Guest essay by Eric Worrall
Australian scientists have discovered that Damselflies which are better at surviving a warmer climate pass their genetic advantages on to their offspring. But they recommend more studies to determine whether other species are capable of adapting to changed conditions.
Are damselflies in distress?
How are insects responding to rapid climate change?
Damselflies are evolving rapidly as they expand their range in response to a warming climate, according to new research led by Macquarie University researchers in Sydney.
“Genes that influence heat tolerance, physiology, and even vision are giving them evolutionary options to help them cope with climate change. Other insects may not be so lucky,” says Dr Rachael Dudaniec, lead author of the paper.
The study, published in Molecular Ecology today, investigated the genetics of an insect’s capacity to adapt and survive in a changing world by looking at the blue-tailed damselfly (Ischnura elegans) in Sweden.
“Damselflies, like other aquatic insects, are faced with a dilemma given the current and unprecedented rate of global warming,” says Rachael.
“Either they perish, move elsewhere or adapt to the new environmental conditions. It’s a classic case of fight or flight.”
But, she warns, this is certainly not the case for all species.
“Our research highlights the need to further investigate how different species will cope with climate change,” says Rachael.
The abstract of the study;
Signatures of local adaptation along environmental gradients in a range‐expanding damselfly (Ischnura elegans)
Rachael Y. Dudaniec Chuan Ji Yong Lesley T. Lancaster Erik I. Svensson Bengt Hansson
First published: 29 April 2018
Insect distributions are shifting rapidly in response to climate change and are undergoing rapid evolutionary change. We investigate the molecular signatures underlying local adaptation in the range‐expanding damselfly, Ischnura elegans. Using a landscape genomic approach combined with generalized dissimilarity modelling (GDM), we detect selection signatures on loci via allelic frequency change along environmental gradients. We analyse 13,612 Single Nucleotide Polymorphisms (SNPs), derived from Restriction site‐Associated DNA sequencing (RADseq), in 426 individuals from 25 sites spanning the I. elegans distribution in Sweden, including its expanding northern range edge. Environmental association analysis (EAA) and the magnitude of allele frequency change along the range expansion gradient revealed significant signatures of selection in relation to high maximum summer temperature, high mean annual precipitation, and low wind speeds at the range edge. SNP annotations with significant signatures of selection revealed gene functions associated with ongoing range expansion, including heat shock proteins (HSP40 and HSP70), ion transport (V‐ATPase) and visual processes (long wavelength‐sensitive opsin), which have implications for thermal stress response, salinity tolerance and mate discrimination, respectively. We also identified environmental thresholds where climate‐mediated selection is likely to be strong, and indicate that I. elegans is rapidly adapting to the climatic environment during its ongoing range expansion. Our findings empirically validate an integrative approach for detecting spatially explicit signatures of local adaptation along environmental gradients.
What a surprising development – who would have thought that species subject to selection pressure would simply evolve new survival strategies?