1
|
Beausoleil MO, Carrión PL, Podos J, Camacho C, Rabadán-González J, Richard R, Lalla K, Raeymaekers JAM, Knutie SA, De León LF, Chaves JA, Clayton DH, Koop JAH, Sharpe DMT, Gotanda KM, Huber SK, Barrett RDH, Hendry AP. The fitness landscape of a community of Darwin's finches. Evolution 2023; 77:2533-2546. [PMID: 37671423 DOI: 10.1093/evolut/qpad160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 06/22/2023] [Accepted: 08/31/2023] [Indexed: 09/07/2023]
Abstract
Divergent natural selection should lead to adaptive radiation-that is, the rapid evolution of phenotypic and ecological diversity originating from a single clade. The drivers of adaptive radiation have often been conceptualized through the concept of "adaptive landscapes," yet formal empirical estimates of adaptive landscapes for natural adaptive radiations have proven elusive. Here, we use a 17-year dataset of Darwin's ground finches (Geospiza spp.) at an intensively studied site on Santa Cruz (Galápagos) to estimate individual apparent lifespan in relation to beak traits. We use these estimates to model a multi-species fitness landscape, which we also convert to a formal adaptive landscape. We then assess the correspondence between estimated fitness peaks and observed phenotypes for each of five phenotypic modes (G. fuliginosa, G. fortis [small and large morphotypes], G. magnirostris, and G. scandens). The fitness and adaptive landscapes show 5 and 4 peaks, respectively, and, as expected, the adaptive landscape was smoother than the fitness landscape. Each of the five phenotypic modes appeared reasonably close to the corresponding fitness peak, yet interesting deviations were also documented and examined. By estimating adaptive landscapes in an ongoing adaptive radiation, our study demonstrates their utility as a quantitative tool for exploring and predicting adaptive radiation.
Collapse
Affiliation(s)
| | - Paola Lorena Carrión
- Redpath Museum and Department of Biology, McGill University, Montréal, Québec, Canada
| | - Jeffrey Podos
- Department of Biology, University of Massachusetts Amherst, Amherst, MA, United States
| | - Carlos Camacho
- Department of Ecology and Evolution, Estación Biológica de Doñana-CSIC, Sevilla, Spain
| | | | - Roxanne Richard
- Redpath Museum and Department of Biology, McGill University, Montréal, Québec, Canada
| | - Kristen Lalla
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, Québec, Canada
| | | | - Sarah A Knutie
- Department of Ecology and Evolutionary Biology, Institute for Systems Genomics, University of Connecticut, Storrs, CT, United States
| | - Luis F De León
- Department of Biology, University of Massachusetts Boston, Boston, MA, United States
| | - Jaime A Chaves
- Department of Biology, San Francisco State University, San Francisco, CA, United States
- Colegio de Ciencias Biológicas y Ambientales, Universidad San Francisco de Quito, Quito, Ecuador
| | - Dale H Clayton
- School of Biological Sciences, University of Utah, Salt Lake City, UT, United States
| | - Jennifer A H Koop
- Department of Biological Sciences, Northern Illinois University, DeKalb, IL, United States
| | - Diana M T Sharpe
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, United States
| | - Kiyoko M Gotanda
- Redpath Museum and Department of Biology, McGill University, Montréal, Québec, Canada
- Department of Biological Sciences, Brock University, St. Catharines, Ontario, Canada
- Department of Zoology, University of Cambridge, United Kingdom
- Département de biologie, Université de Sherbrooke, Québec, Canada
| | - Sarah K Huber
- Virginia Institute of Marine Science, William and Mary, Gloucester Point, VA, United States
| | - Rowan D H Barrett
- Redpath Museum and Department of Biology, McGill University, Montréal, Québec, Canada
| | - Andrew P Hendry
- Redpath Museum and Department of Biology, McGill University, Montréal, Québec, Canada
| |
Collapse
|
2
|
Mosleh S, Choi GPT, Musser GM, James HF, Abzhanov A, Mahadevan L. Beak morphometry and morphogenesis across avian radiations. Proc Biol Sci 2023; 290:20230420. [PMID: 37752837 PMCID: PMC10523063 DOI: 10.1098/rspb.2023.0420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 08/18/2023] [Indexed: 09/28/2023] Open
Abstract
Adaptive avian radiations associated with the diversification of bird beaks into a multitude of forms enabling different functions are exemplified by Darwin's finches and Hawaiian honeycreepers. To elucidate the nature of these radiations, we quantified beak shape and skull shape using a variety of geometric measures that allowed us to collapse the variability of beak shape into a minimal set of geometric parameters. Furthermore, we find that just two measures of beak shape-the ratio of the width to length and the normalized sharpening rate (increase in the transverse beak curvature near the tip relative to that at the base of the beak)-are strongly correlated with diet. Finally, by considering how transverse sections to the beak centreline evolve with distance from the tip, we show that a simple geometry-driven growth law termed 'modified mean curvature flow' captures the beak shapes of Darwin's finches and Hawaiian honeycreepers. A surprising consequence of the simple growth law is that beak shapes that are not allowed based on the developmental programme of the beak are also not observed in nature, suggesting a link between evolutionary morphology and development in terms of growth-driven developmental constraints.
Collapse
Affiliation(s)
- Salem Mosleh
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - Gary P. T. Choi
- Department of Mathematics, The Chinese University of Hong Kong, Hong Kong, Hong Kong
| | - Grace M. Musser
- Department of Integrative Biology, University of Texas at Austin, Austin, TX 78712, USA
- Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560, USA
| | - Helen F. James
- Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560, USA
| | - Arhat Abzhanov
- Department of Life Sciences, Imperial College London, Ascot SL5 7PY, UK
- Natural History Museum, Cromwell Road, London SW7 5BD, UK
| | - L. Mahadevan
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
- Department of Physics, Harvard University, Cambridge, MA 02138, USA
| |
Collapse
|
3
|
Al-Mosleh S, Choi GPT, Abzhanov A, Mahadevan L. Geometry and dynamics link form, function, and evolution of finch beaks. Proc Natl Acad Sci U S A 2021; 118:e2105957118. [PMID: 34750258 DOI: 10.1073/pnas.2105957118] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/11/2021] [Indexed: 11/18/2022] Open
Abstract
Darwin's finches are a classic example of adaptive radiation, exemplified by their adaptive and functional beak morphologies. To quantify their form, we carry out a morphometric analysis of the three-dimensional beak shapes of all of Darwin's finches and find that they can be fit by a transverse parabolic shape with a curvature that increases linearly from the base toward the tip of the beak. The morphological variation of beak orientation, aspect ratios, and curvatures allows us to quantify beak function in terms of the elementary theory of machines, consistent with the dietary variations across finches. Finally, to explain the origin of the evolutionary morphometry and the developmental morphogenesis of the finch beak, we propose an experimentally motivated growth law at the cellular level that simplifies to a variant of curvature-driven flow at the tissue level and captures the range of observed beak shapes in terms of a simple morphospace. Altogether, our study illuminates how a minimal combination of geometry and dynamics allows for functional form to develop and evolve.
Collapse
|
4
|
Abstract
Many species of plants, animals, and microorganisms exchange genes well after the point of evolutionary divergence at which taxonomists recognize them as species. Genomes contain signatures of past gene exchange and, in some cases, they reveal a legacy of lineages that no longer exist. But genomic data are not available for many organisms, and particularly problematic for reconstructing and interpreting evolutionary history are communities that have been depleted by extinctions. For these, morphology may substitute for genes, as exemplified by the history of Darwin's finches on the Galápagos islands of Floreana and San Cristóbal. Darwin and companions collected seven specimens of a uniquely large form of Geospiza magnirostris in 1835. The populations became extinct in the next few decades, partly due to destruction of Opuntia cactus by introduced goats, whereas Geospiza fortis has persisted to the present. We used measurements of large samples of G. fortis collected for museums in the period 1891 to 1906 to test for unusually large variances and skewed distributions of beak and body size resulting from introgression. We found strong evidence of hybridization on Floreana but not on San Cristóbal. The skew is in the direction of the absent G. magnirostris We estimate introgression influenced 6% of the frequency distribution that was eroded by selection after G. magnirostris became extinct on these islands. The genetic residuum of an extinct species in an extant one has implications for its future evolution, as well as for a conservation program of reintroductions in extinction-depleted communities.
Collapse
|
5
|
Heyer E, Cimadom A, Wappl C, Tebbich S. Parental care in the Small Tree Finch Camarhynchus parvulus in relation to parasitism and environmental factors. Ibis (Lond 1859) 2021; 163:137-149. [PMID: 33362293 PMCID: PMC7754105 DOI: 10.1111/ibi.12845] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 04/28/2020] [Indexed: 05/30/2023]
Abstract
The parental food compensation hypothesis suggests that parents may compensate for the negative effects of parasites on chicks by increased food provisioning. However, this ability differs widely among host species and may also depend on ecological factors such as adverse weather conditions and habitat quality. Although weed management can improve habitat quality, management measures can bring about a temporary decrease in food availability and thus may reduce parents' ability to provide their nestlings with enough energy. In our study we investigated the interaction of parasitism and weed management, and the influence of climate on feeding rates in a Darwin's tree finch species, which is negatively impacted by two invasive species. The larvae of the invasive parasitic fly Philornis downsi ingest the blood and body tissues of tree finch nestlings, and the invasive Blackberry Rubus niveus affects one of the main habitats of Darwin's tree finches. We compared parental food provisioning of the Small Tree Finch Camarhynchus parvulus in parasitized and parasite-free nests in three different areas, which differed in invasive weed management (no management, short-term and long-term management). In a parasite reduction experiment, we investigated whether the Small Tree Finch increases food provisioning rates to nestlings when parasitized and whether this ability depends on weed management conditions and precipitation. Our results provide no evidence that Small Tree Finches can compensate with additional food provisioning when parasitized with P. downsi. However, we found an increase in male effort in the short-term management area, which might indicate that males compensate for lower food quality with increased provisioning effort. Furthermore, parental food provisioning was lower during rainfall, which provides an explanation for the negative influence of rain on breeding success found in earlier studies. Like other Darwin's finches, the Small Tree Finch seems to lack the ability to compensate for the negative effects of P. downsi parasitism, which is one explanation for why this invasive parasite has such a devastating effect on this host species.
Collapse
Affiliation(s)
- Eileen Heyer
- Department of Behavioural BiologyUniversity of ViennaAlthanstraße 141090ViennaAustria
| | - Arno Cimadom
- Department of Behavioural BiologyUniversity of ViennaAlthanstraße 141090ViennaAustria
| | - Christian Wappl
- Department of Behavioural BiologyUniversity of ViennaAlthanstraße 141090ViennaAustria
| | - Sabine Tebbich
- Department of Behavioural BiologyUniversity of ViennaAlthanstraße 141090ViennaAustria
| |
Collapse
|
6
|
Cimadom A, Tebbich S. Timing of infestation influences virulence and parasite success in a dynamic multi-host-parasite interaction between the invasive parasite, Philornis downsi, and Darwin's finches. Oecologia 2021; 195:249-59. [PMID: 33258992 DOI: 10.1007/s00442-020-04807-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Accepted: 11/16/2020] [Indexed: 12/30/2022]
Abstract
Recently commenced host–parasite interactions provide an excellent opportunity to study co-evolutionary processes. Multi-host systems are especially informative because variation in virulence between hosts and temporal changes provides insight into evolutionary dynamics. However, empirical data under natural conditions are scarce. In the present study, we investigated the interaction between Darwin’s finches and the invasive fly Philornis downsi whose larvae feed on the blood of nestlings. Recently, however, the fly has changed its behavior and now also attacks incubating females. Two sympatric hosts are affected differently by the parasite and parasite load has changed over time. Our study observed a reversal of trends described two decades ago: while, currently, small tree finches (Camarhynchus parvulus) experience significantly higher parasite load than warbler finches (Certhidea olivacea), this was the opposite two decades ago. Currently, fledging success is higher in warbler finches compared to small tree finches. Our data indicate that not only intensity but also timing of infestation influences hosts’ reproductive success and parasite fitness. During incubation, prevalence was higher in warbler finches, but once chicks had hatched, prevalence was 100% in both species and parasite load was higher in small tree finches. Furthermore, our results suggest faster development and higher reproductive success of P. downsi in small tree finch nests. A change in host preference driven by larvae competition could have led to the reversal in parasite load.
Collapse
|
7
|
Abstract
Adaptive radiations are prominent components of the world's biodiversity. They comprise many species derived from one or a small number of ancestral species in a geologically short time that have diversified into a variety of ecological niches. Several authors have proposed that introgressive hybridization has been important in the generation of new morphologies and even new species, but how that happens throughout evolutionary history is not known. Interspecific gene exchange is expected to have greatest impact on variation if it occurs after species have diverged genetically and phenotypically but before genetic incompatibilities arise. We use a dated phylogeny to infer that populations of Darwin's finches in the Galápagos became more variable in morphological traits through time, consistent with the hybridization hypothesis, and then declined in variation after reaching a peak. Some species vary substantially more than others. Phylogenetic inferences of hybridization are supported by field observations of contemporary hybridization. Morphological effects of hybridization have been investigated on the small island of Daphne Major by documenting changes in hybridizing populations of Geospiza fortis and Geospiza scandens over a 30-y period. G. scandens showed more evidence of admixture than G. fortis Beaks of G. scandens became progressively blunter, and while variation in length increased, variation in depth decreased. These changes imply independent effects of introgression on 2, genetically correlated, beak dimensions. Our study shows how introgressive hybridization can alter ecologically important traits, increase morphological variation as a radiation proceeds, and enhance the potential for future evolution in changing environments.
Collapse
|
8
|
Michel AJ, Ward LM, Goffredi SK, Dawson KS, Baldassarre DT, Brenner A, Gotanda KM, McCormack JE, Mullin SW, O'Neill A, Tender GS, Uy JAC, Yu K, Orphan VJ, Chaves JA. The gut of the finch: uniqueness of the gut microbiome of the Galápagos vampire finch. Microbiome 2018; 6:167. [PMID: 30231937 PMCID: PMC6146768 DOI: 10.1186/s40168-018-0555-8] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 09/05/2018] [Indexed: 05/13/2023]
Abstract
BACKGROUND Darwin's finches are a clade of 19 species of passerine birds native to the Galápagos Islands, whose biogeography, specialized beak morphologies, and dietary choices-ranging from seeds to blood-make them a classic example of adaptive radiation. While these iconic birds have been intensely studied, the composition of their gut microbiome and the factors influencing it, including host species, diet, and biogeography, has not yet been explored. RESULTS We characterized the microbial community associated with 12 species of Darwin's finches using high-throughput 16S rRNA sequencing of fecal samples from 114 individuals across nine islands, including the unusual blood-feeding vampire finch (Geospiza septentrionalis) from Darwin and Wolf Islands. The phylum-level core gut microbiome for Darwin's finches included the Firmicutes, Gammaproteobacteria, and Actinobacteria, with members of the Bacteroidetes at conspicuously low abundance. The gut microbiome was surprisingly well conserved across the diversity of finch species, with one exception-the vampire finch-which harbored bacteria that were either absent or extremely rare in other finches, including Fusobacterium, Cetobacterium, Ureaplasma, Mucispirillum, Campylobacter, and various members of the Clostridia-bacteria known from the guts of carnivorous birds and reptiles. Complementary stable isotope analysis of feathers revealed exceptionally high δ15N isotope values in the vampire finch, resembling top marine predators. The Galápagos archipelago is also known for extreme wet and dry seasons, and we observed a significant seasonal shift in the gut microbial community of five additional finch species sampled during both seasons. CONCLUSIONS This study demonstrates the overall conservatism of the finch gut microbiome over short (< 1 Ma) divergence timescales, except in the most extreme case of dietary specialization, and elevates the evolutionary importance of seasonal shifts in driving not only species adaptation, but also gut microbiome composition.
Collapse
Affiliation(s)
- Alice J Michel
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Lewis M Ward
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Shana K Goffredi
- Department of Biology, Occidental College, Los Angeles, CA, 90041, USA
| | - Katherine S Dawson
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
- School of Environmental and Biological Sciences, Rutgers University, New Brunswick, NJ, 08901, USA
| | - Daniel T Baldassarre
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, 08544, USA
| | - Alec Brenner
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Kiyoko M Gotanda
- Department of Zoology, University of Cambridge, Cambridge, CB2 3EJ, England
| | - John E McCormack
- Department of Biology, Occidental College, Los Angeles, CA, 90041, USA
| | - Sean W Mullin
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Ariel O'Neill
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Gabrielle S Tender
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
| | - J Albert C Uy
- Department of Biology, University of Miami, Coral Gables, FL, 33146, USA
| | - Kristie Yu
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Victoria J Orphan
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA.
| | - Jaime A Chaves
- Colegio de Ciencias Biológicas y Ambientales, Universidad San Francisco de Quito, Diego de Robles y Pampite, Quito, Ecuador.
- Galápagos Science Center, Puerto Baquerizo Moreno, Galápagos, Ecuador.
| |
Collapse
|
9
|
Clark TD, Kleindorfer S, Dudaniec RY. Baseline and stress-induced blood properties of male and female Darwin's small ground finch (Geospiza fuliginosa) of the Galapagos Islands. Gen Comp Endocrinol 2018; 259:199-206. [PMID: 29197554 DOI: 10.1016/j.ygcen.2017.11.026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 11/01/2017] [Accepted: 11/28/2017] [Indexed: 10/18/2022]
Abstract
Birds are renowned for exhibiting marked sex-specific differences in activity levels and reproductive investment during the breeding season, potentially impacting circulating blood parameters associated with stress and energetics. Males of many passerines often do not incubate, but they experience direct exposure to intruder threat and exhibit aggressive behaviour during the nesting phase in order to defend territories against competing males and predators. Nesting females often have long bouts of inactivity during incubation, but they must remain vigilant of the risks posed by predators and conspecific intruders approaching the nest. Here, we use 33 free-living male (n = 16) and female (n = 17) Darwin's small ground finches (Geospiza fuliginosa) on Floreana Island (Galapagos Archipelago) to better understand how sex-specific roles during the reproductive period impact baseline and stress-induced levels of plasma corticosterone (CORT), blood glucose and haematocrit. Specifically, we hypothesise that males are characterised by higher baseline values given their direct and relatively frequent exposure to intruder threat, but that a standardised stress event (capture and holding) overrides any sex-specific differences. In contrast with expectations, baseline levels of all blood parameters were similar between sexes (13.4 ± 1.9 ng ml-1 for CORT, 13.7 ± 0.4 mmol l-1 for glucose, 58.3 ± 0.8% for haematocrit). Interestingly, females with higher body condition had lower baseline haematocrit. All blood parameters changed with time since capture (range 1.2-41.3 min) in both sexes, whereby CORT increased linearly, haematocrit decreased linearly, and glucose increased to a peak at ∼20 min post-capture and declined to baseline levels thereafter. Our results do not support the hypothesis that sex-specific roles during the reproductive period translate to differences in blood parameters associated with stress and energetics, but we found some evidence that blood oxygen transport capacity may decline as finches increase in body condition.
Collapse
Affiliation(s)
- Timothy D Clark
- Deakin University, School of Life and Environmental Sciences, Geelong 3216, Australia
| | - Sonia Kleindorfer
- College of Science and Engineering, Flinders University, Adelaide 5001, Australia.
| | - Rachael Y Dudaniec
- Department of Biological Sciences, Macquarie University, Sydney 2109, Australia
| |
Collapse
|
10
|
Abstract
Adaptation by means of natural selection depends on the ability of populations to maintain variation in heritable traits. According to the Modern Synthesis this variation is sustained by mutations and genetic drift. Epigenetics, evodevo, niche construction and cultural factors have more recently been shown to contribute to heritable variation, however, leading an increasing number of biologists to call for an extended view of speciation and evolution. An additional common feature across the animal kingdom is learning, defined as the ability to change behavior according to novel experiences or skills. Learning constitutes an additional source for phenotypic variation, and change in behavior may induce long lasting shifts in fitness, and hence favor evolutionary novelties. Based on published studies, I demonstrate how learning about food, mate choice and habitats has contributed substantially to speciation in the canonical story of Darwin's finches on the Galapagos Islands. Learning cannot be reduced to genetics, because it demands decisions, which requires a subject. Evolutionary novelties may hence emerge both from shifts in allelic frequencies and from shifts in learned, subject driven behavior. The existence of two principally different sources of variation also prevents the Modern Synthesis from self-referring explanations.
Collapse
Affiliation(s)
- Markus Lindholm
- />Norwegian Institute for Water Research (NIVA), Gaustadalléen 21, 0349 Oslo, Norway
- />Rudolf Steiner University College, Dahls gate 30, 0260 Oslo, Norway
| |
Collapse
|