Malthus argued that natural populations grow at an exponential rate, whereas the increase in food supply is linear.
Malthus论证说，自然群体的数量是呈指数级增长的，而食物供应的增加却是呈线性的。
One of the most universal phenomena of all natural populations is their variability in Numbers in space and time.
自然种群最普遍的现象是其数量在时间和空间上的变异性。
But as all zoologists know, experiments can only tell you so much. Eventually, you have to look at natural populations.
然而动物学家都清楚，实验提供的依据再多，最终也还是要看自然种群。
If we take from the wild we must do it in ways that allow natural populations to recover and last long into the future.
如果我们在野外，我们必须采取的这样的方式使自然种群的恢复和持续，一直持续到未来很长的时间里。
But it's hard to tell in most natural populations whether inheritance is due to DNA sequence variation or epigenetic changes.
但在自然界大多数种群中，很难判断遗传是否源于DNA序列改变或者表观基因变异。
But a question clouding the field's future has been how to "replace" natural populations with these new and improved mosquitoes.
本领域未来如何用新改良蚊子“替换”自然群体的问题还很模糊。
UPGMA cluster analysis showed that natural populations and cultivated populations were distinctly separated into two groups.
UPGMA聚类分析表明自然居群与栽培居群存在明显的分化而分别聚为两大类群。
Association mapping is one of the important ways to detect QTLs and reveal genetic bases of target traits in the natural populations.
利用自然群体进行关联分析是检测目标性状qtl、揭示其遗传基础的有效方法。
Results the predominant antibody of serogroup was Sejroe with positive rates of 34.13% and 25.82% in patients and natural populations respectively in these areas.
结果该地区自然人群及病人血清抗钩端螺旋体抗体现以赛罗群棉兰型为主，其阳性率分别为34.13%和25.82%。
Secondly, I compared the genetic structure of artificial populations of M. glyptostroboides with the natural populations' and discuss the genetic consequence of the recovery.
然后通过种群遗传分析，比较现有水杉人工种群与自然种群的遗传结构异同，探讨人工种群遗传结构是否得到恢复；
In natural populations, individuals often are distributed more or less discontinuously to form numerous colonies, and individuals may be exchanged between adjacent or nearby colonies.
在自然种群中，个体往往分布不连续，从而形成或多或少的聚居点，相邻或邻近的聚居点之间有一定的个体交流。
It's in these populations that we begin to see real changes in the genetic makeup of natural coloring.
正是在这些种群中，我们开始看到自然色彩的基因构成发生了真正的变化。
The Natural Resources Defense Council says federal standards that states rely on are outdated and don't do enough to protect vulnerable populations that eat a lot of seafood.
美国国家自然资源保护委员会说，有关各州依据的联邦标准是过时的并且不能充分保护那些大量食用海产品的敏感人群。
FAO is promoting an integrated approach to coastal area management that balances the needs of local populations with environmental and natural resource management considerations.
粮农组织正在推行对沿海地区的综合管理举措，将协调当地人口需求与环境和自然资源管理方面的考虑。
In some regions, natural disasters or misguided policies, or both, compound already severe situations and render them catastrophic for the most discriminated and marginalized populations.
在某些地区中，自然灾害或不当的政策或是两者皆有之的情形不仅加剧了本已严峻的形势，还使那些最受歧视或处于社会边缘的人群遭受更大的灾难。
With time, natural selection will tend to flush the deleterious SNPs out, as it has done — relatively speaking — in African populations.
假以时日，自然选择会逐渐清除有害的SNPs，就像它曾经对非洲群体——相对而言——所作的那样。
The locations and dense construction patterns of cities often place their populations at greater risk for natural disasters, including those expected to worsen with climate change.
城市的地理位置及其密集的建设模式经常置它们的居民于更大的自然灾害(包括那些因为气候变化可能加剧的)危险之中。
Emergencies - whether caused by conflict or natural disasters - are extraordinary events that can jeopardize the health and survival of large populations.
紧急情况——或由冲突或由自然灾害导致——是可能危害大量人健康与生存的不寻常事件。
With few natural predators, they have been rapidly expanding in Caribbean and Atlantic waters, voraciously preying on local fish, shrimp and crab populations across the region.
狮子鱼的天敌极少，主要以小鱼、虾和螃蟹味主食，它们在加勒比海和大西洋海域迅速繁殖起来。
Brancato says skunk populations can grow large because they don't really have any natural predators.
布兰·卡多表示，由于臭鼬在自然界没有任何天敌，它们的数量就会增加到很多。
And so this particular insect, because it is an invasive, it has no native natural enemies per se. It has no natural enemies that are really very effective at controlling populations of this insect.
因为这种特别的昆虫是入侵生物，所以它们本身在当地没有天敌，没有能有效控制它们数量的天敌。
Populations increase and decrease relatively not only to one another, but also to natural resources.
人口的增减不仅彼此相关，也和自然资源息息相关。
Hybridization is a prominent feature of natural plant populations, and one that often leads to speciation, either through polyploidization or at the diploid level.
远缘杂交是许多天然植物种群的一个显著特性，其结果往往是通过多倍体化或者在二倍体水平上形成新物种。
Hybridization is a prominent feature of natural plant populations, and one that often leads to speciation, either through polyploidization or at the diploid level.
远缘杂交是许多天然植物种群的一个显著特性，其结果往往是通过多倍体化或者在二倍体水平上形成新物种。
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