根据一份报告,使用人造化学肥料和清洁剂造成的水生生态系统化学营养物质的增加(或者称为富营养化)可能对动物造成进化方面的后果。通常,这种营养的过于富集导致藻华以及水中含氧量的下降,这会降低水质和减少动物种群。
Klaus Schwenk及其同事检查了来自瑞士阿尔卑斯山附近两个湖的沉积物样本中关于两种水蚤(一种水生的微小的甲壳纲动物)的一个世纪的数据。由于磷肥使用的增加,这两个湖在20世纪70年代和80年代遇到了富营养化,但是之后恢复到了原来的情况。随着这些湖中磷的浓度增加,水蚤物种之间的平衡发生了变化,两种水蚤形成了几种不同的杂种。杂种成员在磷浓度快速变化的时候达到了顶峰。这组科学家提出,这些杂种表现出了比它们的父母在迅速的环境变化中具有更高的进化适应度。
这组作者说,即便在环境修复之后,这些水蚤保持了它们的杂种状态,表明环境变化可以对一个物种的遗传造成永久的影响。(生物谷Bioon.com)
生物谷推荐原始出处:
PNAS March 9, 2009, doi: 10.1073/pnas.0807187106
The impact of human-made ecological changes on the genetic architecture of Daphnia species
Nora Bredea,b,1, Christoph Sandrocka,2, Dietmar Strailec, Piet Spaakb,d, Thomas Jankowskic,3, Bruno Streita and Klaus Schwenka,14
aDepartment of Ecology and Evolution, Goethe-University Frankfurt am Main, Siesmayerstrasse 70, D-60054 Frankfurt am Main, Germany;
cLimnological Institute, University of Konstanz, D-75457 Konstanz, Germany;
bEawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600 Dübendorf, Switzerland; and
dInstitute of Integrative Biology, ETH Zürich, CH-8092 Zürich, Switzerland
1N.B. and K.S. contributed equally to this work.
Edited by Nelson G. Hairston, Cornell University, Ithaca, NY, and accepted by the Editorial Board February 2, 2009
Abstract
The overenrichment (eutrophication) of aquatic ecosystems with nutrients leading to algal blooms and anoxic conditions has been a persistent and widespread environmental problem. Although there are many studies on the ecological impact of elevated phosphorus (P) levels (e.g., decrease in biodiversity and water quality), little is known about the evolutionary consequences for animal species. We reconstructed the genetic architecture of a Daphnia species complex in 2 European lakes using diapausing eggs that were isolated from sediment layers covering the past 100 years. Changes in total P were clearly associated with a shift in species composition and the population structure of evolutionary lineages. Although environmental conditions were largely re-established after peak eutrophication during the 1970s and 1980s, original species composition and the genetic architecture of species were not restored but evolved along new evolutionary trajectories. Our data demonstrate that anthropogenically induced temporal alterations of habitats are associated with long-lasting changes in communities and species via interspecific hybridization and introgression.