Revising the Age of Placental Mammals
Author Information
Author(s): Kitazoe Yasuhiro, Kishino Hirohisa, Waddell Peter J., Nakajima Noriaki, Okabayashi Takahisa, Watabe Teruaki, Okuhara Yoshiyasu
Primary Institution: Center of Medical Information Science, Kochi Medical School, Nankoku, Kochi, Japan
Hypothesis
The study aims to reconcile molecular and paleontological estimates of divergence times for placental mammals.
Conclusion
The new methods provide a more recent estimate for the root of placental mammals, aligning molecular data with fossil records.
Supporting Evidence
- The new methods showed good performance in simulations compared to current methods.
- The estimated age of the root of placental mammals was revised from around 122 million years ago to close to 84 million years ago.
- The results align better with the North American fossil record.
- By correcting for convergent evolution, the study provides a more accurate timeline for placental mammal divergence.
Takeaway
Scientists found that placental mammals are younger than previously thought, using new methods to analyze their evolutionary history.
Methodology
The study used a multidimensional vector space procedure to estimate divergence times while accounting for convergent evolution.
Potential Biases
Potential biases from uncorrected convergent evolution and model misspecification could affect the results.
Limitations
The study's estimates may still be influenced by the assumptions made in the modeling of evolutionary rates.
Participant Demographics
The study analyzed mitochondrial protein sequences from 69 placental mammals and 7 outgroup taxa.
Statistical Information
P-Value
p<0.05
Confidence Interval
80.7–88.4 mya
Statistical Significance
p<0.05
Digital Object Identifier (DOI)
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