The decelaration of the Earth's rotation speed, when given by the increase of the length of day, is nearly 2 milliseconds per century, i.e. 2 seconds in 100,000 years or 1 hour in 180 million years. I do not think that this very small increase effects biological clocks, at least not over time spans of the order of thousands of years. Perhaps an effect could be seen if we could compare the biological clocks of the oldest living higher species (e.g. ferns) at the beginning of their existence some 100 millions years ago with those of today's ferns, but this is impossible, I think.

This a dimensional analysis question. And such it compares two time scales: the characteristic time of rotation change and the time of animal adaption. The typical time of animal adaption was suggested to be in 10 generations (for some animals). For example, human that going through famine lose IQ and it stay with them about 10 generation. While this change is grossly accurate but it does provide the time scale for a genetic change. Thus according to this logic it take about 250 years to change the DNA or what some call peso DNA). In dogs it said that it take about 4 generations to remove the aggressiveness which make it about 28 years. No matter the accuracy of these estimates, the time scale for human/dog evolution seems to be in the range up to 1000 years. If this analysis is correct then the adaptation is much faster than the change of rotation.