Overkill Hypothesis

This paper addresses misrepresentations and errors in attacks directed against the Overkill hypothesis that was proposed by Paul Martin to explain selective late Pleistocene extinctions. The opposing Climate-Change hypothesis to explain extinctions is driven by ideology as much as by objective reasoning because it is repeated so frequently without strong new evidence to support it, but it has failed to nail down a victory in public opinion. Overkill, which is not an anti-climate-change hypothesis, is perhaps too ''flexible'' to persuade all scientists, especially because negative evidence (a lack of megafaunal killsites) is considered to be as corroborative as positive evidence. Multiphase models of extinctions that propose different genera died out at different times have become less and less likely as more radiometric dating is done, and overlook the documented variability in atmospheric radiocarbon around the end of the Pleistocene, which prevents the high resolution chronology-building necessary to support a discontinuous model of the extinctions. The extinctions were geologically abrupt, selective, and unique, and therefore they require unique explanations. r

For hundreds of millions of years, large vertebrates (megafauna) have inhabited most of the ecosystems on our planet. During the late Quaternary, notably during the Late Pleistocene and the early Holocene, Earth experienced a rapid extinction of large, terrestrial vertebrates. While much attention has been paid to understanding the causes of this massive megafauna extinction, less attention has been given to understanding the impacts of loss of megafauna on other organisms with whom they interacted. In this review, we discuss how the loss of megafauna disrupted and reshaped ecological interactions, and explore the ecological consequences of the ongoing decline of large vertebrates. Numerous late Quaternary extinct species of predators, parasites, commensals and mutualistic partners were associated with megafauna and were probably lost due to their strict dependence upon them (co-extinctions). Moreover, many extant species have megafauna-adapted traits that provided evolutionary benefits under past megafauna-rich conditions, but are now of no or limited use (anachronisms). Morphological evolution and behavioural changes allowed some of these species partially to overcome the absence of megafauna. Although the extinction of megafauna led to a number of co-extinction events, several species that likely co-evolved with megafauna established new interactions with humans and their domestic animals. Species that were highly specialized in interactions with megafauna, such as large predators, specialized parasites, and large commensalists (e.g. scavengers, dung beetles), and could not adapt to new hosts or prey were more likely to die out. Partners that were less megafauna dependent persisted because of behavioural plasticity or by shifting their dependency to humans via domestication, facilitation or pathogen spill-over, or through interactions with domestic megafauna. We argue that the ongoing extinction of the extant megafauna in the Anthropocene will catalyse another wave of co-extinctions due to the enormous diversity of key ecological interactions and functional roles provided by the megafauna.

This paper addresses misrepresentations and errors in attacks directed against the Overkill hypothesis that was proposed by Paul Martin to explain selective late Pleistocene extinctions. The opposing Climate-Change hypothesis to explain extinctions is driven by ideology as much as by objective reasoning because it is repeated so frequently without strong new evidence to support it, but it has failed to nail down a victory in public opinion. Overkill, which is not an anti-climate-change hypothesis, is perhaps too ''flexible'' to persuade all scientists, especially because negative evidence (a lack of megafaunal killsites) is considered to be as corroborative as positive evidence. Multiphase models of extinctions that propose different genera died out at different times have become less and less likely as more radiometric dating is done, and overlook the documented variability in atmospheric radiocarbon around the end of the Pleistocene, which prevents the high resolution chronology-building necessary to support a discontinuous model of the extinctions. The extinctions were geologically abrupt, selective, and unique, and therefore they require unique explanations.

Today the influence of man on his environment is evident. The limited number of free living large mammals in
Central Europe is the result of this influence. The process leading to the current situation is generally not well
known. A comparison of the large mammal fauna that lived in Central Europe during the last interglacials and
today’s fauna illustrates man’s influence in prehistory and, in addition, the potential for living fauna today, if the
political will were there. Keywords: Fauna, climate, overkill hypothesis, climate hypothesis, extinction.

For hundreds of millions of years, large vertebrates (megafauna) have inhabited most of the ecosystems on our planet. During the late Quaternary, notably during the Late Pleistocene and the early Holocene, Earth experienced a rapid extinction of large, terrestrial vertebrates. While much attention has been paid to understanding the causes of this massive megafauna extinction, less attention has been given to understanding the impacts of loss of megafauna on other organisms with whom they interacted. In this review, we discuss how the loss of megafauna disrupted and reshaped ecological interactions, and explore the ecological consequences of the ongoing decline of large vertebrates. Numerous late Quaternary extinct species of predators, parasites, commensals and mutualistic partners were associated with megafauna and were probably lost due to their strict dependence upon them (co-extinctions). Moreover, many extant species have megafauna-adapted traits that provided evolutionary bene...

Aim: To provide a detailed analysis and interpretation of cranial and postcranial lesions noted on an early medieval skeleton from the Italian Alps.
Materials: Individual (SK63) was buried within the early Christian church (5th-8th centuries AD) of Säben-Sabiona in South Tyrol (Italy).
Methods: The skeleton underwent macroscopic, microscopic and metric analyses.
Results: SK63 was a 19-25 year old male, the analysis identified at least 29 lesions, consisting of three possible antemortem injuries and 26 perimortem sharp force injuries on the cranium (n=4) and postcranium (n=22).
Conclusions: The trauma pattern observed indicates that different bladed weapons were used and interpersonal violence rather than a large- scale conflict led to the death of SK63.
Significance: The present findings provide novel information on violent interpersonal interactions in early medieval Säben-Sabiona, Italy.
Limitations: The sequence of the inflicted injuries was not reconstructed. 
Suggestions for Further Research: Future interdisciplinary investigations (i.e., 3D imaging and reconstructions) will aid a better understanding of the possible types of weapons used to inflict injuries, the required forces to create the lesions, as well as the directions of impact.