Mammals on the EDGE: Conservation Priorities Based on Threat and Phylogeny
Nick J.B. Isaac, * Samuel T. Turvey, Ben Collen,Carly Waterman, and Jonathan E.M. Baillie
Walt Reid, Academic Editor
The National Library of Medicine (NLM) provides access to scientific literature but does not endorse or agree with the contents of the literature.
- Conservation priority setting based on phylogenetic diversity is proposed but rarely implemented.
- A new index called Evolutionary Distinctiveness (ED) measures the contribution of different species to phylogenetic diversity.
- The ED index is independent of clade size, making it comparable across different taxonomic groups.
- The approach is applied to a near-complete species-level phylogeny of mammals to generate a global priority list for conservation.
- The list includes many species not typically recognized as conservation priorities and highlights the need to reassess global conservation priorities.
- PD (Phylogenetic Diversity) has not gained wider acceptance in the conservation community due to a lack of complete phylogenetic data and a focus on endemic or threatened species.
- The new ED method incorporates both branch length data and conservation status to generate a prioritized list of species for conservation.
- The method is illustrated with an example of a clade of seven species, showing how ED scores are calculated based on the length of branches and the number of species subtending the branch.
- The example highlights that ED is not solely determined by a species' unique phylogenetic diversity but also considers the conservation of uncommon lineages.
- The ED calculation is similar to the Equal Splits measure, which apportions branch length equally among daughter clades.
Most species derive at least two-thirds of their Evolutionary Distinctiveness (ED) from the terminal branch, but the branch length is a poor predictor of total ED.
ED scores in primates are tightly correlated under different species concepts, but species that have been split into multiple species lose a large portion of their ED.
Mammal ED scores range from 0.0582 MY to 97.6 MY, with a median of 7.86 MY.
Least Concern species have significantly lower ED than other Red List categories, suggesting low extinction risk.
EDGE scores range from 0.0565 to 6.48, with a mean of 2.63. The top 100 priority species include large-bodied mammals and smaller, lesser-known species.
Threat status alone does not guarantee a high priority on the EDGE list
The method described in the text satisfies two conditions for conservation priority-setting: capturing biodiversity and being robust to uncertainty. It uses EDGE scores that incorporate species value and urgency of action. The scores are robust to clade size, missing species, poor phylogenetic resolution, and taxonomic uncertainty. The method is easy to calculate with Red List assessments and a phylogeny of at least 100 species. It is also robust to topology and branch length uncertainty in the phylogeny. The method could not assign EDGE scores to some Data Deficient species and species missing from the phylogeny, but these could be included in future assessments.
There is a debate about focusing conservation efforts on species with high evolutionary distinctiveness (ED) or low ED.
- It is uncertain whether we can accurately predict future evolutionary potential and there is no established relationship between phylogeny and diversity over time.
- ED can be a useful predictor of divergent properties and potential utilitarian value.
- Species with low ED scores tend to have low extinction risk and may survive the current extinction crisis without specific interventions.
- Focusing on lower risk species instead of high priority EDGE (Evolutionarily Distinct and Globally Endangered) species would result in a loss of major branches of the Tree of Life.
- Most mammalian conservation projects are aimed at charismatic megafauna and may not be sufficient to protect high priority EDGE species.
- Species not found in protected areas tend to have higher EDGE scores than those found inside protected areas.
- Many of the top 100 EDGE species have not had any species-specific conservation actions recommended for them.
- The lack of conservation attention for high priority EDGE species is a serious problem and suggests that a significant amount of evolutionary history may be lost.
- The approach described in this paper can be used for conservation in several ways, including prioritizing the management of the most evolutionarily distinct species, generating lists of high-priority species for urgent conservation action, and weighting species' importance in selecting reserve networks.
The EDGE approach identifies species that have the most evolutionary history and are in imminent danger of extinction.
- The approach extends the application of PD-based conservation to a wider range of taxa and situations.
- Future work could incorporate socioeconomic considerations and the extinction risk of a species' close relatives.
- Existing conservation measures inadequately serve large numbers of evolutionarily distinct species.
- A composite 'supertree' phylogeny was used to calculate ED scores for mammals.
- The phylogeny presents challenges due to poor resolution, missing species, and uncertainty in node ages.
- A scaling factor based on the empirical distribution of ED scores in a randomly generated phylogeny was applied to correct for the bias induced by polytomies.
- Missing species were taken into account and a correction factor was used to allocate them among their closest relatives.
- Variation in divergence times led to uncertainty in ED scores, so three sets of branch lengths were used to estimate ED.
- The geometric mean was used to calculate species values of ED to account for uncertainty.
ED scores were tested for comparability among taxonomic groups by examining how species' ED accumulates as larger clades are considered.
- The rank order of ED scores should be independent of the size of the clade considered if they are truly comparable.
- Ten Critically Endangered species from different mammal orders were randomly selected and their cumulative ED scores were measured at each node in the mammal supertree.
- Taxonomic changes can significantly alter the ED scores of individual species, particularly when species are split into multiple entities.
- The impact of taxonomic changes on ED scores was investigated using primates, which have recently undergone taxonomic inflation.
- ED scores were compared under a biological species concept (233 species) and a phylogenetic species concept (358 species) in primates.
- A single phylogeny was used, but the number of species represented by each tip was changed to calculate the expected ED for multi-species tips.
The table shows Evolutionary Distinctiveness (ED) and EDGE scores for mammal species.
- The species are ranked by their EDGE score, which is a measure of their conservation priority.
- The species taxonomy follows Wilson & Reeder.
- Red List categories are used to classify the conservation status of each species.
- Some species could not be assigned EDGE scores and are listed at the bottom of the table.
- There is also a table specifically for primates, which includes ED scores under the biological species concept and the number of phylogenetic species into which each biological species was split.
- ED scores are lower for phylogenetic species compared to biological species, even if their taxonomic status is the same under both concepts.
- This is because there are more total species in the phylogeny, so each one receives a smaller share of the ancestral branches' distinctiveness.
- The ED scores in the tables were calculated using one set of branch lengths
- The tables show the species' ED scores and EDGE scores for mammals, as well as their conservation status according to the Red List categories.
- The taxa used for classification follow Wilson & Reeder's taxonomy.
- Some species could not be assigned EDGE scores and are listed separately at the bottom of the table.
- There is a separate table specifically for primates, which includes ED scores under the biological species concept and the number of phylogenetic species into which each biological species was split.
- ED scores tend to be lower for phylogenetic species compared to biological species, even if their taxonomic status is the same under both concepts. This is because the total number of species in the phylogeny is higher, resulting in each species receiving a smaller share of the ancestral branches' distinctiveness.
- The ED scores in the tables were calculated using one set of branch lengths.
The paper titled "Mammals on the EDGE: Conservation Priorities Based on Threat and Phylogeny" discusses the concept of conservation priority setting based on phylogenetic diversity. Here are the key points discussed in the paper:
1. Conservation priority setting based on phylogenetic diversity is proposed but rarely implemented.
2. A new index called Evolutionary Distinctiveness (ED) measures the contribution of different species to phylogenetic diversity.
3. The ED index is independent of clade size, making it comparable across different taxonomic groups.
4. The approach is applied to a near-complete species-level phylogeny of mammals to generate a global priority list for conservation.
5. The list includes many species not typically recognized as conservation priorities and highlights the need to reassess global conservation priorities.
6. PD (Phylogenetic Diversity) has not gained wider acceptance in the conservation community due to a lack of complete phylogenetic data and a focus on endemic or threatened species.
7. The new ED method incorporates both branch length data and conservation status to generate a prioritized list of species for conservation.
8. The ED calculation is similar to the Equal Splits measure, which apportions branch length equally among daughter clades.
9. Most species derive at least two-thirds of their Evolutionary Distinctiveness (ED) from the terminal branch, but the branch length is a poor predictor of total ED.
10. ED scores in primates are tightly correlated under different species concepts, but species that have been split into multiple species lose a large portion of their ED.
11. Mammal ED scores range from 0.0582 MY to 97.6 MY, with a median of 7.86 MY.
12. Least Concern species have significantly lower ED than other Red List categories, suggesting low extinction risk.
13. EDGE scores (Evolutionarily Distinct and Globally Endangered) range from 0.0565 to 6.48, with a mean of 2.63. The top 100 priority species include large-bodied mammals and smaller, lesser-known species.
14. Threat status alone does not guarantee a high priority on the EDGE list.
15. The approach described in the paper captures biodiversity and is robust to uncertainty, making it suitable for conservation priority-setting.
16. The EDGE approach identifies species that have the most evolutionary history and are in imminent danger of extinction.
17. Future work could incorporate socioeconomic considerations and the extinction risk of a species' close relatives.
18. Existing conservation measures inadequately serve large numbers of evolutionarily distinct species.
19. The paper also discusses the challenges in constructing a phylogeny, such as poor resolution, missing species, and uncertainty in node ages.
20. Taxonomic changes can significantly alter the ED scores of individual species, particularly when species are split into multiple entities.
These are the key points discussed in the paper "Mammals on the EDGE: Conservation Priorities Based on Threat and Phylogeny".
The research paper titled "Mammals on the EDGE: Conservation Priorities Based on Threat and Phylogeny" discusses the application of phylogenetic diversity in setting conservation priorities for mammals. The paper introduces a new index called Evolutionary Distinctiveness (ED), which measures the contribution of different species to phylogenetic diversity. The ED index is independent of clade size, making it comparable across different taxonomic groups. The researchers applied this approach to a near-complete species-level phylogeny of mammals to generate a global priority list for conservation.
The paper highlights that traditional conservation priority-setting approaches, such as focusing on endemic or threatened species, have limitations due to a lack of complete phylogenetic data. The ED method overcomes these limitations by incorporating both branch length data and conservation status to generate a prioritized list of species for conservation. This method considers not only a species' unique phylogenetic diversity but also the conservation of uncommon lineages.
The paper also discusses the calculation of ED scores, which is similar to the Equal Splits measure. Most species derive at least two-thirds of their ED from the terminal branch, but the branch length is a poor predictor of total ED. Mammal ED scores range from 0.0582 MY to 97.6 MY, with a median of 7.86 MY. The paper also introduces EDGE scores, which combine both evolutionary distinctiveness and conservation urgency. The top 100 priority species identified by the EDGE scores include both large-bodied mammals and smaller, lesser-known species.
The paper emphasizes that conservation efforts focused solely on charismatic megafauna may not be sufficient to protect high priority EDGE species. It also highlights the lack of conservation attention for high priority EDGE species, suggesting a potential loss of evolutionary history. The authors propose that the approach described in the paper can be used for conservation in several ways, such as prioritizing the management of the most evolutionarily distinct species and generating lists of high-priority species for urgent conservation action.
The research paper acknowledges some challenges in applying the ED method, such as poor phylogenetic resolution, missing species, and uncertainty in node ages. The authors used a composite 'supertree' phylogeny to calculate ED scores for mammals, taking into account missing species and applying correction factors. The paper also discusses the impact of taxonomic changes on ED scores, particularly when species are split into multiple entities.
Finally, the paper presents tables showing Evolutionary Distinctiveness (ED) and EDGE scores for mammal species. The species are ranked based on their EDGE scores, which indicate their conservation priority. It also includes information on the Red List categories used to classify the conservation status of each species. Some species could not be assigned EDGE scores due to various reasons, and they are listed separately in the tables.
Overall, the paper provides insights into the application of phylogenetic diversity in conservation priority-setting for mammals and highlights the need to reassess global conservation priorities based on evolutionary distinctiveness.