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08:57
Using Phylogenetic Analysis to Investigate Eukaryotic Gene Origin
Published on: August 14, 2018
The common ancestry of life
1National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA. koonin@ncbi.nlm.nih.gov
Biology Direct
|November 20, 2010
Summary
A recent study
Area of Science:
- Evolutionary Biology
- Genomics
- Bioinformatics
Background:
- The Universal Common Ancestry hypothesis posits a single origin for all cellular life.
- Evidence includes the universal genetic code and conserved genes in translation systems.
- A recent study proposed a homology-independent test for this hypothesis.
Purpose of the Study:
- To evaluate a computational method claiming to formally test the Universal Common Ancestry hypothesis.
- To determine if the method provides independent evidence for common ancestry beyond sequence similarity.
Main Methods:
- A computational experiment using concatenated alignments of universally conserved proteins.
- Comparison of a common-ancestry model against a multiple-ancestry model for sequence prediction.
- Analysis of sequence similarity and its role in model-based likelihood estimations.
Main Results:
- The study's findings indicate that the purported demonstration of universal common ancestry is a trivial outcome of inherent protein sequence similarity.
- The origin and nature of sequence similarity were found to be irrelevant to the model-comparison approach's prediction.
- Homology is inferred from sequence similarity, not independently demonstrated by the likelihood analysis.
Conclusions:
- A formal, homology-independent demonstration of the Universal Common Ancestry hypothesis has not been achieved.
- The feasibility of such a demonstration in principle is questioned.
- Despite this, overwhelming evidence from comparative genomics still supports the hypothesis.
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