'Kinds'. including hyperevolution within 'kinds'
Creationists invent their own mutation rate!
Steve Sterley writing on Adam Benton's Filthy Monkey Men blog about Nathaniel Jeanson's mutation rate calculations.
Reviewing “Replacing Darwin” – Part 6: Jeanson’s Fulcrum Fails
Detailed analysis and refutation of Jeanson's mutation rate and his claims about the mitochondrial DNA tree. By EvoGrad. For more on the book by Nathaniel Jeanson that this is dealing with, see Book Replacing Darwin.
Dr. Nathaniel Jeanson Refuted By His Own Data
Critique by biology professor Dan Stern Cardinale and David Neff on Cardinale's Creation Myths YouTube channel. For more on the book by Nathaniel Jeanson that this is dealing with, see Book Replacing Darwin.
Wikipedia page on the 'molecular clock' and different ways in which it is calibrated.
'Epilogue to the Velvet Worm's Tale' in The Ancestor's Tale: A Pilgrimage to the Dawn of Life
Richard Dawkins discusses the molecular clock in simple terms in the chapter 'Epilogue to the Velvet Worm's Tale' in this book.