根據(jù)一份報告,,使用人造化學肥料和清潔劑造成的水生生態(tài)系統(tǒng)化學營養(yǎng)物質的增加(或者稱為富營養(yǎng)化)可能對動物造成進化方面的后果。通常,,這種營養(yǎng)的過于富集導致藻華以及水中含氧量的下降,,這會降低水質和減少動物種群,。
Klaus Schwenk及其同事檢查了來自瑞士阿爾卑斯山附近兩個湖的沉積物樣本中關于兩種水蚤(一種水生的微小的甲殼綱動物)的一個世紀的數(shù)據(jù)。由于磷肥使用的增加,,這兩個湖在20世紀70年代和80年代遇到了富營養(yǎng)化,,但是之后恢復到了原來的情況。隨著這些湖中磷的濃度增加,,水蚤物種之間的平衡發(fā)生了變化,,兩種水蚤形成了幾種不同的雜種。雜種成員在磷濃度快速變化的時候達到了頂峰,。這組科學家提出,,這些雜種表現(xiàn)出了比它們的父母在迅速的環(huán)境變化中具有更高的進化適應度,。
這組作者說,即便在環(huán)境修復之后,,這些水蚤保持了它們的雜種狀態(tài),,表明環(huán)境變化可以對一個物種的遺傳造成永久的影響。(生物谷Bioon.com)
生物谷推薦原始出處:
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.