Molecular dating rates vary

These changes accrue like the ticks on a stopwatch, providing a “molecular clock.” By comparing DNA sequences, geneticists can not only reconstruct relationships between different populations or species but also infer evolutionary history over deep timescales.

Molecular clocks are becoming more sophisticated, thanks to improved DNA sequencing, analytical tools and a better understanding of the biological processes behind genetic changes.

molecular dating rates vary-3

Molecular dating is used in the biological sciences to estimate the age of evolutionary events.

Changes to DNA and amino acid sequences accumulate continuously in the genome over time, so comparing DNA sequences between lineages allows us to estimate the time since they last shared a common ancestor.

However, the rate of change varies across the genome and among species.

So in order to use molecular data to date evolutionary events, we need a way of estimating the rate of change in genetic sequences over time for any given dataset.

DNA holds the story of our ancestry – how we’re related to the familiar faces at family reunions as well as more ancient affairs: how we’re related to our closest nonhuman relatives, chimpanzees; how mated with Neanderthals; and how people migrated out of Africa, adapting to new environments and lifestyles along the way.