Phylogenetic analysis of homologous genes helps reconstruct evolutionary relationships among genes and gene families. Learn about sequence selection, multiple sequence alignment, phylogenetic methods, evolutionary models, branch support, gene trees, and major applications in comparative genomics.
Gene families are groups of related genes that share a common evolutionary origin. Learn how gene duplication, gene loss, orthology, paralogy, and functional diversification shape gene families and genome evolution.
Learn how gene families are identified using sequence similarity, protein domains, motifs, clustering, orthology, multiple sequence alignment, phylogenetics, and genomic context.
Orthogroups are groups of genes descended from a common ancestral gene across a selected set of species. Learn how orthogroups relate to gene families, orthologs, paralogs, sequence similarity, phylogenetics, and comparative genomics.
Gene family expansion and contraction can be investigated using computational approaches such as gene-family clustering, orthology inference, phylogenetic analysis, gene-tree/species-tree reconciliation, synteny analysis, and evolutionary modeling.
Gene trees and species trees describe different aspects of evolutionary history. Learn how they are constructed, why they can differ, and how duplication, gene loss, incomplete lineage sorting, horizontal gene transfer, and other processes influence evolutionary relationships.
Synteny analysis compares the organization of genes across genomes. Learn how conserved gene order, genomic neighborhoods, and syntenic blocks help study orthologs, gene duplication, gene loss, and genome evolution.
Orthology inference identifies evolutionary relationships between genes using sequence similarity, gene families, phylogenetics, synteny, and computational methods. Learn the major approaches and their limitations.
Reciprocal Best BLAST Hits (RBH) provide a simple approach for identifying candidate orthologs between organisms. Learn how reciprocal BLAST works, how to interpret results, and why RBH does not always prove orthology.
Learn how to identify orthologs using sequence similarity, BLAST, reciprocal best BLAST hits, phylogenetic analysis, synteny, and other bioinformatics approaches used in comparative genomics.
Paralogs are homologous genes that arise through gene duplication. Learn how duplicated genes evolve, how paralogs differ from orthologs, and why they are important in comparative genomics and gene-family evolution.
Orthologs are homologous genes that diverged following speciation. Learn what orthologs are, how they differ from paralogs, and why they are important in comparative genomics, evolution, and genome annotation.
Homologs, orthologs, and paralogs describe different evolutionary relationships between genes. Learn how common ancestry, speciation, and gene duplication distinguish these important concepts in comparative genomics.
Learn how homologs, orthologs, and paralogs describe evolutionary gene relationships and why these concepts are essential for comparative genomics, gene annotation, and evolutionary analysis.
Genomic instability describes the increased tendency of cells to accumulate genetic alterations due to failures in DNA repair, replication fidelity, and chromosome segregation. It plays a central role in cancer development, ageing, and hereditary disorders.
