Thanks for these comments Amy. Yes, some say epigenetics research puts Lamarck in a new light. I think the duration of intergenerational transmission remains very unclear, partly because it's so hard to study.
The evidence on social mobility with respect to income suggests several generations on average for a child in the US to recover to average income if his parents/grandparents/great grandparents were impoverished. I wonder if epigenetic marks are so enduring.