1、Onespecialist species, for example, has valves weighted at the base, acharacteristic that assures that the organism is properly positioned forfeeding in mud and similar substrates.
主要成分：One specialist species has valves ——有一种特殊的物种具有在基底承重的瓣膜（结构）
【主语】One specialist species 【谓语动词】has 【宾语】valves 【valves的后置定语】weighted at the base
其他附加成分：
【插入语】for example, 【base的同位语】a characteristic that assures that the organism is properly positioned for feeding in mud and similar substrates. （这种基底是）一种确保生物体为在泥淖和类似的土质中摄取营养而完全定位特征. 其中—— — 定语从句：that assures that … — 嵌套宾语从句：theorganism is properly positioned for feeding in mud and similar substrates
2、Generalist species now living in arctic water give few if any indications of a tendency towards significant future specialization
主语：Generalist species now living inarctic water 生活在北极水域的广食性物种谓语动词：give 显示出宾语：few indications of a tendencytowards significant future specialization 几乎没有（显示出来）重要的未来适应性变化倾向的迹象插入语：if any 若有任何迹象的话（插入在宾语形容词修饰词few 和名词 indications 之间）
参考译文：生活在北极水域的广食性物种几乎没有,即便有,也很少显示出有价值的未来适应性变化倾向的迹象.