Related Experiment Video
Updated: Aug 15, 2026

Using Phylogenetic Analysis to Investigate Eukaryotic Gene Origin
Published on: August 14, 2018
The phylogenetic and evolutionary history of a novel alpha-globin-type gene in orangutans (Pongo pygmaeus)
Michael E Steiper1, Nathan D Wolfe, William B Karesh
1Department of Anthropology, Hunter College of the City University of New York, New York, USA. msteiper@hunter.cuny.edu
Abstract:
The alpha-globin genes are implicated in human resistance to malaria, a disease caused by Plasmodium parasites. This study is the first to analyze DNA sequences from a novel alpha-globin-type gene in orangutans, a species affected by Plasmodium. Phylogenetic methods show that the gene is a duplication of an alpha-globin gene and is located 5' of alpha-2 globin. The alpha-globin-type gene is notable for having four amino acid replacements relative to the orangutan's alpha-1 and alpha-2 globin genes, with no synonymous differences. Pairwise K(a)/K(s) methods and likelihood ratio tests (LRTs) revealed that the evolutionary history of the alpha-globin-type gene has been marked by either neutral or positive evolution, but not purifying selection. A comparative analysis of the amino acid replacements of the alpha-globin-type gene with human hemoglobinopathies and hemoglobin structure showed that two of the four replaced sites are members of the same molecular bond, one that is crucial to the proper functioning of the hemoglobin molecule. This suggested an adaptive evolutionary change. Functionally, this locus may result in a thalassemia-like phenotype in orangutans, possibly as an adaptation to combat Plasmodium.
Related Concept Videos
Gene Duplication and Divergence
The duplicated copies of the gene are called Paralogs. Paralogs with similar sequences and functions form a gene family. Across several species, a large number of gene families are characterized.
Exon Recombination
Exon shuffling follows “splice frame rules.” Each exon has three reading...
Synteny and Evolution
Around 80 million years ago, the human and mice lineages diverged from the common ancestor. During the course of evolution, the ancestral chromosome underwent...
Protein Families
Evolutionary Relationships through Genome Comparisons
Gene Evolution - Fast or Slow?
In contrast, regions which code...

