英语听力：自然百科 探索世界奥秘之The Ghost In Your Genes(基因外遗传现象) Unit011（在线收听）

探索世界奥秘之The Ghost In Your Genes(基因外遗传现象) Unit11

But could this effect be transmitted to their offspring?

They found nearly 200 women of whom a number had actually been in the Twin Towers. About half of them developed post-traumatic stress disorder. We then looked at those women and found they had abnormal cortisol in their saliva. The most striking finding was, so did their babies. The argument in the Holocaust survivors had been that their children show abnormal stress hormones because they themselves have been stressed by listening to these tales recounted by their parents of their awful exposures during the 1940s. That could not be the case with the 9/11 survivors. These babies were one year old.

Not only did infants had lower cortisol levels but they were different, depending on how pregnant the mother was on 9/11.

The main effect was only seen with those mothers with PTSD who were pregnant in the last third of pregnancy. Mothers with equal levels of PTSD who were pregnant in the first and second third of pregnancy at 9/11, there was very little effect on the babies' cortisol.

It suggested to us there couldn't just be about genetics, but there was something that was being transmitted in the late stages of pregnancy where the mother's symptoms were having some effect on the development of the offspring's cortisol system.

It appeared that epigenetics might be responsible that an event had altered the stress response in the children .

What these findings did was suggest to us that we need to be looking where we hadn't even considered looking before.

To know for certain, that this was an epigenetic effect, they'll need to be sure that their observations weren't simply due to high levels of stress hormones in the womb.

Now and here is the bit where we have to speculate. The animal work would suggest that this might then persist into the next generation.

If they find the same stress effects in the children's children of 9/11, then it will be clear that a genetic memory of a stressful event can travel through the generations.

That's the key thing next to find out. But the 9/11 population will be very very important for us to be able to follow what is a single discrete event.

The work of Yehuda and Seckl offers tantalizing evidence of proof of inherited epigenetic effects in humans. But they need data that extends beyond just one generation. The only way forward was to look back to the past. In Sweden, Pembrey and Bygren had data that provided the chance to study the effects of famine through many generations.

New Words & Phrases:

tantalize: If someone or something tantalizes you, they make you feel hopeful and excited about getting what you want, usually before disappointing you by not letting you have what they appeared to offer. 强烈的诱惑, 逗惹