Related Experiment Video
Updated: Jun 30, 2026
05:26
A Venturi Effect Can Help Cure Our Trees
Published on: October 1, 2013
Dating the tree of life
Michael J Benton1, Francisco J Ayala
1Department of Earth Sciences, University of Bristol, Bristol BS8 1RJ, UK. Mike.Benton@bris.ac.uk
Science (New York, N.Y.)
|June 14, 2003
Summary
Molecular and fossil dating methods for evolutionary history show discrepancies, with molecular estimates often being older. However, recent studies indicate these dates are converging as new fossil evidence emerges and molecular data is refined.
Area of Science:
- Evolutionary Biology
- Paleontology
- Molecular Biology
Background:
- Discrepancies exist between molecular and paleontological dating of evolutionary divergences.
- Molecular clock estimates can be significantly older than fossil-based dates.
- Both dating methods have inherent biases: missing fossils for paleontology and statistical biases for molecular data.
Purpose of the Study:
- To investigate the relative accuracy of molecular versus paleontological dating for major evolutionary branching points.
- To understand the reasons behind the observed age discrepancies in evolutionary timelines.
- To assess the convergence of dating estimates through new evidence and refined methodologies.
Main Methods:
- Comparative analysis of molecular clock data and fossil records.
- Evaluation of statistical biases in molecular dating techniques.
- Incorporation of new fossil discoveries to recalibrate paleontological dates.
Main Results:
- Molecular date estimates are frequently twice as old as paleontological dates.
- Paleontological dates are often underestimated due to the fossil record's incompleteness.
- Molecular dates can be overestimated due to systematic biases.
- Recent research on mammalian evolution shows a narrowing gap between molecular and fossil dates.
Conclusions:
- The reconciliation of molecular and paleontological dates is an ongoing process.
- Both methods provide valuable, albeit imperfect, insights into evolutionary history.
- Continued integration of molecular and fossil data is crucial for accurate evolutionary timelines.
Related Concept Videos
03:21Phylogenetic Trees
Phylogenetic trees come in many forms. It matters in which sequence the organisms are arranged from the bottom to the top of the tree, but the branches can rotate at their nodes without altering the information. The lines connecting individual nodes can be straight, angled, or even curved.The length of the branches can depict time or the relative amount of change among organisms. For instance, the branch length might indicate the number of amino acid changes in the sequence that underlies the...
02:39The Angiosperm Life Cycle
Plants have a life cycle split between two multicellular stages: a haploid stage—with cells containing one set of chromosomes—and a diploid stage—with cells containing two sets of chromosomes. The haploid stage is the gamete-producing gametophyte, and the diploid stage is the spore-producing sporophyte.
03:21Phylogenetic Trees
Phylogenetic trees come in many forms. It matters in which sequence the organisms are arranged from the bottom to the top of the tree, but the branches can rotate at their nodes without altering the information. The lines connecting individual nodes can be straight, angled, or even curved.The length of the branches can depict time or the relative amount of change among organisms. For instance, the branch length might indicate the number of amino acid changes in the sequence that underlies the...
01:22Life Tables
A life table is a statistical tool that summarizes the mortality and survival patterns of a population, providing detailed insights into the likelihood of survival or death across different age intervals within a cohort. By organizing data on survival probabilities and mortality rates, life tables offer a clear snapshot of population dynamics over time. They are extensively used in demography, public health, actuarial science, and ecology to analyze life expectancy, design health interventions,...
01:22Applications of Life Tables
Life tables are versatile across various fields, providing a quantitative basis for analyzing mortality and survival rates. Whether used by demographers, actuaries, epidemiologists, or sociologists, life tables offer valuable insights into the dynamics of life and death, facilitating informed decisions in public health, insurance, conservation, and beyond. Their broad applicability highlights the interconnectedness of demographic data with practical outcomes in everyday life and strategic...
01:19Survival Tree
Survival trees are a non-parametric method used in survival analysis to model the relationship between a set of covariates and the time until an event of interest occurs, often referred to as the "time-to-event" or "survival time." This method is particularly useful when dealing with censored data, where the event has not occurred for some individuals by the end of the study period, or when the exact time of the event is unknown.
Building a Survival Tree
Constructing a survival tree begins...
Building a Survival Tree
Constructing a survival tree begins...