Question

Molecular clocks and how you would assess whether taxa are evolving in a "clock-like" manner

Answer 1

Molecular clocks are a method to estimate relatedness among species based on DNA sequences. To assess whether taxa are evolving in a "clock-like" manner, DNA sequences need to be collected, aligned, and analyzed to determine the number of differences between species.

Step-by-step explanation:

Molecular Clocks and Assessing “Clock-Like” Evolution

Molecular clocks are based on the assumption that mutations accumulate through time at a steady average rate for a given region of DNA. To assess whether taxa are evolving in a "clock-like" manner, several steps can be taken:

1. Collect DNA sequences from multiple taxa and choose a region of DNA that evolves at a regular rate.
2. Align the DNA sequences and count the number of differences between each pair of taxa.
3. Construct a phylogenetic tree based on the DNA sequence differences.
4. Compare the branch lengths of the tree. If the branch lengths are roughly equal, it suggests a clock-like evolution. If the branch lengths vary significantly, it indicates a non-clock-like evolution.