https://aeon.co/essays/on-epigenetics-we-need-both-darwin-s-and-lamarck-s-theories
Epigenetic transgenerational inheritance, by contrast, occurs when the germline (sperm or egg) transmits epigenetic information between generations, even in the absence of continued direct environmental exposures. Environmental stress and exposure is especially impactful during germline development – for instance, when foetal sex organs develop into testis for men or ovaries for women to produce sperm or eggs later in life. Indeed, environmental exposure during this critical time can trigger permanent epigenetic changes via DNA methylation, histone modifications and alteration of non-coding RNA.
One example that we studied in our lab involved the impact of environmental chemical exposure on trait variation and disease. In our study, we set out to investigate the ability of an environmental toxicant – vinclozolin, the most commonly used fungicide in agriculture today – to alter traits through epigenetic change. First, we briefly exposed a gestating female rat to the fungicide; then we bred her progeny for three generations, to great-grand-offspring, in the absence of any continued exposures. For nearly all males down through the lineage, we observed a decrease in the number and viability of sperm and an associated incidence of infertility with age. And we observed a variety of other disease conditions in both males and females three generations removed from the direct exposure, including abnormalities in the testis, ovaries, kidneys, prostate, mammary glands and brain. Corresponding epigenetic alterations in the sperm involve changes in DNA methylation and non-coding RNA expression.
Our research showed that ancestral exposure to the toxicant vinclozolin also affected sexual selection in animals three generations down the lineage. Considered a major force in evolution since Darwin first posed his theory, sexual selection – also known as mate preference – was assessed by allowing females from other litters to choose between either descendants of exposed or unexposed males. Females overwhelmingly selected those who lacked the transgenerational epigenetic alterations and whose ancestors had not been exposed. In conclusion, exposure to the fungicide permanently altered the descendant’s sperm epigenetics; that, in turn, led to inheritance of sexual selection characteristics known to reduce the frequency with which their genes might propagate in the broader population and directly influence evolution on a micro-evolutionary scale.
so guys, if you can't get a date
blame your grandma