Recent landscape genomics studies in forest trees—what can we believe?

One of the key questions in evolutionary biology is how species adapt to novel climate changes. The first generation studies on different tree species presented a very first genomic step in a discovery of adaptive genes across different forest species. Most of them resulted in genes list with a diverse annotation functions however with lack of common ones, telling us each time a different evolutionary story. Although several studies have been conducted to explore an adaptive genetic potential in conifer species, a small proportion of novel putative genes was discovered. Similar, in case of Norway spruce, a genomic approach with 384 Illumina GoldenGate methodology, provided only a small insight of adaptation based on studies conducted so far. Mortality caused by drought and heat has been documented for Norway spruce as well as for other species across Europe proving its sensibility to the novel climatic conditions (Allen et al. 2009). We report that adaptive potential in Norway spruce has not been fully understood and it is unclear how evolutionary responses will be to the novel environmental conditions. We illustrate three explorative studies conducted so far on Norway spruce and summarize the proportion of discovered genes responsible for adaptive genetic potential and demonstrate the repeatability for these studies and observe the power of outlier detection methods used. Conclusively, exploratory studies on Norway spruce as well as other studies did not provide evidence of parallel or convergent evolution on molecular level within (closely related) species driving the confidence level down for the first generation studies.