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An ecometric analysis of the fossil mammal record of the Turkana Basin

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ABSTRACT

Although ecometric methods have been used to analyse fossil mammal faunas and environments of Eurasia and North America, such methods have not yet been applied to the rich fossil mammal record of eastern Africa. Here we report results from analysis of a combined dataset spanning east and west Turkana from Kenya between 7 and 1 million years ago (Ma). We provide temporally and spatially resolved estimates of temperature and precipitation and discuss their relationship to patterns of faunal change, and propose a new hypothesis to explain the lack of a temperature trend. We suggest that the regionally arid Turkana Basin may between 4 and 2 Ma have acted as a ‘species factory’, generating ecological adaptations in advance of the global trend. We show a persistent difference between the eastern and western sides of the Turkana Basin and suggest that the wetlands of the shallow eastern side could have provided additional humidity to the terrestrial ecosystems. Pending further research, a transient episode of faunal change centred at the time of the KBS Member (1.87–1.53 Ma), may be equally plausibly attributed to climate change or to a top-down ecological cascade initiated by the entry of technologically sophisticated humans.

This article is part of the themed issue ‘Major transitions in human evolution’.

No MeSH data available.


(a–d) Visualization of the modern-day data used for modelling.
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RSTB20150232F10: (a–d) Visualization of the modern-day data used for modelling.

Mentions: Figure 10 visualizes our modelling data from modern-day Africa within 25 degrees of the Equator. To minimize potential noise in the signal our modelling data excludes grid cells with less than three species, and cells with missing values for LOP (rare Primates; concern less than 0.5% of the grid cells). The data that are visualized in figure 10 have been used for inferring models.Figure 10.


An ecometric analysis of the fossil mammal record of the Turkana Basin
(a–d) Visualization of the modern-day data used for modelling.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4920289&req=5

RSTB20150232F10: (a–d) Visualization of the modern-day data used for modelling.
Mentions: Figure 10 visualizes our modelling data from modern-day Africa within 25 degrees of the Equator. To minimize potential noise in the signal our modelling data excludes grid cells with less than three species, and cells with missing values for LOP (rare Primates; concern less than 0.5% of the grid cells). The data that are visualized in figure 10 have been used for inferring models.Figure 10.

View Article: PubMed Central - PubMed

ABSTRACT

Although ecometric methods have been used to analyse fossil mammal faunas and environments of Eurasia and North America, such methods have not yet been applied to the rich fossil mammal record of eastern Africa. Here we report results from analysis of a combined dataset spanning east and west Turkana from Kenya between 7 and 1 million years ago (Ma). We provide temporally and spatially resolved estimates of temperature and precipitation and discuss their relationship to patterns of faunal change, and propose a new hypothesis to explain the lack of a temperature trend. We suggest that the regionally arid Turkana Basin may between 4 and 2 Ma have acted as a ‘species factory’, generating ecological adaptations in advance of the global trend. We show a persistent difference between the eastern and western sides of the Turkana Basin and suggest that the wetlands of the shallow eastern side could have provided additional humidity to the terrestrial ecosystems. Pending further research, a transient episode of faunal change centred at the time of the KBS Member (1.87–1.53 Ma), may be equally plausibly attributed to climate change or to a top-down ecological cascade initiated by the entry of technologically sophisticated humans.

This article is part of the themed issue ‘Major transitions in human evolution’.

No MeSH data available.