Cited by 1,503Genomics and Phylogenetic StudiesEvolution and Paleontology StudiesEvolution and Genetic Dynamics

Distinguishing Homologous from Analogous Proteins

Fitch, Walter M.·1970·Systematic Zoology

Abstract

Fitch, W. M. (Dept. Physiological Chetn., U. Wisconsin, Madison 53706) 1970. Distinguishing homologous from analogous proteins. Syst. Zool., 19:99–113.—This work provides a means by which it is possible to determine whether two groups of related proteins have a common ancestor or are of independent origin. A set of 16 random amino acid sequences were shown to be unrelated by this method. A set of 16 real but presumably unrelated proteins gave a similar result. A set of 24 model proteins which was composed of two independently evolving groups, converging toward the same chemical goal, was correctly shown to be convergently related, with the probability that the result was due to chance being <10−21. A set of 24 cytochromes composed of 5 fungi and 19 metazoans was shown to be divergently related, with the probability that the result was due to chance being < 10−9. A process was described which leads to the absolute minimum of nucleotide replacements required to account for the divergent descent of a set of genes given a particular topology for the tree depicting their ancestral relations. It was also shown that the convergent processes could realistically lead to amino acid sequences which would produce positive tests for relatedness, not only by a chemical criterion, but by a genetic (nucleotide sequence) criterion as well. Finally, a realistic case is indicated where truly homologous traits, behaving in a perfectly expectable way, may nevertheless lead to a ludicrous phylogen…

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Crossref · 10.2307/2412448

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  • Score-based estimates of phylogenetic relationships between genes are confounded by multiple factors, for example variable sequence evolution rates between genes frequently lead to both false-positive and false-negative errors.

    “However, such score-based estimates of the phylogenetic relationship between genes are confounded by multiple factors. For example, variable sequence evolution rates between genes frequently lead to both false-positive and false-negative errors [14, 15] (Fig. 1).”

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Authors
Fitch, W. M.
Affiliations
University of Wisconsin–Madison (US)
Corresponding author
Fitch, Walter M.
Venue
Systematic Zoology
Published
1970-06
Volume
19
Issue
2
Pages
99
ISSN
0039-7989 (ISSN-L)
OpenAlex
W2159266221
Cited by
1,503
References
0
Citations by year
2026: 20 · 2025: 33 · 2024: 40 · 2023: 28 · 2022: 34 · 2021: 46 · 2020: 59 · 2019: 46 · 2018: 40 · 2017: 50 · 2016: 54 · 2015: 30 · 2014: 79 · 2013: 55 · 2012: 56
FWCI
2.41
Type
journal article
Language
en
Open access
closed
Locations
  • Systematic Zoology (publishedVersion)
  • PubMed (publishedVersion)
Funders
  • National Science Foundation
  • National Institutes of Health
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Genomics and Phylogenetic Studies
  • Physical Sciences › Earth and Planetary Sciences › Paleontology › Evolution and Paleontology Studies
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Genetics › Evolution and Genetic Dynamics
Keywords
protein evolution, convergent evolution, divergent evolution, cytochromes, amino acid sequence, phylogenetic tree, common ancestry
MeSH terms
Biological Evolution, Models, Theoretical, Molecular Biology, Proteins

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