Geologically calibrated mammalian tree and its correlation with global events, including the emergence of humans
Abstract A robust timetree for Mammalia was constructed using the time calibration function of BEAST v1.10.4 and MEGA 11. The analysis involved the application of times of the most recent common ancestors, including a total of 19 mammalian fossil calibration ages following Benton et al. (Palaeontolo...
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| Format: | Article |
| Language: | English |
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Wiley
2023-12-01
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| Series: | Ecology and Evolution |
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| Online Access: | https://doi.org/10.1002/ece3.10827 |
| _version_ | 1797373099215159296 |
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| author | Soichi Osozawa |
| author_facet | Soichi Osozawa |
| author_sort | Soichi Osozawa |
| collection | DOAJ |
| description | Abstract A robust timetree for Mammalia was constructed using the time calibration function of BEAST v1.10.4 and MEGA 11. The analysis involved the application of times of the most recent common ancestors, including a total of 19 mammalian fossil calibration ages following Benton et al. (Palaeontologia Electronica, 2015, 1–106) for their minimum ages. Additionally, fossil calibration ages for Gorilla, Pan, and a geologic event calibration age for otters were incorporated. Using these calibration ages, I constructed a geologically calibrated tree that estimates the age of the Homo and Pan splitting to be 5.69 Ma. The tree carries several significant implications. First, after the initial rifting at 120 Ma, the Atlantic Ocean expanded by over 500 km around Chron 34 (84 Ma), and vicariant speciation between Afrotheria (Africa) and Xenarthra (South America) appears to have commenced around 70 Ma. Additionally, ordinal level differentiations began immediately following the K–Pg boundary (66.0 Ma), supporting previous hypothesis that mammalian radiation rapidly filled ecological niches left vacant by non‐avian dinosaurs. I constructed a diagram depicting the relationship between base substitution rate and age using an additional function in BEAST v1.10.4. The diagram reveals an exponential increase in the base substitution rate approaching recent times. This increased base substitution rate during the Neogene period may have contributed to the expansion of biodiversity, including the extensive adaptive radiation that led to the evolution of Homo sapiens. One significant driving factor behind this radiation could be attributed to the emergence and proliferation of C4 grasses since 20 Ma. These grasses have played a role in increasing carbon fixation, reducing atmospheric CO2 concentration, inducing global cooling, and initiating Quaternary glacial–interglacial cycles, thereby causing significant climatic changes. |
| first_indexed | 2024-03-08T18:45:29Z |
| format | Article |
| id | doaj.art-e4d52cc91b8b4a7ca2e0b061b0abb3ab |
| institution | Directory Open Access Journal |
| issn | 2045-7758 |
| language | English |
| last_indexed | 2024-03-08T18:45:29Z |
| publishDate | 2023-12-01 |
| publisher | Wiley |
| record_format | Article |
| series | Ecology and Evolution |
| spelling | doaj.art-e4d52cc91b8b4a7ca2e0b061b0abb3ab2023-12-29T00:26:16ZengWileyEcology and Evolution2045-77582023-12-011312n/an/a10.1002/ece3.10827Geologically calibrated mammalian tree and its correlation with global events, including the emergence of humansSoichi Osozawa0Faculty of Science, Institute of Geology and Paleontology Tohoku University Sendai JapanAbstract A robust timetree for Mammalia was constructed using the time calibration function of BEAST v1.10.4 and MEGA 11. The analysis involved the application of times of the most recent common ancestors, including a total of 19 mammalian fossil calibration ages following Benton et al. (Palaeontologia Electronica, 2015, 1–106) for their minimum ages. Additionally, fossil calibration ages for Gorilla, Pan, and a geologic event calibration age for otters were incorporated. Using these calibration ages, I constructed a geologically calibrated tree that estimates the age of the Homo and Pan splitting to be 5.69 Ma. The tree carries several significant implications. First, after the initial rifting at 120 Ma, the Atlantic Ocean expanded by over 500 km around Chron 34 (84 Ma), and vicariant speciation between Afrotheria (Africa) and Xenarthra (South America) appears to have commenced around 70 Ma. Additionally, ordinal level differentiations began immediately following the K–Pg boundary (66.0 Ma), supporting previous hypothesis that mammalian radiation rapidly filled ecological niches left vacant by non‐avian dinosaurs. I constructed a diagram depicting the relationship between base substitution rate and age using an additional function in BEAST v1.10.4. The diagram reveals an exponential increase in the base substitution rate approaching recent times. This increased base substitution rate during the Neogene period may have contributed to the expansion of biodiversity, including the extensive adaptive radiation that led to the evolution of Homo sapiens. One significant driving factor behind this radiation could be attributed to the emergence and proliferation of C4 grasses since 20 Ma. These grasses have played a role in increasing carbon fixation, reducing atmospheric CO2 concentration, inducing global cooling, and initiating Quaternary glacial–interglacial cycles, thereby causing significant climatic changes.https://doi.org/10.1002/ece3.10827base substitution rateBEAST v1.10.4environmental changesfossil calibrationmammals |
| spellingShingle | Soichi Osozawa Geologically calibrated mammalian tree and its correlation with global events, including the emergence of humans Ecology and Evolution base substitution rate BEAST v1.10.4 environmental changes fossil calibration mammals |
| title | Geologically calibrated mammalian tree and its correlation with global events, including the emergence of humans |
| title_full | Geologically calibrated mammalian tree and its correlation with global events, including the emergence of humans |
| title_fullStr | Geologically calibrated mammalian tree and its correlation with global events, including the emergence of humans |
| title_full_unstemmed | Geologically calibrated mammalian tree and its correlation with global events, including the emergence of humans |
| title_short | Geologically calibrated mammalian tree and its correlation with global events, including the emergence of humans |
| title_sort | geologically calibrated mammalian tree and its correlation with global events including the emergence of humans |
| topic | base substitution rate BEAST v1.10.4 environmental changes fossil calibration mammals |
| url | https://doi.org/10.1002/ece3.10827 |
| work_keys_str_mv | AT soichiosozawa geologicallycalibratedmammaliantreeanditscorrelationwithglobaleventsincludingtheemergenceofhumans |