nucleus.

Eukaryotic

Organisms with a true nucleus.

Phylogenetic Tree

Diagram showing evolutionary relationships.

Cladogram

Type of phylogenetic tree showing clades.

Horizontal Gene Transfer

Gene transfer between different species.

Endosymbiosis

Symbiotic relationship leading to organelle evolution.

Homology

Shared ancestry between structures or genes.

Convergent Evolution

Unrelated species develop similar traits.

Homoplasy

Similar traits due to environmental adaptation.

Reversal

Trait reverts to ancestral state.

Ernst Haeckel

Proposed kingdom Protista in 1866.

Carl Woese

Identified Bacteria and Archaea in 1970s.

R. H. Whittaker

Proposed five-kingdom system in 1969.

Gene Sequence

Order of nucleotides in DNA/RNA.

Common Ancestor

An ancestor shared by different species.

Homologous Structures

Traits derived from a common ancestor.

Shared Ancestral Characters

Traits present in an ancestor and descendants.

Vertebral Column

Example of a shared ancestral character in vertebrates.

Shared Derived Characters

Novel traits indicating divergence between groups.

Clade

Group of organisms sharing derived characters.

Synapomorphies

Shared derived characters among a clade.

Plesiomorphies

Ancestral characters shared with distant relatives.

Molecular Systematics

Uses molecular data to clarify evolutionary relationships.

Molecular Clocks

Estimate time since divergence using molecular changes.

Ribosomal RNAs (rRNA)

Used to analyze evolutionary relationships among organisms.

Polyphyletic Group

Includes unrelated lineages without a common ancestor.

Outgroup Analysis

Identifies shared derived characters using an outgroup.

Branch Points

Indicate divergence events in a cladogram.

Principle of Parsimony

Simplest explanation preferred in cladogram construction.

Maximum Likelihood

Statistical method for analyzing molecular data.

Cytochrome Oxidase

Molecular marker considered for DNA barcoding.

Evolutionary Taxonomy

Integrates evolutionary relationships with traditional classification.

Phenetics

Numerical taxonomy based on overall similarity.

Molecular Barcoding

Identifies species using short, unique DNA sequences.

Nucleotide Sequences

Used to construct phylogenetic trees for viruses.

Cladogram Construction

Organizes character states to reflect evolutionary order.

Statistical Methods

Used when ancestral and derived states are unclear.

Evolutionary Relationships

Connections among organisms based on shared ancestry.