Genetic progress forward

Is a clone equal to its model ?

An individual isn't only made of nuclear genes. His environment interfers and, although identical, his genes might not be absolutely activated the same way. His mitochodria as well might account for some differences.

What geneticists call heritability is the variability part between individuals which genes are responsible for. It will fluctuate between 15 and 50 % according to characters whereas 50 to 85 % are linked to the environment.
Thus, and at the best, a clone and its model won't be more than two identical genetic duplicates but no more similar than true twins.

In terms of cloning, an imperfect genes performance "reprogramming" might lead to differences : this phenomenon, known as epigenetic phenomenon, explains gestation anomalies and increased pregnancy losses.
When they are a few weeks old, clones are normal. Eventual phenotypic differences are no more than those statistically expected. Thereby, growth rates or dairy production for cloned cows stick to genetics calculation.
Theoretically, mitochondria that originate from the receiving oocyte may be responsible for differences between the clone and its model. However in practice no differences have been explained by the oocyte origin of mitochondria. This is yet a major issue if considering sport performances field, since mitochondria are the cell energetic agent.

Future time will confirm whether mitochondrial differences might be brought to light.