时间:2018-12-02 作者:英语课 分类:2016年Scientific American(十二)月


英语课

 


Human parents usually have one or sometimes two offspring at a time, and when babies get delivered we pour all our energy into child rearing. But other animals raise lots of babies at once. And the weaker individuals can be at a big disadvantage. If there's not enough food, for example, a mother bird might offer more to those chicks who are more likely to survive. Nature's a rough place.


But mammals like pigs can't selectively provision their offspring the way birds do, because all the babies nurse at the same time. And yet the strongest piglets still seem to have an edge. One hypothesis goes that the weaklings might not have sufficient energy to stimulate 1 the mammary gland 2 while they suckle, so they eventually starve from a lack of nutrition.


But it turns out that vigorous stimulation 3 of one mammary gland can increase blood flow in neighboring glands 4. So if a weakling was canny 5 enough to position himself next to one of his strongest siblings 6, he might get more milk than positioned elsewhere.


"I got this idea during observations of piglets, of course, because I had a feeling that weaklings are doing better in the company of [the] strongest siblings."


Biologist Janko Skok from Slovenia's University of Maribor.


To see if his hunch 7 was right, Skok observed 18 litters, including 150 piglets. Twenty-three of them were classified as weaklings, which meant they weighed less than one kilogram at birth or they died before weaning. Then he looked to see what differentiated 8 the weaklings that survived from those that died.


And indeed, those weaklings that survived were more likely to nurse next to their strongest brothers and sisters. "Weaklings, which are limited in terms of mammary gland stimulation, actually take advantage of strong stimulation implemented 9 by their heavier siblings, who in turn do not suffer any costs from this activity."


The research were published in the journal Behavioural Processes. [Janko Skok, Being a weakling and surviving: Keep the fittest siblings close-by when eating.]


Skok says that pig breeders commonly sort piglets into different weight classes, so the heaviest babies nurse together with one mother while a different mother raises the weaker babies. But his results might mean that more piglets could survive if breeders instead mixed piglets of different sizes, so that the smaller ones could take advantage of their larger counterparts.


What this finding does not explain is why my younger brother, who as a kid always and failed to steal my dessert, is now stronger than I am.


—Jason G. Goldman



1 stimulate
vt.刺激,使兴奋;激励,使…振奋
  • Your encouragement will stimulate me to further efforts.你的鼓励会激发我进一步努力。
  • Success will stimulate the people for fresh efforts.成功能鼓舞人们去作新的努力。
2 gland
n.腺体,(机)密封压盖,填料盖
  • This is a snake's poison gland.这就是蛇的毒腺。
  • Her mother has an underactive adrenal gland.她的母亲肾上腺机能不全。
3 stimulation
n.刺激,激励,鼓舞
  • The playgroup provides plenty of stimulation for the children.幼儿游戏组给孩子很多启发。
  • You don't get any intellectual stimulation in this job.你不能从这份工作中获得任何智力启发。
4 glands
n.腺( gland的名词复数 )
  • a snake's poison glands 蛇的毒腺
  • the sebaceous glands in the skin 皮脂腺
5 canny
adj.谨慎的,节俭的
  • He was far too canny to risk giving himself away.他非常谨慎,不会冒险暴露自己。
  • But I'm trying to be a little canny about it.但是我想对此谨慎一些。
6 siblings
n.兄弟,姐妹( sibling的名词复数 )
  • A triplet sleeps amongst its two siblings. 一个三胞胎睡在其两个同胞之间。 来自《简明英汉词典》
  • She has no way of tracking the donor or her half-siblings down. 她没办法找到那个捐精者或她的兄弟姐妹。 来自时文部分
7 hunch
n.预感,直觉
  • I have a hunch that he didn't really want to go.我有这么一种感觉,他并不真正想去。
  • I had a hunch that Susan and I would work well together.我有预感和苏珊共事会很融洽。
8 differentiated
区分,区别,辨别( differentiate的过去式和过去分词 ); 区别对待; 表明…间的差别,构成…间差别的特征
  • The development of mouse kidney tubules requires two kinds of differentiated cells. 小鼠肾小管的发育需要有两种分化的细胞。
  • In this enlargement, barley, alfalfa, and sugar beets can be differentiated. 在这张放大的照片上,大麦,苜蓿和甜菜都能被区分开。
9 implemented
v.实现( implement的过去式和过去分词 );执行;贯彻;使生效
  • This agreement, if not implemented, is a mere scrap of paper. 这个协定如不执行只不过是一纸空文。 来自《现代汉英综合大词典》
  • The economy is in danger of collapse unless far-reaching reforms are implemented. 如果不实施影响深远的改革,经济就面临崩溃的危险。 来自辞典例句
学英语单词
a job of work
advertising policy
aged meat
and that sort of thing
beins
bobfergusonite
book-hoard
bronchial breathing sound
burnt offerings
caustic magnesite
Central Air Documents Office
Chao Phraya River
characteristic tide level
chiasmatype theory
childhead
classtimes
conservatorship
copperply wire
corsinia marchantioides raddi
Courant, Richard
crose
dashplate
delsing
depth line accuracy
desmethyl-limipramine
differential-mode signal
electric resistance weld mill
engaging pressure
Eri.
EW equipment
exclusive stress on material benefits
existentialist
fertilization substance
file number
filtration barrier
gaits
geauga
genus lobelias
genus Trichomanes
glass silk-wrapped enameled copper wire
Glauconex
grey system
group devisible incomplete block design
gyro flux-gate compass
hang glide
ignace paderewskis
II-VI group solar cell
insulating measuring bench
interstate commerce act
iron family
jacqueline
janiceps asymmetros
jukin'
kerr
kovalenko
la fille du pharaon
laslo
leaching rate
lefft-hand rule
made an exception of
magnetic boundary
melaminylphenylstibonic acid
method of fractional steps
mouse roller
natural hat trick
Nerzweiler
No bottom sounding!
ofiesh
ore conditioning
palmester
Pingliang
playsome
pore diffusion resistance
Priotropis cytisoides
procumbent teeth
propyl radicals
Pyasina
quanset
raster unit
refugo
resultant touch
revenue funds
Schallibaum's solution
Sorbus alnifolia
spede
spreading ridge
structural(tectonic)basin
subjective units of distress scale (suds)
take somebody's life
title-
tridecyls
turret steamer
ucans
ultimate holding company
unbounded set
universal lacquer
uranyl sulfide
vitznau
wallaces
water attack
wilgen
writen