(单词翻译:单击)
听力文本
This is Scientific American — 60-Second Science. I'm Karen Hopkin.
Living with your parents has its benefits...at least when it comes to raising your kids—their grandkids. Because two new studies add to the evidence that grandmothers can enhance the survival of grandchildren. That is, unless grandma's too old or lives too far away. The results appear in the journal Current Biology.
Humans are unusual in that the females live long past the age at which they stop having babies.
"We don't really see that in nature. Most of the organisms will reproduce up to their very last moment."
Patrick Bergeron, professor of biology at Bishop's University in Quebec.
This increase in post-reproductive longevity is often explained by the so-called “grandmother effect.
"Because family members share their genes, there could still be a benefit for postmenopausal women to increase their genetic footprint by helping their daughters to rear larger families."
To explore the “grandmother effect” hypothesis, Bergeron and his colleagues examined nearly 200 years' worth of French-Canadian population records from the 17th and 18th centuries.
"At the time, life was tough. In some years, a third of the kids were not even making it to one year of age."
But the researchers found that having a grandmother still alive was a definite plus.
"Families with grandmothers alive were larger by about two and the survival of these grandchildren to age 15 was much improved."
This beneficial effect was only seen when the matriarchs lived nearby. Which suggests that grandmothers help by playing an active role in their grandchildren's lives. Unfortunately, that role is tougher for them to fulfill as they get older. Which brings us to the second study.
Researchers at the University of Turku in Finland used church records from the 18th and 19th centuries. They found that the benefits associated with having a grandmother on hand depended on her age. Once nanna hit 75, the grandchild survival benefit disappeared—and then some.
"In other words, it was better for grandchildren to have no living grandmother at all than it was to live with an old one or one that was in poor health."
Simon Chapman, a doctoral student in biology.
"This was almost certainly due to some form of indirect resource competition, though, rather than wickedness on the part of co-resident grandmothers."
So a healthy grandma helps make for a healthy grandchild. If "over the river and through the woods to grandmother's house" isn't too long a trip.
Thanks for listening for Scientific American — 60-Second Science. I'm Karen Hopkin.
参考译文
这里是科学美国人——60秒科学。我是凯伦·霍普金。
和父母一起住是有好处的，至少在抚养你的孩子也就是他们的孙辈时是如此。因为两项新研究再次提供了祖母能提高孙辈生存率的新证据。除非祖母年纪太大或住得太远。研究结果发表在《当代生物学》期刊上。
人类的不同寻常之处在于，雌性的寿命远远超过停止生育的年龄。
“我们在自然界中没有看到过这种现象。大多数生物会一直繁殖，直到生命的最后一刻。”
魁北克毕索大学的生物学教授帕特里克·伯格伦说到。
这种繁殖后期寿命延续现象通常可以用所谓的“祖母效应”来解释。
“由于家庭成员有共同的基因，这可能仍有助于绝经后的女性通过帮助女儿抚养更大的家庭，来增加自己的基因足迹。”
为了探索“祖母效应”假说，伯格伦和同事研究了17世纪至18世纪的近200年的法裔加拿大人口记录。
“当时，生活非常艰苦。在有些年份，三分之一的孩子甚至都活不到一岁。”
但研究人员发现，祖母健在绝对是个有利因素。
“祖母健在的家庭，成员人数大约会多2人，孙辈活到15岁的几率也大大提高了。”
只有在年长女性生活在附近时，这种有益作用才会显现出来。这表明，祖母通过在孙辈的生活中扮演积极角色来帮助他们。不幸的是，随着年龄增长，她们所扮演角色的作用越来越难以实现。这就引出了第二个研究。
芬兰图尔库大学的研究人员使用了18和19世纪的教会记录。他们发现，有祖母在身边的益处取决于她们的年龄。一旦祖母到了75岁，孙辈的生存益处就会消失——而且还远不止如此。
“换句话说，对孙辈来说，相比与年迈或身体不好的祖母生活在一起，身边没有祖母的生活更好。”
生物学博士生西蒙·查普曼说到。
“不过，这几乎可以肯定是由于某种间接的资源竞争，而不是共同居住的祖母做了坏事。”
因此，健康的祖母有助于造就健康的孙辈。前提是，“过河穿过树林到祖母家”的路程不太远。
谢谢大家收听科学美国人——60秒科学。我是凯伦·霍普金。
译文为可可英语翻译，未经授权请勿转载！
重点讲解
重点讲解：
1. on hand 在手头；在近处；现有；
The Bridal Department will have experts on hand to give you all the help and advice you need.
婚礼用品部会有现成的专家为您提供所需的一切帮助和建议。
2. and then some 远不止这些；此外还有不少；
We got our money's worth and then some.
我们不仅得了按价钱应得的，而且还捞到了不少。
3. on the part of 由某人所为；
They suspected this was a double bluff on the part of Cairo Intelligence.
他们怀疑这是开罗情报人员玩的空城计。
4. make for 导致；有利于；
A happy parent makes for a happy child.
有快乐的父母，才会有快乐的孩子。
