This post gives some important lessons the Guest Editor of the Genes Special Issue “Novel and Neglected Areas of Ancient DNA Research” has learned from his work.
Michael Hofreiter, who edits the Genes Special Issue “Novel and Neglected Areas of Ancient DNA Research”, states that the most important lesson he has learned from the genetics is that “operating on the assumption ‘sounds reasonable’ is never a good idea since I have seen time and again empirical data rejecting assumptions that had been based on this premise”.
In fact, he affirms that what counts in science are empirical data that are used to test a hypothesis, but regret that this principle is too often ignored, even in scientific work. Additionally, he highlights the importance of being cautious about hidden assumptions that often enough preset the result one gets from an analysis without the scientists performing the research (as well as editors and reviewers) even being aware of this.
Michael became interested in ancient DNA by accident when he studied for 6 months at the University of Aberdeen, where he did his first real lab work. Next he studied biology in Munich and started working on ancient DNA (from giant ground sloth faeces) and has never looked back.
After his experience in this field, he is completely convinced that with ancient DNA scientists can detect genetic lineages that have become extinct at some point in the past. This way they can document genetic changes in species (loss of diversity, turnover and replacement of populations, etc.) that could never be detected using modern DNA alone. An example for this is the North American brown bears, which had a completely different genetic makeup before the last glacial maximum compared to current populations.
From his point of view, “there are already many opportunities in this field, simply due to the fact that we are now able to reconstruct full genomes from fossil specimens”. This, Michael continues, “allows us to better understand many aspects of the evolution of both extinct and extant species”. Nevertheless, in this regard, he specifies that while it is a great time to work on ancient DNA, there are also challenges. Raising the money to obtain the data is one, as sequencing complete genomes from ancient DNA is still not a cheap endeavor.
Moreover, he considers another challenge that must be considered is not to inflict too much damage on the fossils – especially in work on human fossils. There has been a race between a number of groups, resulting in most paleo- and mesolithic human skulls having been drilled for ancient DNA samples by now.
Regarding the Special Issue he leads, he believes that it can help to diversify the scope of ancient DNA research as “we had quite a number of unusual studies in this field, which was the purpose of the topic we set”, but he is fully aware that he must be realistic and take into account that studies on humans will always attract more public attention and have a higher chance of being published in top-ranking journals than studies on more exotic species. However, he still hopes that “we had some success in pointing to the fact that this field exists of more than one species”.
Where his experience on the Genes Editorial Board and as a Guest Editor is concerned, he assures that is very positive given that “I only get requests that fit my competence, which is really nice for a change”. Indeed, in his view, “editing a Special Issue is always a mixed bag, because it is nice in the beginning when thinking about which articles would make good contributions and once it is done, but in between, it is always a fight to convince the authors one would like to have to agree on sending in a contribution and if they take this first step, convincing them to do so within the deadline”.
Michael is currently working on sequencing and analyzing genomes from a couple of species and species groups to better understand their evolution, including their long-term population size changes. Up until now, he has never had the feeling that he needs inspiration to follow up with his research, which is only driven “by being fascinated for one by all the strange creatures out there”.
Regarding this, he explains that in recent years, he has become more and more fascinated by the growing possibilities to study the evolution of life on earth, thanks to technical progress in many fields like sequencing technology, microscopy, computing power and many more. At this point, he mentions, for example, that there are hundreds of paleogenomes that have been sequenced by now and just ten years ago, most people were skeptical if we would ever be able to fully sequence any.
Finally, when it comes to his long-term research goal, he states that his objective is to gain a better understanding of how gene flow across space and time has shaped species’ evolution, both with regard to demography and adaptations. He would also like to know how often local populations go extinct and the habitat gets recolonized from a nearby (or distant) population and will enjoy his time finding out more about how species actually react to environmental changes in the long run. In this field, he points out how fast the species adapt and how important such changes in evolution are.