The beating heart of Jonathan Bree’s old band, The Brunettes, was the whimsical lilt of the band’s other member, Heather Mansfield. Her lightness was such an influence on that band’s sound, that even when they tried really hard, they could only go so dark. Without her brightening the mood, on his debut solo album The Primrose Path, it seems that Jonathan Bree is free to get depressing.
Provided to YouTube by Believe SAS The Primrose Path Jonathan Bree The Primrose Path ℗ Lil' Chief Records Released on: 2013-06-21 Author: RR Composer: RR A. Skip navigation Sign in. Jonathan Bree has dropped his first single 'The Primrose Path'. The song is set on K Rd in Auckland, NZ and is about some violent sociopath trying to act like an ok guy. The single 'Primrose Path' is from an upcoming album also titled 'The Primrose Path'.
Given that, it’s surprising that the distinguishing feature of The Primrose Path is that it’s an album without sharp edges or tight turns. Thematically, this is an album about control - it’s about emotions being kept in check, sounds that convey meaning with their subtlety, rather than their power. From the outside, controlling passion can look a lot like having none in the first place. If we were to go by lyrics alone, The Primrose Path might look like an ode to inaction. The themes explored have to do with frustrated emotions that have consigned themselves to only barely being felt. The track ‘Seven’ tells the story of an unrequited love that the singer has never moved on from - he’s with a new love, but fantasizes about the one that got away; he’s a tired man, trying to be happy with what he has. Sounds unbearably maudlin, right.
Well, it’s listenable because of everything else that goes on around the lyrics. The music is intricate, but perfectly weighted, demonstrating more of that control. The instrumentation is so beautifully, and meticulously complex that it’s often incongruous that it accompanies such inward-looking words. These strings and flutes are about something bigger than one man and his problems - they float above his words, making a mockery of them.
Not that this incongruity is a bad thing, it certainly has its charms. For instance, ‘Seven’, which is particularly maudlin is followed by a sweet instrumental of a palette cleanser, which is an example of what this album can be at its best. Though it’s not like the instrumentation is making up for poor lyrics either.
The lyrics are maudlin, yes, but there’s a diary-esque poetry to them that makes the writer a very likeable character. If there is a criticism to be made here, it’s that low-key nature (or control, which ever it is) means that the lyrics don’t pack much of a punch, even at their rawest. Though even that works from time to time. The album’s closer, 'Boxes', is about the heartbreak of the creative process not quite working out, when no one wants to hear what you have to say. The song doesn’t say much, because the singer has learnt his lesson, and ultimately that’s the most heartbreaking part. The title track is a refreshing surprise, as it completely flips the carefully laid out script.
The instrumentation on that one is sparse, barely there at times, but Bree’s voice gets a little bit of bite. Bree plays a character, and this song is that character’s dark side. The lyrics “I’ll be good to you on the primrose path, and we’ll forget I’m a sociopath” come out with a growl, like the control has slipped, despite the fact that they speak of control. It’s a fitting summation of the contradictions that make this album unique.
Since Darwin published the “Origin,” great progress has been made in our understanding of speciation mechanisms. The early investigations by Mayr and Dobzhansky linked Darwin's view of speciation by adaptive divergence to the evolution of reproductive isolation, and thus provided a framework for studying the origin of species. However, major controversies and questions remain, including: When is speciation nonecological? Under what conditions does geographic isolation constitute a reproductive isolating barrier?
And How do we estimate the “importance” of different isolating barriers? Here, we address these questions, providing historical background and offering some new perspectives. A topic of great recent interest is the role of ecology in speciation.
“Ecological speciation” is defined as the case in which divergent selection leads to reproductive isolation, with speciation under uniform selection, polyploid speciation, and speciation by genetic drift defined as “nonecological.” We review these proposed cases of nonecological speciation and conclude that speciation by uniform selection and polyploidy normally involve ecological processes. Furthermore, because selection can impart reproductive isolation both directly through traits under selection and indirectly through pleiotropy and linkage, it is much more effective in producing isolation than genetic drift. We thus argue that natural selection is a ubiquitous part of speciation, and given the many ways in which stochastic and deterministic factors may interact during divergence, we question whether the ecological speciation concept is useful. We also suggest that geographic isolation caused by adaptation to different habitats plays a major, and largely neglected, role in speciation. We thus provide a framework for incorporating geographic isolation into the biological species concept (BSC) by separating ecological from historical processes that govern species distributions, allowing for an estimate of geographic isolation based upon genetic differences between taxa.
Finally, we suggest that the individual and relative contributions of all potential barriers be estimated for species pairs that have recently achieved species status under the criteria of the BSC. Only in this way will it be possible to distinguish those barriers that have actually contributed to speciation from those that have accumulated after speciation is complete.
We conclude that ecological adaptation is the major driver of reproductive isolation, and that the term “biology of speciation,” as proposed by Mayr, remains an accurate and useful characterization of the diversity of speciation mechanisms. Since Darwin's publication of the Origin of Species in 1859, the study of speciation has always generated enthusiasm and passionate debate. Interest in the subject continues to grow, as evidenced by an exponential rise in citations of speciation studies over the last three decades.
This is perhaps not surprising, given the view espoused by Mayr, and probably held by many researchers, that the origin of species is “ the single most important event in evolution” (, p. Yet, our poor understanding and lack of agreement on seemingly fundamental aspects of the topic is surprising. Despite more than a century of research on the ecological and genetic mechanisms of speciation, major questions remain. Web of Science literature search for citations of the topic “speciation” for the years 1979–2008, refined to subject areas “evolutionary biology,”“ecology,” or “genetics and heredity.” For example, when is speciation nonecological?
It was recently suggested that distinguishing ecological from nonecological speciation will improve our understanding of speciation mechanisms (;; ). Is this a false dichotomy? How is it that we cannot even agree on the terminology of speciation, or when and how ecology is involved? Consider Mayr's solution to this problem: The majority of the factors that we have to discuss are environmental, and we might therefore speak of an “ecology of speciation.” However, since we have to include the internal factors (mutability), as well as factors that involve behavior patterns, such as crossability, sexual isolation, pair formation, and the like, it might be preferable to use the broader term, biology. (, Chapter IX—The Biology of Speciation, p.
Given the long‐held view that ecology and divergent selection are major factors in speciation (;;; ), one might ask, what does the proposed focus on ecological speciation offer that was lacking in previous treatments? Even among biologists who believe speciation is sometimes nonecological, there is broad agreement that adaptation plays a significant role in most cases ( ). Nevertheless, the mechanisms whereby genetic changes resulting from adaptation contribute to the evolution of reproductive isolation remain poorly understood.
Consider the many ways in which even a single adaptive mutation may affect multiple components of reproductive isolation. For example, adaptation to different habitats may lead to the restriction of gene flow and a gene contributing to this divergence may have pleiotropic effects on other traits, and these may cause more isolation. This leads to the question, how do the genetic and phenotypic changes required for speciation arise, and how do they cause complete reproductive isolation? The importance of different isolating barriers to speciation remains a topic of considerable debate ( ). How do we estimate total reproductive isolation and which barriers do we include? For example, there is substantial disagreement about how one should measure and interpret isolation that results from differences in geographic distribution.
Are genetically based differences in distribution legitimate isolating barriers, as suggested by, or does the difficulty in distinguishing historical factors from geographic adaptation require that studies of speciation be restricted to sympatric taxa, as suggested by? Can we study speciation in allopatric taxa, and if so, how?
Finally, although most researchers acknowledge that the holy grail of speciation studies is to identify the magnitude and order of appearance of those isolating barriers that have actually contributed to speciation, there is disagreement as to how this can be accomplished. In their landmark papers, introduced a method in which the isolation contributed by late‐acting barriers is “discounted” by that from earlier barriers and the sum of the contributions across stages gives the total isolation.
They applied this approach to the study of premating isolation and postzygotic incompatibilities in Drosophila, and several studies have since expanded their method to multiple isolating barriers (;;; ). However, others have criticized this method because one cannot assume independence of different isolating barriers (; ), and there is some doubt as to the validity of the sequential ordering of individual barriers when estimating their contributions to the total isolation (H. Hence, there is disagreement on how to test the cornerstone of speciation research, that is, which forms of reproductive isolation are most “important?” Here, we discuss the questions put forth above in light of historical perspective and current practice to develop a research framework for studying the “biology of speciation.” We begin with a brief history of the role of ecological factors in speciation, and then explore the three “nonecological” mechanisms proposed by and, and conclude that ecology is rarely if ever truly absent from speciation.
We then discuss the potentially pervasive effect of ecology and natural selection on speciation, emphasizing the potential for both direct and indirect selection to result in reproductive isolation. We further examine the interaction between adaptation and geography to emphasize the importance of habitat isolation, which has been grossly understudied.
Next, focusing on the chronology of isolating barriers, we expand upon the framework developed previously by for assessing the relative importance of different forms of isolation. We conclude by recommending that future speciation studies examine the contribution of all potential isolating barriers, whether they are caused by ecological or nonecological mechanisms, or arise in sympatry or allopatry—an approach first envisioned by Dobzhansky and Mayr, the principal architects of our field. Developed the theory of natural selection to explain how populations diverge morphologically and ecologically as they adapt to local environmental conditions. To Darwin, speciation was simply the end point of a chronological series of steps, beginning with variation among individuals within species to the production of adaptively differentiated varieties and eventually to new species, with extinctions occurring along the way.
Darwin's view that species originate by adaptive divergence is perhaps best illustrated in the section titled “The Probable Effects of the Action of Natural Selection through Divergence of Character and Extinction, on the Descendants of a Common Ancestor,” in chapter IV of the “Origin.” Here he illustrates how natural selection acts to differentiate varieties that ultimately evolve to become different species. He concludes, “The complex and little known laws governing the production of varieties are the same, as far as we can judge, with the laws which have governed the production of distinct species” (p. Darwin's views on the role of ecological divergence in the origin of species were articulated most clearly in his unpublished “Big Book,” where, as an example, he describes how selection on drought tolerance in a group of plants might contribute to adaptive divergence and speciation (Diagram I in ).
Although he did little to connect natural selection with reproductive isolation, it is clear that Darwin viewed ecological adaptation as the key to understanding the origin of species. Since Darwin, our understanding of speciation has been improved dramatically by the adoption of biological species concept (BSC), which defines species as interbreeding natural populations. The first author to propose a species definition based on interbreeding was, who not only defined species by reproductive isolation, but also addressed the relative importance of pre‐ versus postmating barriers.
He clearly viewed premating barriers as vital to the speciation process, saying, “It will be argued that the true interspecific barrier is not sterility but Asyngamy—the cessation of interbreeding—but that the first will inevitably follow, sooner or later, as the incidental consequence of the second” (, p. He continues by offering a list of these premating reproductive barriers including “asyngamy” as a consequence of allopatry, mechanical isolation, and preferential mating.
Dobzhansky provided the first complete list of possible isolating barriers between species (1937, p. 231–232), and included “ecological isolation” as an example of reproductive (genetically based) isolation, in which “Representatives of the populations occur in different habitats in the same general region.” Dobzhansky placed seasonal and temporal isolation in a separate category, although these clearly fall under the rubric of ecological isolation. In addition to ecological barriers that act prior to hybrid formation, Dobzhansky also acknowledged the role of ecology and natural selection in postzygotic isolation, “ the genotype of a species is an integrated system adapted to the ecological niche in which the species lives. Gene recombination in the offspring of species hybrids may lead to formation of discordant gene patterns. This decreases the reproductive potentials of both interbreeding species” (1951, p.
Judged ecological factors as the major drivers of speciation. In his classic paper “Ecological factors in speciation,” concluded that geographic isolation leads to the formation of segregated populations that experience different ecological conditions, leading to evolutionary divergence. In Animal Species and Evolution, (1963, p. 556) devoted an entire chapter to the role of ecology in speciation, and began the second paragraph as follows: “An exhaustive treatment of the indicated subject matter would require an entire book, for there is hardly an ecological factor that does not affect speciation directly or indirectly, actually or potentially.” Many other evolutionary biologists have also supported the notion that ecological divergence of populations is typically required for speciation.
234n) concluded “ speciation, the basic process of radiation, is normally adaptive,” and provided numerous examples in which ecological factors are the primary isolating barriers between species. Our brief summary illustrates that natural selection and ecological factors have been at the center of discussions of speciation mechanisms since the inception of the field. In, we compile more recent examples in which ecology is either demonstrated or strongly implicated in the evolution of reproductive isolation. These include studies of phenotypes and behavior, such as demonstration of extrinsic postzygotic isolation in sticklebacks, study of ecogeographic and pollinator isolation in Mimulus, and investigation of sexual isolation via divergent selection in Drosophila.
Molecular genetic approaches also provide evidence of the role of natural selection in generating reproductive isolation, such as demonstration of direct selection on a protein involved in gametic isolation between sea urchins, and studies in Drosophila on loci involved in Dobzhansky–Muller incompatibilities (; ). Reproductive barrier System Role of ecology References Habitat isolation Lucania (killifish) L. Goodie and L.
Parva display reduced survival to adulthood when reared at nonnative salinity levels. Natural distributions along salinity gradients generally correspond to fitness differentiation.
Drosophila (fruit fly) D. Santomea and D. Yakuba inhabit distinct habitats based on ecological conditions associated with elevation. Both species exhibit reduced survival to adulthood and fertility when reared at nonnative temperatures, and each species chooses its native temperature range when placed on a temperature cline. Mimulus (monkeyflower) M.
Lewisii and M. Cardinalis show considerable allopatric separation based primarily on differences in altitude inhabited. Reciprocal transplants demonstrate that each species is most fit in its native range.; Temporal isolation Inurois (geometrid moth) Populations of I. Punctigera in colder climates show divergence for early or late flight periods conferring temporal reproductive isolation. Mimulus Inland and coastal forms of M.
Guttatus experience selection for different growth and flowering times resulting in flowering phenology with little overlap. Sexual and pollinator isolation Drosophila Divergent artificial selection in laboratory populations of D.
Serrata results in assortative mating. Gasterosteus (stickleback fish) Anadromous and freshwater G. Aculeatus experience divergent selection for body size and assortative mating is based on this trait. Mimulus In sympatry, M. Cardinalis and M.
Lewisii experience almost complete reproductive isolation due to pollinator preference for floral traits. Gametic isolation Echinometra (sea urchin) Lineage specific positive selection on bindin, a gamete recognition protein, was detected in E. Lucunter, which experience a strong block to fertilization by sperm of its Neotropical congeners. Mimulus Divergent pollinator‐selected style lengths in Mimulus cardinalis and M.
Lewisii lead to differentiated pollen tube lengths, reducing the amount of expected hybridization in mixed pollinations. Intrinsic postzygotic isolation Drosophila Adaptive divergence in nuclear pore proteins causes lethality in hybrids of D. Melanogaster and D. Drosophila Hybrid incompatibility and sterility between D.
Melanogaster and sibling species D. Mauritiana, and D.
Sechellia involves the Hmr gene that exhibits signature of positive selection.; Mimulus Hybrid inviability between M. Guttatus populations on and off copper mine tailings is linked to two genes for copper tolerance. Extrinsic postzygotic isolation Gasterosteus Divergent natural selection causes low fitness in G.
Aculeatus benthic–limnetic hybrids, despite the absence of intrinsic postzygotic isolation.; Sylvia (warbler) Hybrids between divergently migrating populations of Sylvia atricapilla exhibit unfit intermediate migration patterns. Heliconius (butterfly) Mimicry in H. Melpomene is disrupted in hybrids, causing increased predation on hybrids and reduced mating success.; In the past decade, a number of papers have suggested that it is useful to distinguish ecological from nonecological mechanisms to elucidate the role of natural selection in speciation, for example,. What sets these efforts apart from previous discussion is the proposal of the term, “ecological speciation,” which is defined variously as when divergent selection on traits between populations or subpopulations in contrasting environments leads directly or indirectly to the evolution of reproductive isolation (, p.
372); the process by which barriers to gene flow evolve between populations as a result of ecologically‐based divergent selection (, p. 336); A speciation process in which divergent natural selection drives the evolution of reproductive incompatibility (i.e., isolation) between taxa (, p.
The evolution of reproductive isolation between populations or subsets of a single population by adaptation to different environments or ecological niches (, p. Suggested that “ until recently, neither was there evidence to support ecological speciation, nor had tests been devised to distinguish ecological speciation from other mechanisms that might cause speciation in the wild, such as genetic drift” (Box 1 in ). 336) suggest that the renewed focus on ecological speciation has developed alongside recent efforts for “ a reclassification of speciation models from a scheme of geography (i.e., sympatric vs. Allopatric), to one that focuses on mechanisms for the evolution of reproductive isolation ” The ecological speciation perspective has rekindled interest in the critical role of ecological factors in speciation, so in this sense it has been extremely valuable. However, natural selection and ecological factors have been at the center of discussions about speciation mechanisms for many decades.
Consider the classic studies of Dobzhansky and colleagues on mechanisms of reproductive isolation in Drosophila. Concluded that gene flow between Drosophila pseudoobscura and D. Persimilis was prevented by at least seven different isolating mechanisms, including such ecological factors as differences in habitat, preferred foods, and activity periods.
Conducted landmark studies on two closely related species of monkeyflowers, Mimulus cardinalis and M. Lewisii, and through extensive reciprocal transplant experiments, crossing studies, and physiological observations demonstrated unmistakably that ecology and natural selection were the major factors contributing to speciation. In birds, the extraordinary radiation of Hawaiian honeycreepers from a single common ancestor, with species differentially adapted for feeding on nectar, fruits, seeds, or insects ( ), must surely represent an irrefutable example of divergent natural selection as a major cause of reproductive isolation. Moreover, the suggestion that the ecological speciation perspective affords investigators a new opportunity to study the mechanisms of reproductive isolation fails to recognize that and had already established a complete inventory of reproductive isolating barriers more than a half century ago.
Given this historical appreciation of ecological factors in speciation, the new perspective serves to direct attention to how the presence and strength of divergent selection affects reproductive isolation, but provides little new insight into how ecological versus non‐ecological mechanisms are involved. We begin by examining the three proposed forms of nonecological speciation: speciation under uniform selection, polyploid speciation, and speciation by genetic drift ( in ). We show that ecology is involved in speciation by both uniform selection and polyploidy, and that genetic drift is unlikely to cause speciation unilaterally. Within the “ecological speciation” framework, speciation must sometimes be ecological and at other times, it must not be. Given our review of these cases, we ask the question: When is speciation nonecological?