Species, Evolution, and Genetics Vocabulary

Vocabulary flashcards based on lecture notes covering evolution, taxonomy, phylogenetic trees, and genetics principles.

Evolution

Change in the characteristics of a population over time.

Population

A group of individuals of the same species living in the same area at the same time.

Phylogenetic tree

A diagram showing the evolutionary relationships among organisms.

Node

A branching point on a phylogenetic tree that represents a common ancestor.

Branch

The part of a phylogenetic tree that represents an evolutionary lineage.

Tip

The part of a phylogenetic tree that usually represents a species or group being compared.

Tree of Life

A representation of the evolutionary relationships among Earth's organisms, showing that all organisms are connected through evolutionary history.

Taxonomy

The classification and naming of organisms.

Carolus Linnaeus

Scientist who in 1735 established the classification system in which organisms are classified into hierarchical groups.

Binomial nomenclature

System of naming organisms using two parts: Genus + specific epithet.

Genus

A group of closely related species.

Species

Individuals that regularly breed together or whose characteristics are distinct from those of other species.

Biological species concept

A species concept where reproductive isolation is the major criterion used to determine species boundaries.

Gregor Mendel

Scientist who studied inheritance using garden peas in the 1860s and worked out predictable patterns of inheritance.

Gene

A segment of DNA that encodes a particular polypeptide or cellular product.

Allele

A particular version of a gene.

Diploid

Having 2 sets of chromosomes.

Haploid

Having 1 set of chromosomes.

Gamete

A haploid reproductive cell, such as a sperm or egg cell.

Homozygous

Description of an individual when its two alleles for a gene are the same.

Heterozygous

Description of an individual when its two alleles for a gene are different.

Genotype

The combination of alleles an individual possesses.

Phenotype

The observable characteristics or traits of an organism.

Dominant allele

An allele that is expressed in the phenotype when present in a heterozygote.

Recessive allele

An allele that is not expressed in the phenotype when paired with a dominant allele.

Chromosome Theory of Inheritance

Theory stating that genes are located on chromosomes, connecting Mendelian inheritance to chromosomes.

Modern Synthesis

The mid-20th century integration of Mendelian genetics with Darwinian evolution.