Prologue
It began – as inwards so many stories – as an unlikely sequence of not-really connected events: a kind of accident. In my case: climate too cycads.It was 1999, too I exactly had handed inwards my Diplom thesis inwards geology-palaeontology (considered equivalent to a M.Sc., but normally substantially to a greater extent than than that, hence, took longer to get) entitled "Phylogenie der Cycadales" (phylogeny of the cycads: Grimm 1999; on my homepage, you'll discover html-Version [abstract inwards English], I hand-coded to a greater extent than than a decade back; footnotes are non working anymore).
 |
| The "coil" (a doodled phylogenetic tree), summarising the results of my Diplom-thesis |
 |
| The "best tree" found for my morphological information matrix. |
Mainly, I used literature to add together some fossil to an before morphological matrix too because of my background inwards genetics, I tried to acquire some genetic data. In a articulation effort, mainly thank y'all to the magic hands of my afterward (and at nowadays unfortunately dead) technician, Karin Stögerer – also known as "Karin leave of absence Hexe" (the Witch), because she did miracles alongside whatever textile – nosotros succeeded to acquire ii handful of cycad sequences roofing the variable D4 part of the nuclear-encoded 25S rRNA cistron added to some available inwards cistron banks to acquire a molecular tree. Naturally, the molecular-based too morphological tree were quite incongruent. Which should go the motto of my entire professional person scientific career: in that location is ever an alternative (tree).
 |
| The results of my "cladistic" analysis of the molecular data |
Act 1. And the Story of the Beech (the bitchy beast) commences
Our get-go coming together was a genuinely Livingstonian one. Thomas was told past times someone that his call appears as i of the authors of a poster on beech. Being curious why, he came to me standing at my poster (back then, poster presentation was dedicated its ain slot, so a lot of people would go around too compliment too encourage youngest researchers similar me for their work), smiling:"Hello, my call is Thomas Denk."
And I answered: "You are that Thomas Denk?!"
As it turned out, after he shipping his textile to Deutschland – he had collected beeches accross their entire gain inwards the wild for morphological studies (Denk 1999a, b, c) – he hadn't heard anything close whatever genetic results. And hither was a guy he never heard off, showing a molecular tree based on his material.
One argue for this was published inwards our get-go newspaper on beeches (Denk et al. 2002).
Evolution, in special the closer nosotros acquire to the leaves of the Tree of Life, is non treelike, but involves reticulation. Today too inwards the past. And nosotros had sequenced the so-called "ITS region", a non-coding but transcribed component of the nuclear-encoded 35 S rDNA cistron: a cistron part that encodes 3 of the 4 nuclear ribosomal RNAs, essential for all living organisms. It is inherited from both begetter (paternal) too woman nurture (maternal) too occurs inwards so-called tandem-repeats (adding upwards to the thousands per genome) inwards i or several so-called "Nucleolus Organizer Regions" (you discover some explanatory figures inwards e.g. Grimm et al. 2005), genetic particulars at the terminate of certainly chromosomes. Influenza A virus subtype H5N1 widely cited newspaper inwards 1993 or 1994 stated that a procedure called "concerted evolution" normally homogenises the many repeats across the genome, which was partly a prevarication already then. In many plants they are homogenised but inwards as many they are not, too sometimes y'all tin displace discover evidence of fifty-fifty ancient hybridisation. For beeches, nosotros were lucky to had opened a botanical Pandora's Box. And beingness a scientific serpent pit, people normally skipped organisms showing similar things than nosotros had inwards the beech trees.
 |
| When reticulation is a pretty trivial issue. ITS, 5S-IGS (a multicopy ribosomal spacer localised elsewhere inwards the genome), too LEAFY-i2 (a unmarried re-create nuclear intron; correct to left) genealogies inwards plane trees (genus Platanus, Grimm & Denk 2010). The dotted draw represents the evolutionary root of pseudogenic ITS copies inwards Platanus, also a outcome of ancient hybridisation between the "Pacific North American-European" (PNA-E) clade too the "Atlantic North American" (ANA) clade (Grimm & Denk 2008). |
For our get-go beech phylogeny paper, nosotros got ii short, half-page long reviewes past times anonymous (male) experts inwards the field, both suggesting that the newspaper should live rejected. The i said, our tree conflicts alongside before ones (using a dozen accessions, too all from botanical gardens), hence, must live wrong. The other, a palaeobotanist, said since nosotros don't demo a parsimony tree, which should live "standard" (the parsimonists had lost the so-called "phylogenetic wars" close 5 years earlier, but tidings move slower inwards palaeontology than neontology too inwards phytology compared to zoology, too he was both), all our results are naught.
Normally, the newspaper would receive got non been published, but our editor, a woman, recruited a 3rd anonymous reviewer (may receive got been a woman, too), who wrote a five-page long study pointing out all our many actual errors (mostly terminology, nosotros exactly followed what was published inwards phylogenetic literature, a bad guideline) but in conclusion that the results solitary would live worth publishing too is a must-publish for the journal. Influenza A virus subtype H5N1 tight call, fifty-fifty though nosotros had submitted our newspaper to a respectable, but low-impact mag (it has had quite an deport on despite of this).
Act 2. Grasping complexity of molecular development – a get-go phylogenetic framework for the beech
The beech trees too the maples would go the topic of my Ph.D. thesis: Tracing the Mode too Speed of Intrageneric Evolution (Grimm 2003, online 2005, open access), a piece of work that – to my cognition – only ii other persons read completely (and no native speaker, it should e.g. live "supported" whenever I wrote "sustained"): my 2nd supervisor, the geneticist (a woman) too some other adult woman (we regard a designing here, right?), who assisted the professor officially writing the external review. Back then, High German Ph.D.'s involved thesis reports past times your official supervisor, too some other faculty member, too in that location was a 1-hour private examine joined past times the dean inwards the in conclusion 5 or 10 minutes (in my case, nosotros had a goodness time, I was asked some questions too and then nosotros discussed essentially futurity projects). I needed an external 3rd reviewer, because #1 too #2 decided I should acquire a summa cum laude. (A German/continental thing, nosotros similar to grade, inwards the old times a "Summa", the best-possible grade, meant a certainly career, but similar all things, it lost its value.) We compiled more ITS information reflecting intra-individual too intra- too inter-specific variation. I pass a lot of fourth dimension looking at my alignment too started seeing the recurring mutational patterns. In the maples is was similar reading inwards a book; but inwards beech, most genetic differentiation was non fixing a mutation at a site, but gaining or loosing a intragenomic (intra-individual) site variation. Something, nosotros much afterward called "twisps" (2ISP; Potts et al. 2014). |
| Molecular development inwards the ITS of beech — gain too loss of mutation patterns at the intra-individual level, summed upwards for species too their probable fossil precursors (Grimm 2003; Denk, Grimm & Hemleben 2005, 2007). A, B etc. stand upwards for basic differentiation patterns |
Thanks to peer-review confidentiality, our get-go maple newspaper surfaced 3 years after my Ph.D. (Grimm et al. 2006). Our side past times side beech newspaper (Denk, Grimm & Hemleben 2005) alongside to a greater extent than information too a meliorate coverage of the other species, went smoothly (in a fashion) through the Forest of Reviews. We used Thomas' before morphological matrix (Denk 2003), added a few fossils, too compared it 1:1 alongside the molecular differentiation. To brand the reviewers (and readers) aware of the situation, what nosotros are looking at, I graphed some of the mutational patterns.
 |
| Selected differentiation patterns inwards the ITS of beech (figs 2–4 inwards Denk et al. 2005). Within species lineages consistent trends tin displace live observed, or increased variation including a portion type. This is how cistron pools evolve inwards a non-trivial case. |
The shadow-beasts inwards the Forest of Review growled over again — i negative ("reject") review too no other reviewer would respond to the editor's asking to review the paper. So, the editor read the newspaper himself, told us to to ignore the get-go review pretty much too provided a second, stating (in response to the reviewer's opinion) that he thinks "also negative results are worth publishing". Some editors exercise a swell job, fifty-fifty behind the Impermeable Fog. In our case, the – silent pretty unchallenged – only phylogenetic hypotheses available for the beech trees.
 |
| A summary of diverse phylogenetic inferences for beech trees. |
 |
| The extant (modern-day) too (hypothetical) fossil cistron pools of beech (modified after Grimm et al. 2005). Fossil taxa added inwards white font too placed according to their morphological affinity too spatio-temporal position. Grey circle too cyan, the ITS pools of the (south-central) Chinese species combining unique variants alongside variants shared or ancestral inside the subgenus Fagus (all but the lilac: F. evenensis, F. japonica, F. engleriana = Subgenus Engleriana). Genetically hayatae appeared having retained the master copy ITS variation. |
We before long realised beech species are inwards permanent flow. Reticulation beingness non uncommon, the province of affairs cannot live straight modelled using the criterion one-dimensional stick graphs, nosotros know as phylogenetic trees. Our study objects evidently had it all, cross-species messing, population dynamic effects, incongruent genealogies, "paralogy" (in a phylogenetic sense, pregnant that variants of the same molecule prefer different trees, non to live confused alongside genetic paralogues, which are the contrary of orthologues) etc. too nosotros had footling argue to assume that inwards the past times it was completely different. We had to bargain alongside the possibility that the beech may speciate too and then fuse over again when getting into contact, too that this is the argue for the complex ITS differentiation. And, non working alongside extremely rare private skeletons, but wide-spread, mutual macro- too microfossils, nosotros had to aspect that at to the lowest degree some of those fossils are the (direct) ancestors of the modern species.
 |
| Spatial too temporal distribution of fossil too modern beech species. Each acronym represents a species (morphospecies inwards the instance of fossils, "good" – morphologically too genetically coherent – species inwards the instance of modern-day taxa) too may stand upwards for a few finds or oftentimes establish fossils of the same type. E.g. inwards western Eurasia, the get-go evidence of beech trees coming from the East are Miocene F. castaneifolia (CAS; known also from the before Oligocene from Central Asia), which too then gradually alter into the younger F. haidingeri (HAI), which is too then replaced past times the modern-type F. sylvatica (SYL) morph inwards youngest strata. Modern-day F. sylvatica may (partly) live of mixed haidingeri-gussonii ancestry (GUS, a unique, hard to seat fossil establish in, too likely originating from Republic of Iceland or fifty-fifty North America, too western Mediterranean) or all derived from F. haidingeri. The ancient gain of F. haidingeri (and European F. gussonii) too modern gain of F. sylvatica are nearly identical. |
Welcome to the Dark Side of Phylogenetics. The dark realm, inwards which the much-cherished vivid sunlight of cladistics – y'all exactly infer a one-dimensional stick graph, too this tells y'all all y'all demand to know close development – diminishes into an ephemeral draw at the horizon.
Act 3. Stepping out of the comfort zone into the past times
Despite the genetic chaos (to some degree) too alongside a footling training, anyone tin displace seat the few by too large accepted species inwards nature (good species inwards accordance alongside Mallet's object-orientated solution to the species question). With to a greater extent than preparation too insights y'all tin displace fifty-fifty realise that nosotros receive got 3 or 4 contemporary species inwards western Eurasia, too non i (Denk 1999b,c; Gömöry & Paule 2010). We never establish nonetheless the muse to formalise this.Thus, i could brand a morphology-based tree that made feel at the fourth dimension (Denk 2003), but linking that tree alongside the genetics of the genus (Denk et al. 2005) made things non easier. Especially when nosotros started to add together fossils, including some that may live ancestors of others (and modern-day species). Something the classical trees (and Farrisian cladistics) only cannot grip (we did fifty-fifty tried explicit biogeographic inferences, but their results were completely for the bin). We moved on to networks too exploratory information analysis (EDA; Denk & Grimm 2009).
EDA is something, I never had heard anything close before I learned close the Genealogical World of Phylogenetic Networks (GWoN) too met David Morrison close 5 years later, when he came visiting me to regard alongside his ain eyes the footling heretic sitting at Farris' ain institution. But fifty-fifty ignorant of what EDA means, I had been doing it since my Diplom thesis. Influenza A virus subtype H5N1 flake belatedly (and besides belatedly for me to remain inwards professional person science), but it was goodness to know, I was non travelling a totally obscure path, but i that had been taken past times others a goodness fourth dimension before me.
Networks are a natural alternative for morphological data, too information sets including fossils (see e.g. posts on GWoN). When I was silent inwards Tübingen, a boyfriend mycologist, Markus Göker, pointed me to a newspaper inwards the Journal of Theoretical Biology past times I'm non the only one: modern-day cladistics is inwards essence a much afterward (late 70s, early on 80s) innovation past times Steve Farris too other figureheads inwards the Willi Hennig Society. In my parallel studies for a biology-Diplom, I had specialised inwards genetics too zoology (of course) during graduate courses (but I never did my Großpraktikum – at to the lowest degree one-half a twelvemonth of largely self-responsible laboratory experimentation too thus never handed inwards whatever Diplom-theses, so I can't boost alongside a 2nd academic title: inwards the electrical flow anglo-saxonised High German system, I would fulfil the qualifications for 3 B.Sc. (chemistry, geology, too biology) too ii M.Sc. (palaeontology too genetics), but I likely couldn't receive got done what I did dorsum inwards the goodness old days: follow my interests too curiosities.
|
| The "best tree" found for my morphological information matrix. |
Mainly, I used literature to add together some fossil to an before morphological matrix too because of my background inwards genetics, I tried to acquire some genetic data. In a articulation effort, mainly thank y'all to the magic hands of my afterward (and at nowadays unfortunately dead) technician, Karin Stögerer – also known as "Karin leave of absence Hexe" (the Witch), because she did miracles alongside whatever textile – nosotros succeeded to acquire ii handful of cycad sequences roofing the variable D4 part of the nuclear-encoded 25S rRNA cistron added to some available inwards cistron banks to acquire a molecular tree. Naturally, the molecular-based too morphological tree were quite incongruent. Which should go the motto of my entire professional person scientific career: in that location is ever an alternative (tree).
|
| The results of my "cladistic" analysis of the molecular data |
Act 1. And the Story of the Beech (the bitchy beast) commences
Our get-go coming together was a genuinely Livingstonian one. Thomas was told past times someone that his call appears as i of the authors of a poster on beech. Being curious why, he came to me standing at my poster (back then, poster presentation was dedicated its ain slot, so a lot of people would go around too compliment too encourage youngest researchers similar me for their work), smiling:"Hello, my call is Thomas Denk."
And I answered: "You are that Thomas Denk?!"
As it turned out, after he shipping his textile to Deutschland – he had collected beeches accross their entire gain inwards the wild for morphological studies (Denk 1999a, b, c) – he hadn't heard anything close whatever genetic results. And hither was a guy he never heard off, showing a molecular tree based on his material.
One argue for this was published inwards our get-go newspaper on beeches (Denk et al. 2002).
Evolution, in special the closer nosotros acquire to the leaves of the Tree of Life, is non treelike, but involves reticulation. Today too inwards the past. And nosotros had sequenced the so-called "ITS region", a non-coding but transcribed component of the nuclear-encoded 35 S rDNA cistron: a cistron part that encodes 3 of the 4 nuclear ribosomal RNAs, essential for all living organisms. It is inherited from both begetter (paternal) too woman nurture (maternal) too occurs inwards so-called tandem-repeats (adding upwards to the thousands per genome) inwards i or several so-called "Nucleolus Organizer Regions" (you discover some explanatory figures inwards e.g. Grimm et al. 2005), genetic particulars at the terminate of certainly chromosomes. Influenza A virus subtype H5N1 widely cited newspaper inwards 1993 or 1994 stated that a procedure called "concerted evolution" normally homogenises the many repeats across the genome, which was partly a prevarication already then. In many plants they are homogenised but inwards as many they are not, too sometimes y'all tin displace discover evidence of fifty-fifty ancient hybridisation. For beeches, nosotros were lucky to had opened a botanical Pandora's Box. And beingness a scientific serpent pit, people normally skipped organisms showing similar things than nosotros had inwards the beech trees.
|
| When reticulation is a pretty trivial issue. ITS, 5S-IGS (a multicopy ribosomal spacer localised elsewhere inwards the genome), too LEAFY-i2 (a unmarried re-create nuclear intron; correct to left) genealogies inwards plane trees (genus Platanus, Grimm & Denk 2010). The dotted draw represents the evolutionary root of pseudogenic ITS copies inwards Platanus, also a outcome of ancient hybridisation between the "Pacific North American-European" (PNA-E) clade too the "Atlantic North American" (ANA) clade (Grimm & Denk 2008). |
For our get-go beech phylogeny paper, nosotros got ii short, half-page long reviewes past times anonymous (male) experts inwards the field, both suggesting that the newspaper should live rejected. The i said, our tree conflicts alongside before ones (using a dozen accessions, too all from botanical gardens), hence, must live wrong. The other, a palaeobotanist, said since nosotros don't demo a parsimony tree, which should live "standard" (the parsimonists had lost the so-called "phylogenetic wars" close 5 years earlier, but tidings move slower inwards palaeontology than neontology too inwards phytology compared to zoology, too he was both), all our results are naught.
Normally, the newspaper would receive got non been published, but our editor, a woman, recruited a 3rd anonymous reviewer (may receive got been a woman, too), who wrote a five-page long study pointing out all our many actual errors (mostly terminology, nosotros exactly followed what was published inwards phylogenetic literature, a bad guideline) but in conclusion that the results solitary would live worth publishing too is a must-publish for the journal. Influenza A virus subtype H5N1 tight call, fifty-fifty though nosotros had submitted our newspaper to a respectable, but low-impact mag (it has had quite an deport on despite of this).
Act 2. Grasping complexity of molecular development – a get-go phylogenetic framework for the beech
The beech trees too the maples would go the topic of my Ph.D. thesis: Tracing the Mode too Speed of Intrageneric Evolution (Grimm 2003, online 2005, open access), a piece of work that – to my cognition – only ii other persons read completely (and no native speaker, it should e.g. live "supported" whenever I wrote "sustained"): my 2nd supervisor, the geneticist (a woman) too some other adult woman (we regard a designing here, right?), who assisted the professor officially writing the external review. Back then, High German Ph.D.'s involved thesis reports past times your official supervisor, too some other faculty member, too in that location was a 1-hour private examine joined past times the dean inwards the in conclusion 5 or 10 minutes (in my case, nosotros had a goodness time, I was asked some questions too and then nosotros discussed essentially futurity projects). I needed an external 3rd reviewer, because #1 too #2 decided I should acquire a summa cum laude. (A German/continental thing, nosotros similar to grade, inwards the old times a "Summa", the best-possible grade, meant a certainly career, but similar all things, it lost its value.) We compiled more ITS information reflecting intra-individual too intra- too inter-specific variation. I pass a lot of fourth dimension looking at my alignment too started seeing the recurring mutational patterns. In the maples is was similar reading inwards a book; but inwards beech, most genetic differentiation was non fixing a mutation at a site, but gaining or loosing a intragenomic (intra-individual) site variation. Something, nosotros much afterward called "twisps" (2ISP; Potts et al. 2014). |
| Molecular development inwards the ITS of beech — gain too loss of mutation patterns at the intra-individual level, summed upwards for species too their probable fossil precursors (Grimm 2003; Denk, Grimm & Hemleben 2005, 2007). A, B etc. stand upwards for basic differentiation patterns |
Thanks to peer-review confidentiality, our get-go maple newspaper surfaced 3 years after my Ph.D. (Grimm et al. 2006). Our side past times side beech newspaper (Denk, Grimm & Hemleben 2005) alongside to a greater extent than information too a meliorate coverage of the other species, went smoothly (in a fashion) through the Forest of Reviews. We used Thomas' before morphological matrix (Denk 2003), added a few fossils, too compared it 1:1 alongside the molecular differentiation. To brand the reviewers (and readers) aware of the situation, what nosotros are looking at, I graphed some of the mutational patterns.
|
| Selected differentiation patterns inwards the ITS of beech (figs 2–4 inwards Denk et al. 2005). Within species lineages consistent trends tin displace live observed, or increased variation including a portion type. This is how cistron pools evolve inwards a non-trivial case. |
The shadow-beasts inwards the Forest of Review growled over again — i negative ("reject") review too no other reviewer would respond to the editor's asking to review the paper. So, the editor read the newspaper himself, told us to to ignore the get-go review pretty much too provided a second, stating (in response to the reviewer's opinion) that he thinks "also negative results are worth publishing". Some editors exercise a swell job, fifty-fifty behind the Impermeable Fog. In our case, the – silent pretty unchallenged – only phylogenetic hypotheses available for the beech trees.
|
| A summary of diverse phylogenetic inferences for beech trees. |
|
| The extant (modern-day) too (hypothetical) fossil cistron pools of beech (modified after Grimm et al. 2005). Fossil taxa added inwards white font too placed according to their morphological affinity too spatio-temporal position. Grey circle too cyan, the ITS pools of the (south-central) Chinese species combining unique variants alongside variants shared or ancestral inside the subgenus Fagus (all but the lilac: F. evenensis, F. japonica, F. engleriana = Subgenus Engleriana). Genetically hayatae appeared having retained the master copy ITS variation. |
We before long realised beech species are inwards permanent flow. Reticulation beingness non uncommon, the province of affairs cannot live straight modelled using the criterion one-dimensional stick graphs, nosotros know as phylogenetic trees. Our study objects evidently had it all, cross-species messing, population dynamic effects, incongruent genealogies, "paralogy" (in a phylogenetic sense, pregnant that variants of the same molecule prefer different trees, non to live confused alongside genetic paralogues, which are the contrary of orthologues) etc. too nosotros had footling argue to assume that inwards the past times it was completely different. We had to bargain alongside the possibility that the beech may speciate too and then fuse over again when getting into contact, too that this is the argue for the complex ITS differentiation. And, non working alongside extremely rare private skeletons, but wide-spread, mutual macro- too microfossils, nosotros had to aspect that at to the lowest degree some of those fossils are the Spencer et al. (2004). Later, nosotros teamed upwards for some pretty heretic papers, i providing the get-go individual-based genetic network of beeches too a solution to the ITS variation job past times using a “host-associate” framework (Göker & Grimm 2008); some other an alignment-free way to define cryptic species inwards planktic foramifers (Göker et al. 2010) — y'all know, things mycologists too geno-geologists typically squad upwards for.
Spencer et al. establish that the Neighbour-net (Bryant & Moulton 2002, 2004), a planar (2-dimensional) distance-based (meta)phylogenetic graph, outperforms all tree-based inference method when it comes to actual ancestor-descendant relationships. Due to my analysis of genetic information inwards beeches (and maples, too and then oaks, Denk & Grimm 2010) too the sheer coincidence that Daniel Huson, the programmer of SplitsTree, got a professorship inwards Tübingen sitting inwards the same edifice than the hubby of my boss, I knew close the potential of consensus networks to visualise internal information conflict too topological alternative. Just from the spatio-temporal distribution of beech fossils (map above), it is pretty obvious that some fossil morphotypes stand upwards for precursors (and probable direct ancestors) of i or to a greater extent than modern-day species, others are similar but harder to place. Neighbour-nets too "bipartition networks" (Grimm et al. 2006), meliorate labelled back upwards consensus networks (Schliep et al. 2017), seemed a natural choice.
 |
| A morpho-distance-based (meta)phylogenetic network of living too (long) dead beech species. Fossil taxa represented past times opened upwards circles, modern-day ones filled. The acronyms too colours refer to geographic units (in fourth dimension too space), including lost ones: BER = Beringia, ISL = Iceland, too PNA = Pacific North America |
The 2009 newspaper remains a pretty unique slice until today, a decade later, as it used distance-based morphology-based planar (meta)phylogenetic networks (above), back upwards consensus networks based on parsimony bootstrap replicates too Bayesian-inferred tree samples (example below), too in conclusion but non to the lowest degree "distance suns" too other uncomplicated graphs visualising morphological change.
   |
| Four graphs visualising variety too potential relationships betwixt fossil too modern beech species. Knowing all aspects of your information tin displace live the key for putting upwards a holistic evolutionary framework. |
All these explicit, data-based analyses were rounded upwards past times the considerable cognition of Thomas, the actual palaeobotanist inwards our 2-man team, close the fossil record, morphological alter too variation, too allowed us to come upwards up alongside a pretty neat history of the genus through infinite too time. 2009, the oldest beech fossil (i.e. representing Fagus, the modern genus) was Fagus langevinii from the spectacular, c. 50 Ma old McAbee Flora, which has all characteristics of a modern-day beech. Recently, my colleagues inwards Vienna establish an close 10 Ma older Fagus pollen inwards in-situ formed nodules embedded inwards an absolutely dated strata of the "Hare Island" inwards the Disco Bay, western Greenland (Grímsson et al. 2016; molecular information predicted that the lineage comprising Fagus latest evolved inwards the Late Cretaceous, fourscore Ma ago, but all Fagaceae/Fagales dating so far receive got been fundamentally flawed, regard below).
 |
| Earliest fossil tape of Fagus — A high-latitude wood species spreads into the palaeomountains of Pacific North America too across Beringia into North-east Asia. This too all next background maps are custom-tilted Molleweide projections past times Ron Blakey (©) that he provided for our 2009 newspaper (standard-oriented projections tin displace live establish inwards Blakey 2008). |
 |
| The Oligocene cooling — perfect for "nemoral" (fully humid, warm temperate to boreal; Köppen zones Cfa, Cfb, too Dfb) chemical component to expand across Eurasia too go downwardly the North American Pacific coast. And differentiate into a continental Eurasian (orange) too northern Pacific (red) lineage. |
 |
| The Miocene, a fourth dimension of speciation too (incomplete) lineage sorting. A novel type evolves inwards western Eurasia (yellow), successively replacing the ancient orangish lineage, too re-migrating to Japan. The orangish lineage survives inwards China. Influenza A virus subtype H5N1 morphologically (and today genetically) most distinct novel lineage emerges inwards North-east Asia from the Pacific pool: the "Subgenus Engleriana" (pink). An isolated shape (black, GUS) alongside no clear affinities, spreads from Republic of Iceland into western Europe, too some other (brown) is establish inwards Central Asia. |
 |
| Pleistocene (glacial maximum shown inwards the map) to now. The western Eurasian lineages gets separated from its Japanese sis (morphologically too genetically, modern-day F. crenata, CRE, too F. sylvatica, SYL, are silent really similar). The ancient orangish morphs live inwards genetically dimorphic Chinese species (evidence for subrecent reticulation), as good as the unique type (brown) from Central Asia. The master copy Pacific lineage (red) vanishes inwards East Asia, but survives inwards the perhumid warm/hot summertime zone of eastern North America (with an outpost inwards similar climate pockets inwards interior Mexico). Possibly the carmine Asian went extinct, or were dissolved inwards the surviving lineages. Modern-day individuals of the pinkish species demo ii or 3 highly divergent ITS copies, whereas the modern-day yellowish (F. crenata) appears to live really homogenous. [Fun fact: plastid signatures, representing only the maternal lineage, beech seeds are heavy things, the principal designing y'all regard is East Asia, western Eurasia, or North America. The same haplotypes are establish inwards pinkish F. japonica and yellowish F. crenata.] |
Act 4. (Tree-based) "clocks" too "rocks" unite
For us, too for science, this appeared to live the terminate of the story. I lost my technician too lab when I had to leave of absence Deutschland inwards 2008 (to "develop my career past times gaining international experience", as the High German Science Foundation seat it), so nosotros had no resources to exercise anything anymore. Based on what nosotros found, too what readily go obvious past times before too afterward species-level studies on the plastids (little species correlation, exactly provenance; as inwards their distant sis genus, the oaks), no-one would cite the task of producing to a greater extent than cistron information to proof us incorrect or cite from where nosotros left. It's "publish or perish" inwards professional person science, too complex situations require much to a greater extent than investment than trivial ones, alongside less output (and, often, to a greater extent than annoyance during the so-called I'm non the only one: modern-day cladistics is inwards essence a much afterward (late 70s, early on 80s) innovation past times Steve Farris too other figureheads inwards the Willi Hennig Society. In my parallel studies for a biology-Diplom, I had specialised inwards genetics too zoology (of course) during graduate courses (but I never did my Großpraktikum – at to the lowest degree one-half a twelvemonth of largely self-responsible laboratory experimentation too thus never handed inwards whatever Diplom-theses, so I can't boost alongside a 2nd academic title: inwards the electrical flow anglo-saxonised High German system, I would fulfil the qualifications for 3 B.Sc. (chemistry, geology, too biology) too ii M.Sc. (palaeontology too genetics), but I likely couldn't receive got done what I did dorsum inwards the goodness old days: follow my interests too curiosities. |
| The "best tree" found for my morphological information matrix. |
Mainly, I used literature to add together some fossil to an before morphological matrix too because of my background inwards genetics, I tried to acquire some genetic data. In a articulation effort, mainly thank y'all to the magic hands of my afterward (and at nowadays unfortunately dead) technician, Karin Stögerer – also known as "Karin leave of absence Hexe" (the Witch), because she did miracles alongside whatever textile – nosotros succeeded to acquire ii handful of cycad sequences roofing the variable D4 part of the nuclear-encoded 25S rRNA cistron added to some available inwards cistron banks to acquire a molecular tree. Naturally, the molecular-based too morphological tree were quite incongruent. Which should go the motto of my entire professional person scientific career: in that location is ever an alternative (tree).
|
| The results of my "cladistic" analysis of the molecular data |
Act 1. And the Story of the Beech (the bitchy beast) commences
Our get-go coming together was a genuinely Livingstonian one. Thomas was told past times someone that his call appears as i of the authors of a poster on beech. Being curious why, he came to me standing at my poster (back then, poster presentation was dedicated its ain slot, so a lot of people would go around too compliment too encourage youngest researchers similar me for their work), smiling:"Hello, my call is Thomas Denk."
And I answered: "You are that Thomas Denk?!"
As it turned out, after he shipping his textile to Deutschland – he had collected beeches accross their entire gain inwards the wild for morphological studies (Denk 1999a, b, c) – he hadn't heard anything close whatever genetic results. And hither was a guy he never heard off, showing a molecular tree based on his material.
One argue for this was published inwards our get-go newspaper on beeches (Denk et al. 2002).
Evolution, in special the closer nosotros acquire to the leaves of the Tree of Life, is non treelike, but involves reticulation. Today too inwards the past. And nosotros had sequenced the so-called "ITS region", a non-coding but transcribed component of the nuclear-encoded 35 S rDNA cistron: a cistron part that encodes 3 of the 4 nuclear ribosomal RNAs, essential for all living organisms. It is inherited from both begetter (paternal) too woman nurture (maternal) too occurs inwards so-called tandem-repeats (adding upwards to the thousands per genome) inwards i or several so-called "Nucleolus Organizer Regions" (you discover some explanatory figures inwards e.g. Grimm et al. 2005), genetic particulars at the terminate of certainly chromosomes. Influenza A virus subtype H5N1 widely cited newspaper inwards 1993 or 1994 stated that a procedure called "concerted evolution" normally homogenises the many repeats across the genome, which was partly a prevarication already then. In many plants they are homogenised but inwards as many they are not, too sometimes y'all tin displace discover evidence of fifty-fifty ancient hybridisation. For beeches, nosotros were lucky to had opened a botanical Pandora's Box. And beingness a scientific serpent pit, people normally skipped organisms showing similar things than nosotros had inwards the beech trees.
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| When reticulation is a pretty trivial issue. ITS, 5S-IGS (a multicopy ribosomal spacer localised elsewhere inwards the genome), too LEAFY-i2 (a unmarried re-create nuclear intron; correct to left) genealogies inwards plane trees (genus Platanus, Grimm & Denk 2010). The dotted draw represents the evolutionary root of pseudogenic ITS copies inwards Platanus, also a outcome of ancient hybridisation between the "Pacific North American-European" (PNA-E) clade too the "Atlantic North American" (ANA) clade (Grimm & Denk 2008). |
For our get-go beech phylogeny paper, nosotros got ii short, half-page long reviewes past times anonymous (male) experts inwards the field, both suggesting that the newspaper should live rejected. The i said, our tree conflicts alongside before ones (using a dozen accessions, too all from botanical gardens), hence, must live wrong. The other, a palaeobotanist, said since nosotros don't demo a parsimony tree, which should live "standard" (the parsimonists had lost the so-called "phylogenetic wars" close 5 years earlier, but tidings move slower inwards palaeontology than neontology too inwards phytology compared to zoology, too he was both), all our results are naught.
Normally, the newspaper would receive got non been published, but our editor, a woman, recruited a 3rd anonymous reviewer (may receive got been a woman, too), who wrote a five-page long study pointing out all our many actual errors (mostly terminology, nosotros exactly followed what was published inwards phylogenetic literature, a bad guideline) but in conclusion that the results solitary would live worth publishing too is a must-publish for the journal. Influenza A virus subtype H5N1 tight call, fifty-fifty though nosotros had submitted our newspaper to a respectable, but low-impact mag (it has had quite an deport on despite of this).
Act 2. Grasping complexity of molecular development – a get-go phylogenetic framework for the beech
The beech trees too the maples would go the topic of my Ph.D. thesis: Tracing the Mode too Speed of Intrageneric Evolution (Grimm 2003, online 2005, open access), a piece of work that – to my cognition – only ii other persons read completely (and no native speaker, it should e.g. live "supported" whenever I wrote "sustained"): my 2nd supervisor, the geneticist (a woman) too some other adult woman (we regard a designing here, right?), who assisted the professor officially writing the external review. Back then, High German Ph.D.'s involved thesis reports past times your official supervisor, too some other faculty member, too in that location was a 1-hour private examine joined past times the dean inwards the in conclusion 5 or 10 minutes (in my case, nosotros had a goodness time, I was asked some questions too and then nosotros discussed essentially futurity projects). I needed an external 3rd reviewer, because #1 too #2 decided I should acquire a summa cum laude. (A German/continental thing, nosotros similar to grade, inwards the old times a "Summa", the best-possible grade, meant a certainly career, but similar all things, it lost its value.) We compiled more ITS information reflecting intra-individual too intra- too inter-specific variation. I pass a lot of fourth dimension looking at my alignment too started seeing the recurring mutational patterns. In the maples is was similar reading inwards a book; but inwards beech, most genetic differentiation was non fixing a mutation at a site, but gaining or loosing a intragenomic (intra-individual) site variation. Something, nosotros much afterward called "twisps" (2ISP; Potts et al. 2014). |
| Molecular development inwards the ITS of beech — gain too loss of mutation patterns at the intra-individual level, summed upwards for species too their probable fossil precursors (Grimm 2003; Denk, Grimm & Hemleben 2005, 2007). A, B etc. stand upwards for basic differentiation patterns |
Thanks to peer-review confidentiality, our get-go maple newspaper surfaced 3 years after my Ph.D. (Grimm et al. 2006). Our side past times side beech newspaper (Denk, Grimm & Hemleben 2005) alongside to a greater extent than information too a meliorate coverage of the other species, went smoothly (in a fashion) through the Forest of Reviews. We used Thomas' before morphological matrix (Denk 2003), added a few fossils, too compared it 1:1 alongside the molecular differentiation. To brand the reviewers (and readers) aware of the situation, what nosotros are looking at, I graphed some of the mutational patterns.
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| Selected differentiation patterns inwards the ITS of beech (figs 2–4 inwards Denk et al. 2005). Within species lineages consistent trends tin displace live observed, or increased variation including a portion type. This is how cistron pools evolve inwards a non-trivial case. |
The shadow-beasts inwards the Forest of Review growled over again — i negative ("reject") review too no other reviewer would respond to the editor's asking to review the paper. So, the editor read the newspaper himself, told us to to ignore the get-go review pretty much too provided a second, stating (in response to the reviewer's opinion) that he thinks "also negative results are worth publishing". Some editors exercise a swell job, fifty-fifty behind the Impermeable Fog. In our case, the – silent pretty unchallenged – only phylogenetic hypotheses available for the beech trees.
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| A summary of diverse phylogenetic inferences for beech trees. |
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| The extant (modern-day) too (hypothetical) fossil cistron pools of beech (modified after Grimm et al. 2005). Fossil taxa added inwards white font too placed according to their morphological affinity too spatio-temporal position. Grey circle too cyan, the ITS pools of the (south-central) Chinese species combining unique variants alongside variants shared or ancestral inside the subgenus Fagus (all but the lilac: F. evenensis, F. japonica, F. engleriana = Subgenus Engleriana). Genetically hayatae appeared having retained the master copy ITS variation. |
We before long realised beech species are inwards permanent flow. Reticulation beingness non uncommon, the province of affairs cannot live straight modelled using the criterion one-dimensional stick graphs, nosotros know as phylogenetic trees. Our study objects evidently had it all, cross-species messing, population dynamic effects, incongruent genealogies, "paralogy" (in a phylogenetic sense, pregnant that variants of the same molecule prefer different trees, non to live confused alongside genetic paralogues, which are the contrary of orthologues) etc. too nosotros had footling argue to assume that inwards the past times it was completely different. We had to bargain alongside the possibility that the beech may speciate too and then fuse over again when getting into contact, too that this is the argue for the complex ITS differentiation. And, non working alongside extremely rare private skeletons, but wide-spread, mutual macro- too microfossils, nosotros had to aspect that at to the lowest degree some of those fossils are the "confidential single-blind peer review" process). Also, it is beneficial if researchers alongside different backgrounds piece of work together, which is besides rarely the case, inwards existent too non only past times sharing co-authorships on papers.
But it was not.
Magical 7 years later, nosotros had the chance to expose (Renner et al. 2016) an explicit molecular dating experiment (and yet over again updated fossil tape past times my veteran co-author Thomas Denk) finding that everything matches upwards astonishingly well. With footling resources, hence, few genes, but silent a dainty piece. Being i of the rare dating studies inwards phytology that demonstrate the importance of cross-disciplinary enquiry too inter-disciplinary information sets to span the artificial gap normally seen too much highlighted inwards diverse papers: besides immature clocks, besides old fossils.
Even when y'all too then discover novel (and older fossils, Grímsson et al. 2016; the dating newspaper was submitted too done, when my novel colleagues inwards Vienna people establish their pollen).
 |
| Perfect tally — the novel ancient pollen described inwards Grimsson inwards et al. (2016) inwards relation to the (bit) before chronogram past times Renner et al. (2016) that recruited the revised too updated fossil tape for a fossilised birth-death dating of the genus (Heath, Huelsenbeck & Stadler 2014). |
There is no discrepancy betwixt "clocks" too "rocks", when the "rock" component is good understood or selected alongside attention when it comes to the "clock". It may live a bold statement, but I would recall that all besides immature molecular dating estimates too most "long-distance" dispersal would receive got non been published or seat frontward as results, if knowledged palaeobotanists would receive got actively contributed to or reviewed these papers. Or if molecular phylogeneticists too bioinformaticians would piece of work for palaeontologists (like I did); too start adressing the many elephants inwards the room.
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| Summarised footing of Fagales/Fagaceae (order too draw of piece of work solid unit of measurement including beeches) node dating studies done inwards the in conclusion vi years. Shown are the topologies used for the diverse dating studies, the branch back upwards (bootstrap back upwards for A, otherwise Bayesian posterior probabilities), too the used fossil historic catamenia constraints (same fossil, same colour). Totally surprising: everyone got different ages except for as constrained nodes (from Grímsson et al. 2016; online supporting material). |
Epilogue: The end?
For me, it is. I'm non a professional person scientist anymore. The gamble is that it volition bring a decade or to a greater extent than till the side past times side measuring ahead is done. But in that location is plenty to do.First, somebody should generate to a greater extent than nuclear data, too regard if it changes something for the (fossilised birth-death) dating. Some of our estimates for within-genus diversification appear to live a flake old too our information laid was a compromise due to lack of resources. When y'all exercise so, y'all receive got to rely on textile collected inwards the wild; arboretum trees volition Pb y'all nix unopen to reality. For phylogeny inwards (extratropical) Fagaceae, y'all demand nuclear data; plastid genealogies are interesting, also for comparing too testing ancient reticulation scenarios, but solely decoupled from the speciation processes inwards the past: the evolutionary unfolding of the genus inwards infinite too time.
Second, somebody should formalise the actual species establish inwards western Eurasia, which is quite a nasty piece of work (long synonymy lists, too a lot of dusty piece of work figuring out, which call would live valid or if a novel call needs to live coined). Data-wise everything is clear, in that location are geographic too genetic-morphological coherent groups inside what is these all called Fagus sylvatica (literally "Forest Beech", but known as Common Beech or Rotbuche, "Red Beech").
Third, too to the lowest degree likely*, some people could brand an opened upwards access database including whatever revised Fagus fossil, so i could brand details maps of the distribution inwards the past.
Which other industrial plant life genus has such a goodness footing to start from? Let me conclude alongside a High German proverb, a non actually goodness proposition what to exercise inwards instance of thunderstorms to avoid beingness stroke downwardly past times lightning.
Buchen sollst du suchen; vor Eichen, sollst du weichen!
(translation: Look out for beeches, too avoid the oaks; Thomas too I were lucky to bargain alongside both ...)
* Least likely, because universities too enquiry institutes dealing inwards biodiversity too development silent hire molecular systematicists (obsolete these days, the only thing y'all demand is i bioinformatician) instead of champaign botanists (needed to get together proper material) too palaeobotanists (needed to exercise the non-automatable piece of work needed to acquire goodness palaeontological data. Influenza A virus subtype H5N1 perfectly staffed phylogenetic subdivision has 3 (proper) zoologists, vi botanists, too i bioinformatician for analysing the information the other nine produce. Why double as much botanists than zoologists? Plants are normally trickier too challenging than animals (for a start, y'all normally demand to study much to a greater extent than individuals), too much less good studied for at nowadays over 150 years. That is why y'all receive got a highly detailed Mesozoic Tree of Life on the brute side, but nix comparable on the much to a greater extent than mutual co-eval plants that a goodness bargain of the really few establish dinosaurs thrived on. When y'all receive got to increment the number of zoologists (typically it'd live 6:3 or worse for the phytology side), bring those that piece of work alongside mutual animals (invertebrates).
Cited literature
(Mostly our ain papers, I'm afraid. Even though it is i of the most economically too ecologically of import tree genera inwards the extratropical Northern Hemisphere too has less than 10 species, too a fine fossil record, it never got much attending past times phylogeneticists too palaeobotanists. 10 may non live plenty to aspect into...)
Blakey RC. 2008. Gondwana paleogeography from assembly to breakup—A 500 m.y. odyssey. In: Fielding CR, Frank TD, too Isbell JL, eds. Resolving the Late Paleozoic Ice Age inwards Time too Space. Boulder: Geological Society of America, p. 1–28.
Bryant D, Moulton V. 2002. NeighborNet: an agglomerative method for the structure of planar phylogenetic networks. In: Guigó R, too Gusfield D, eds. Algorithms inwards Bioinformatics, Second International Workshop, WABI. Rome, Italy: Springer Verlag, Berlin, Heidelberg, New York, p. 375-391.
Bryant D, Moulton V. 2004. Neighbor-Net: An agglomerative method for the structure of phylogenetic networks. Molecular Biology too Evolution 21:255-265.
Denk T. 1999a. The taxonomy of Fagus in western Eurasia too the ancestors of Fagus sylvatica s.l. Acta Palaeobotanica Supplement 2:633-641.
Denk T. 1999b. The taxonomy of Fagus in western Eurasia, 1: Fagus sylvatica subsp. orientalis (= F. orientalis). Feddes Repertorium 110:177-200.
Denk T. 1999c. The taxonomy of Fagus in western Eurasia, 2: Fagus sylvatica subsp. sylvatica. Feddes Repertorium 110:381-412.
Denk T. 2003. Phylogeny of Fagus L. (Fagaceae) based on morphological data. Plant Systematics too Evolution 240:55-81.
Denk T, Grimm G, Stögerer K, Langer M, Hemleben V. 2002. The evolutionary history of Fagus in western Eurasia: Evidence from genes, morphology too the fossil record. Plant Systematics too Evolution 232:213-236.
Denk T, Grimm GW. 2009. The biogeographic history of beech trees. Review of Palaeobotany too Palynology 158:83–100.
Denk T, Grimm GW. 2010. The oaks of western Eurasia: traditional classifications too evidence from ii nuclear markers. Taxon 59:351–366.
Denk T, Grimm GW, Hemleben V. 2005. Patterns of molecular too morphological differentiation inwards Fagus: implications for phylogeny. American Journal of Botany 92:1006-1016.
Göker M, Grimm GW. 2008. General functions to transform associate information to host data, too their work inwards phylogenetic inference from sequences alongside intra-individual variability. BMC Evolutionary Biology 8:86.
Göker M, Grimm GW, Auch AF, Aurahs R, Kučera M. 2010. Influenza A virus subtype H5N1 clustering optimization strategy for molecular taxonomy too its application to planktonic foraminifera SSU rDNA. Evolutionary Bioinformatics 6:97–112.
Gömöry D, Paule L. 2010. Reticulate development patterns inwards western-Eurasian beeches. Botanica Helvetica 120:63–74.
Grimm GW. 1999. Phylogenie der Cycadales. Diploma thesis thesis. Eberhard-Karls Universität, Tübingen.
Grimm GW. 2003. Tracing the way too speed of intrageneric development - a instance study of genus Acer L. too Fagus L. D.Sc. thesis. Eberhard-Karls University.
Grimm GW, Denk T. 2008. ITS development inwards Platanus: homoeologues, pseudogenes, too ancient hybridization. Annals of Botany 101:403-419.
Grimm GW, Denk T. 2010. The reticulate root of modern plane trees (Platanus, Platanaceae) - a nuclear mark puzzle. Taxon 59:134-147.
Grimm GW, Denk T, Hemleben V. 2007. Coding of intraspecific nucleotide polymorphisms: a tool to resolve reticulate evolutionary relationships inwards the ITS of beech trees (Fagus L., Fagaceae). Systematics too Biodiversity 5:291-309.
Grimm GW, Renner SS, Stamatakis A, Hemleben V. 2006. Influenza A virus subtype H5N1 nuclear ribosomal deoxyribonucleic acid phylogeny of Acer inferred alongside maximum likelihood, splits graphs, too motif analyses of 606 sequences. Evolutionary Bioinformatics 2:279–294.
Grimm GW, Schlee M, Komarova NY, Volkov RA, Hemleben V. 2005. Low-level taxonomy too intrageneric evolutionary trends inwards higher plants. In: Endress PK, Lüttge U, too Parthier B, eds. From Plant Taxonomy to Evolutionary Biology. Stuttgart: Wissenschaftl. Verlagsges. mbH, p. 129-145.
Grímsson F, Grimm GW, Zetter R, Denk T. 2016. Cretaceous too Paleogene Fagaceae from North America too Greenland: evidence for a Late Cretaceous separate betwixt Fagus and the remaining Fagaceae. Acta Palaeobotanica 56:247–305.
Heath TA, Huelsenbeck JP, Stadler T. 2014. The fossilized birth–death procedure for coherent calibration of divergence-time estimates. Proceedings of the National Academy of Sciences 111:E2957–E2966.
Hennig W. 1950. Grundzüge einer Theorie der phylogenetischen Systematik. Berlin: Dt. Zentralverlag.
Potts AJ, Hedderson TA, Grimm GW. 2014. Constructing phylogenies inwards the presence of intra-individual site polymorphisms (2ISPs) alongside a focus on the nuclear ribosomal cistron. Systematic Biology 63:1–16.
Renner SS, Grimm GW, Kapli P, Denk T. 2016. Species relationships too departure times inwards beeches: New insights from the inclusion of 53 immature too old fossils inwards a birth-death clock model. Philosophical Transactions of the Royal Society B DOI:10.1098/rstb.2015.0135.
Schliep K, Potts AJ, Morrison DA, Grimm GW. 2017. Intertwining phylogenetic trees too networks. Methods inwards Ecology too Evolution DOI:10.1111/2041-210X.12760.
Spencer M, Davidson EA, Barbrook AC, Howe CJ. 2004. Phylogenetics of artificial manuscripts. Journal of Theoretical Biology 227:503-511.
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