Are adaptive zones important in macroevolution?
Lead Research Organisation:
Natural History Museum
Department Name: Life Sciences
Abstract
Many researchers think that most of life's staggering diversity may have arisen by a process known as adaptive radiation. In adaptive radiation, an ancestral population gets an evolutionary windfall - for any of several reasons, it finds itself surrounded by a set of empty niches, and so diversifies both taxonomically and ecologically, resulting in a range of species adapted to different niches. This model assumes that niches in nature really are ordered hierarchically into groups known as adaptive zones; niches in the same adaptive zone are sufficiently similar that, given time, a species adapted to any one of them could colonise and adapt to the others.
These adaptive zones are among the longest-standing metaphors in evolutionary biology; since it was proposed in 1944, the idea has shaped thinking about evolutionary 'arms races', where competing species are locked in an ongoing struggle of thrust and counterthrust, as well as about adaptive radiation. If the idea is right, it makes predictions about how ecological communities and groups of closely-related species will evolve. Surprisingly, however, we don't really know how important adaptive zones have been in shaping the pattern of evolution. Progress has been difficult because most groups that everyone agrees are adaptive radiations don't have a good fossil record, because many of these groups can only be studied in one place (frustrating scientists' desire to replicate their findings), and because most places on Earth have changed so much over geological time that climate change is a possible explanation for whatever pattern is seen.
We propose to investigate the importance of adaptive zones in shaping large-scale evolutionary patterns by focusing on the group with probably the best fossil record of all - a group of single-celled oceanic microbes called planktonic foraminifera - in two of the world's oldest and most stable ecosystems - the North Pacific and North Atlantic subtropical oceanic gyres. Within each gyre, we will take fossil samples every million years back to 23 million years ago; this is made possible by the many expeditions that have drilled the sea bed and brought back layer upon layer of fossils that had accumulated there. We will estimate how abundant each species was at each time slice, and take detailed measurements of their sizes and shapes.
Our data will provide an unprecedentedly rich picture of how the group has evolved in this unusually stable system, so we can test whether predictions from adaptive zones are correct. For example, if each adaptive zone provides a different way of being an evolutionary success, then we should see species' size and shape evolve towards those same successful morphologies time and again; and, if species within an adaptive zone compete, then when one became more abundant through time its competitors should have become rarer. If morphology and abundance produce a consistent picture of what the MPF adaptive zones have been, then they will also provide an objective way of delimiting adaptive zones - something that we currently lack.
Our data will also help to develop a better understanding of how size and shape evolve along the branches of the evolutionary 'family tree' that links all species, providing answer to longstanding questions: When does morphology change quickly and when slowly? Do species within an adaptive zone affect each other's evolution - and indeed whether they even survive?
Most adaptive radiations don't allow researchers to ask such questions (or, even if they do, they force us to make many untestable assumptions). However, though our results couldn't be obtained for those other systems, our findings will be of interest to the researchers working on them: we may identify important processes that their analyses currently omit. As well as telling us about planktonic foraminifera, this project will help us understand how much of life's diversity may have arisen.
These adaptive zones are among the longest-standing metaphors in evolutionary biology; since it was proposed in 1944, the idea has shaped thinking about evolutionary 'arms races', where competing species are locked in an ongoing struggle of thrust and counterthrust, as well as about adaptive radiation. If the idea is right, it makes predictions about how ecological communities and groups of closely-related species will evolve. Surprisingly, however, we don't really know how important adaptive zones have been in shaping the pattern of evolution. Progress has been difficult because most groups that everyone agrees are adaptive radiations don't have a good fossil record, because many of these groups can only be studied in one place (frustrating scientists' desire to replicate their findings), and because most places on Earth have changed so much over geological time that climate change is a possible explanation for whatever pattern is seen.
We propose to investigate the importance of adaptive zones in shaping large-scale evolutionary patterns by focusing on the group with probably the best fossil record of all - a group of single-celled oceanic microbes called planktonic foraminifera - in two of the world's oldest and most stable ecosystems - the North Pacific and North Atlantic subtropical oceanic gyres. Within each gyre, we will take fossil samples every million years back to 23 million years ago; this is made possible by the many expeditions that have drilled the sea bed and brought back layer upon layer of fossils that had accumulated there. We will estimate how abundant each species was at each time slice, and take detailed measurements of their sizes and shapes.
Our data will provide an unprecedentedly rich picture of how the group has evolved in this unusually stable system, so we can test whether predictions from adaptive zones are correct. For example, if each adaptive zone provides a different way of being an evolutionary success, then we should see species' size and shape evolve towards those same successful morphologies time and again; and, if species within an adaptive zone compete, then when one became more abundant through time its competitors should have become rarer. If morphology and abundance produce a consistent picture of what the MPF adaptive zones have been, then they will also provide an objective way of delimiting adaptive zones - something that we currently lack.
Our data will also help to develop a better understanding of how size and shape evolve along the branches of the evolutionary 'family tree' that links all species, providing answer to longstanding questions: When does morphology change quickly and when slowly? Do species within an adaptive zone affect each other's evolution - and indeed whether they even survive?
Most adaptive radiations don't allow researchers to ask such questions (or, even if they do, they force us to make many untestable assumptions). However, though our results couldn't be obtained for those other systems, our findings will be of interest to the researchers working on them: we may identify important processes that their analyses currently omit. As well as telling us about planktonic foraminifera, this project will help us understand how much of life's diversity may have arisen.
Planned Impact
Who will benefit from this research?
Commercial private sector: Potential long-term benefit in the field of petroleum geology
Public sector: Potential immediate and long-term benefit to museums and galleries
Society: Potential immediate and long-term benefit (albeit minor) to broader society
How will they benefit?
Petroleum geology: The specimen-level morphometric data for each species every ~1My through the Neogene could help to underpin a system for estimating the age of one or a few specimens from morphology, which could have commercial value. At present, dating of specimens is indirect, e.g., relying on identification of the list of species within a sample and cross-referencing with biostratigraphic charts. In principle, however, the morphology of one or a few specimens could be compared with the positions of all the group's species in ecomorphospace to enable a more direct estimate of sample age that may be more precise. Such a system is beyond the scope of this project, and it would probably require a much greater geographic spread of morphological data in order to be useful beyond the two gyres on which we are focusing. The system would be of value in helping to constrain the age of sediment samples that contain few specimens, which could be important in biostratigraphy and paleoenvironmental analysis.
Public sector: The animation of community evolution will provide an aesthetically beautiful depiction of the continuity of evolutionary history. This is important in its own right, given that many anti-evolutionists appeal to the incompleteness of the fossil record when rejecting evidence for evolution. It also provides a possible 'hook' for exhibitions explaining how microfossils like these foraminifera have been crucial for the development of our understanding of past climates, due to the geochemistry of their shells containing a record of the temperature of the water in which they lived. After displaying the animation at the Natural History Museum, we will make it available without charge for scientific and educational purposes.
Broader society: As indicated above, there is still widespread scepticism in society about the fact of evolutionary change, and even more scepticism about the reality of climate change. We will use the animation, images and specimens from this project to develop materials explaining evolution and paleoclimates, using them within the Natural History Museum's Science Live events and more widely to engage members of the public, including school children, in the ongoing scientific research.
Commercial private sector: Potential long-term benefit in the field of petroleum geology
Public sector: Potential immediate and long-term benefit to museums and galleries
Society: Potential immediate and long-term benefit (albeit minor) to broader society
How will they benefit?
Petroleum geology: The specimen-level morphometric data for each species every ~1My through the Neogene could help to underpin a system for estimating the age of one or a few specimens from morphology, which could have commercial value. At present, dating of specimens is indirect, e.g., relying on identification of the list of species within a sample and cross-referencing with biostratigraphic charts. In principle, however, the morphology of one or a few specimens could be compared with the positions of all the group's species in ecomorphospace to enable a more direct estimate of sample age that may be more precise. Such a system is beyond the scope of this project, and it would probably require a much greater geographic spread of morphological data in order to be useful beyond the two gyres on which we are focusing. The system would be of value in helping to constrain the age of sediment samples that contain few specimens, which could be important in biostratigraphy and paleoenvironmental analysis.
Public sector: The animation of community evolution will provide an aesthetically beautiful depiction of the continuity of evolutionary history. This is important in its own right, given that many anti-evolutionists appeal to the incompleteness of the fossil record when rejecting evidence for evolution. It also provides a possible 'hook' for exhibitions explaining how microfossils like these foraminifera have been crucial for the development of our understanding of past climates, due to the geochemistry of their shells containing a record of the temperature of the water in which they lived. After displaying the animation at the Natural History Museum, we will make it available without charge for scientific and educational purposes.
Broader society: As indicated above, there is still widespread scepticism in society about the fact of evolutionary change, and even more scepticism about the reality of climate change. We will use the animation, images and specimens from this project to develop materials explaining evolution and paleoclimates, using them within the Natural History Museum's Science Live events and more widely to engage members of the public, including school children, in the ongoing scientific research.
People |
ORCID iD |
Andy Purvis (Principal Investigator) | |
Paul Pearson (Co-Investigator) |
Publications
Al-Sabouni N
(2018)
Reproducibility of species recognition in modern planktonic foraminifera and its implications for analyses of community structure
in Journal of Micropalaeontology
Echeverría-Londoño S
(2020)
Dynamism and context-dependency in diversification of the megadiverse plant genus Solanum (Solanaceae)
in Journal of Systematics and Evolution
Fenton I
(2018)
Factors affecting consistency and accuracy in identifying modern macroperforate planktonic foraminifera
in Journal of Micropalaeontology
Fenton IS
(2016)
The impact of Cenozoic cooling on assemblage diversity in planktonic foraminifera.
in Philosophical transactions of the Royal Society of London. Series B, Biological sciences
Fenton IS
(2016)
Environmental Predictors of Diversity in Recent Planktonic Foraminifera as Recorded in Marine Sediments.
in PloS one
Hsiang A
(2019)
Endless Forams: >34,000 Modern Planktonic Foraminiferal Images for Taxonomic Training and Automated Species Recognition Using Convolutional Neural Networks
in Paleoceanography and Paleoclimatology
Sánchez A
(2022)
Landscape complexity and functional groups moderate the effect of diversified farming on biodiversity: A global meta-analysis
in Agriculture, Ecosystems & Environment
Description | Spatial patterns of species richness in planktonic foraminifera are set by a range of environmental variables, among which sea surface temperature is most important. However, the relationship between temperature and diversity has changed over time, indicating that the 'rules' by which diversity is structured are not constant. Some key aspects of today's 'rules' were, however, already in place by 34 million years ago. A paper presenting these results was published in 2016 in Phil Trans R Soc B. A recurring criticism of analytical research like this project is that the species-level identification of specimens - fundamental to the data we analyse - is not very repeatable, with even experienced experts often disagreeing. We have tested this criticism, using a full repeatability analysis to show that agreement is very much higher than has previously been suggested. We have also assessed the consequences of imperfect identification on assemblage-level measures of diversity. This work led to two publications in 2018, and is improving our ongoing analyses of the importance of adaptive zones in macroevolution. We were also able to apply some of the phylogenetic comparative modelling approaches relevant to this project to a macroevolutionary analysis of the spatial, temporal and trait-specific patterns in macroevolutionary vital rates in the hyperdiverse plant genus, Solanum, in a paper published in 2020. Analyses towards the focal question of the proposal suggest that assemblages are indeed more morphologically stable over long periods of time in more stable gyre centres than more variable gyre edges, but that the short-term rates of evolution do not differ between the two environments. These results are consistent with some of the hypotheses developed in the proposal. Given the potential importance of the finding, we are not rushing to publication. |
Exploitation Route | The results of our diversity modelling highlight limitations of current models of paleoclimate. The repeatability results place analytical micropaleontology - at least of planktonic foraminifera - on a sounder footing. |
Sectors | Environment |
URL | http://rstb.royalsocietypublishing.org/content/371/1691/20150224 |
Description | DAAD Research Grants - Short-Term Grants, 2018 |
Amount | € 2,234 (EUR) |
Organisation | German Academic Exchange Service (DAAD) |
Sector | Academic/University |
Country | United States |
Start | 01/2018 |
End | 03/2018 |
Title | Scratchpad database on Neogene planktonic foraminifera taxonomy |
Description | Many workers on planktonic foraminifera have to use out-of-date information on their taxonomy and systematics. We have begun an open-access database that will provide a useful resource to such workers. Currently it is very sparsely population but we will continue to develop it throughout the 3-year project. |
Type Of Material | Improvements to research infrastructure |
Year Produced | 2015 |
Provided To Others? | Yes |
Impact | We have begun discussions with other researchers who have complementary systems in place for other microfossil groups and times. |
URL | http://planktonicforaminifera.myspecies.info/ |
Title | Definitive list of valid species names from the composite stratigraphic columns |
Description | An essential part of the project was to develop a definitive list of the valid species names from the composite stratigraphic columns, to ensure data integrity. The file has the consolidated list of species taken to be valid, across all the sites sampled in the project. Associated with each species are basic functional trait and other ecomorphological data, as well as first and last appearance times. |
Type Of Material | Database/Collection of data |
Year Produced | 2022 |
Provided To Others? | Yes |
Impact | Note yet. The data are only now being provided to the NERC EIDC. |
Title | Recent and Eocene planktonic foraminiferal diversity |
Description | Two datasets containing multiple diversity metrics of planktonic foraminifera. Recent data is derived by analysing data from MARGO; Eocene data is derived by analysing data from NEPTUNE and a range of sources found by literature searches. These data are related to Fenton et al (2016) Phil Trans |
Type Of Material | Database/Collection of data |
Year Produced | 2016 |
Provided To Others? | Yes |
Impact | The data have been re-used in other publications |
URL | https://doi.org/10.5519/0036305 |
Title | Recent foram diversity |
Description | These data, and the code that is also available through the same doi, were used to produce the analysis and results of the paper Fenton et al (2016) Environmental predictors of diversity in Recent planktonic foraminifera from marine sediment samples. |
Type Of Material | Database/Collection of data |
Year Produced | 2016 |
Provided To Others? | Yes |
Impact | The data have been reused in other publications subsequently |
URL | https://doi.org/10.5519/0008953 |
Title | Relative abundance data for planktonic foraminiferal assemblages |
Description | This data set is a series of spreadsheets recording the relative abundances of each planktonic foraminiferal species in each assemblage counted during the project |
Type Of Material | Database/Collection of data |
Year Produced | 2022 |
Provided To Others? | Yes |
Impact | None yet; the data are still in the process of being provided to the NERC EIDC |
Title | Sample locations in space and time |
Description | This file gives the latitude, longitude, depth and inferred age of each sample collected for the project |
Type Of Material | Database/Collection of data |
Year Produced | 2022 |
Provided To Others? | Yes |
Impact | None yet; the data are still in the process of being provided to the NERC EIDC |
Title | Specimen-level data from Al-Sabouni et al. 2018 |
Description | This data set and accompanying program code allow reproducibility of the results of Al Sabouni et al. 2018, who investigated reproducibility of species-level identifications and assessed its consequences for measures of assemblage diversity |
Type Of Material | Database/Collection of data |
Year Produced | 2018 |
Provided To Others? | Yes |
Impact | Assemblage-level measures of diversity differ in their sensitivity to identification errors |
URL | http://data.nhm.ac.uk/dataset/al-sabouni-et-al-reproducibility |
Title | Specimen-level database of planktonic foraminifera used in Fenton et al. 2018 |
Description | Fenton et al. (2018) formally tested repeatability of species-level identification of 100 planktonic foraminifera specimens from a Recent sample. The specimens used have been deposited within the NHM collection and the data are freely available online. |
Type Of Material | Database/Collection of data |
Year Produced | 2018 |
Provided To Others? | Yes |
Impact | The paper showed that people are able to identify many species reliably after only a few days of training, and that expert identification is much more reliable than had previously been suggested. |
URL | http://data.nhm.ac.uk/dataset/fenton-et-al-reproducibility |
Title | Specimen-level morphometric database |
Description | This database holds specimen-level morphometric data on planktonic foraminifera from different species, sites and times during the Neogene. |
Type Of Material | Database/Collection of data |
Year Produced | 2022 |
Provided To Others? | Yes |
Impact | None yet; the data are only currently in the process of being provided to the NERC EIDC |
Description | Function, form and foraminifera: a community perspective on macroevolution |
Organisation | University of Bremen |
Department | MARUM |
Country | Germany |
Sector | Academic/University |
PI Contribution | I have spent two months on a placement working in Bremen, to investigate how studying changes across space in the ocean today can inform our understanding of the past. Additionally I have been involved in writing up a study on the reproducibility of identifications in planktonic foraminifera |
Collaborator Contribution | They hosted me during my visit and we worked together on the project. |
Impact | Nothing as yet |
Start Year | 2018 |
Description | Forams 2018: International Symposium on Foraminifera |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Professional Practitioners |
Results and Impact | Organising committee for Forams 2018: International Symposium on Foraminifera - conference held every four years. |
Year(s) Of Engagement Activity | 2014 |
Description | Participation in an activity, workshop or similar - Planktonic foraminifera short course |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Postgraduate students |
Results and Impact | We ran a NERC ATSC short course at the Natural History Museum focussing on teaching the taxonomy and biostratigraphy of planktonic foraminifera to postgraduate students and early career researchers. I was involved as one of the course organisers / lecturers. The 2017 course also led directly to a paper, which will soon be submitted, showing that species-level identifications of planktonic foraminifera are more repeatable among different researchers than had previously been thought. |
Year(s) Of Engagement Activity | 2017,2018 |
Description | Planktonic foraminifera short course |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Postgraduate students |
Results and Impact | We ran a NERC ATSC short course at the Natural History Museum focussing on teaching the taxonomy and biostratigraphy of planktonic foraminifera to postgraduate students and early career researchers. I was involved as one of the course organisers / lecturers |
Year(s) Of Engagement Activity | 2017,2018 |
URL | http://www.nhm.ac.uk/our-science/courses-and-students/short-course-taxonomy-stratigraphy-cenozoic-pl... |
Description | Presentation at Geological Society of America conference (Seattle) |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Professional Practitioners |
Results and Impact | I presented the current state of my research at the GSA conference in Seattle |
Year(s) Of Engagement Activity | 2017 |
Description | Short course in taxonomy of Cenozoic planktonic foraminifera |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | National |
Primary Audience | Postgraduate students |
Results and Impact | 14 participants attended a week-long short course covering the taxonomy and ecology of Cenozoic macroperforate planktonic foraminifera, run by Prof Pearson (co-I), Prof Purvis (PI), Dr Tom Hill (NHM) and Prof Bridget Wade of UCL. The course was sufficiently popular that we proposed a short course to NERC to run the activity annually. |
Year(s) Of Engagement Activity | 2015 |