If a clock measures time, what does a molecular clock measure?A molecular clock can measure the degree of similarity - or difference - between molecules of different species. What would a few differences between DNA or protein sequences mean? What would many differences represent?
___________________________________________________________________________
Molecular Clocks
"It doesn't tick, it doesn't have hands, and it doesn't tell you what time of day it is. But a molecular clock does tell time -- on an epoch scale." S. Blair Hedges
Fossils only provide a certain amount of information. With the advent of molecular biology, additional information has allowed evolutionary biologists to unearth additional, informative discoveries. Further confirmation of common ancestry includes the analysis of molecular clocks.
These measure changes in DNA or protein sequences to indicate degrees of relationship among species. When analyzing common genes or proteins from different species, fewer differences among the nucleotide or amino acid sequences demonstrates a closer degree of evolutionary relatedness among two species. Both DNA and protein clocks support a universal common ancestor of life, confirming the story which continues to unfold as new discoveries expand the fossil record. Molecular clocks, together with evidence from the fossil record, allow scientists to estimate how long ago various groups of organisms diverged evolutionarily from one another.
___________________________________________________________________________
Molecular Clocks
"It doesn't tick, it doesn't have hands, and it doesn't tell you what time of day it is. But a molecular clock does tell time -- on an epoch scale." S. Blair Hedges
Fossils only provide a certain amount of information. With the advent of molecular biology, additional information has allowed evolutionary biologists to unearth additional, informative discoveries. Further confirmation of common ancestry includes the analysis of molecular clocks.
These measure changes in DNA or protein sequences to indicate degrees of relationship among species. When analyzing common genes or proteins from different species, fewer differences among the nucleotide or amino acid sequences demonstrates a closer degree of evolutionary relatedness among two species. Both DNA and protein clocks support a universal common ancestor of life, confirming the story which continues to unfold as new discoveries expand the fossil record. Molecular clocks, together with evidence from the fossil record, allow scientists to estimate how long ago various groups of organisms diverged evolutionarily from one another.
Click button to complete Molecular Clock Simulation before you complete your lab activity.