scholarly journals Reciprocal altruism may have evolved by accident

2022 ◽  
Author(s):  
Sergio Da Silva ◽  
Sergio Bonini
Keyword(s):  
Intertemporal Choice ◽  
Reciprocal Altruism ◽  
Survival And Reproduction ◽  
New Hypothesis

The most accepted explanation for the evolution of reciprocal altruism is based on cooperative reciprocators engaged in intertemporal choice. Here, we parsimoniously dismiss this narrative and suggest a new hypothesis based on random encounters of selfish individuals that result in theft. Theft can coexist with passive reactions on the victims, as it does not jeopardize survival and reproduction in times of abundance. As a result, offspring with psychological adaptations of not reacting to theft can become reliable reciprocators amid scarcity.

scholarly journals Fitness benefits of dietary restriction

2021 ◽  
Vol 288 (1963) ◽  
Author(s):  
Zahida Sultanova ◽  
Edward R. Ivimey-Cook ◽  
Tracey Chapman ◽  
Alexei A. Maklakov
Keyword(s):  
Dietary Restriction ◽  
Early Life ◽  
Total Fecundity ◽  
Wide Range ◽  
Evolutionarily Conserved ◽  
Food Shortages ◽  
Survival And Reproduction ◽  
Reduced Costs ◽  
Sufficient Magnitude ◽  
New Hypothesis

Dietary restriction (DR) improves survival across a wide range of taxa yet remains poorly understood. The key unresolved question is whether this evolutionarily conserved response to temporary lack of food is adaptive. Recent work suggests that early-life DR reduces survival and reproduction when nutrients subsequently become plentiful, thereby challenging adaptive explanations. A new hypothesis maintains that increased survival under DR results from reduced costs of overfeeding. We tested the adaptive value of DR response in an outbred population of Drosophila melanogaster fruit flies. We found that DR females did not suffer from reduced survival upon subsequent re-feeding and had increased reproduction and mating success compared to their continuously fully fed (FF) counterparts. The increase in post-DR reproductive performance was of sufficient magnitude that females experiencing early-life DR had the same total fecundity as continuously FF individuals. Our results suggest that the DR response is adaptive and increases fitness when temporary food shortages cease.

A New Hypothesis About Schizophrenia

2002 ◽  
Author(s):  
H. W. Moises ◽  
T. Zoega ◽  
I. I. Gottesman
Keyword(s):  
New Hypothesis

Probabilistic Intertemporal Choice and Framing Effects

2002 ◽  
Author(s):  
Tamar R. Malinek ◽  
Daniel M. Oppenheimer
Keyword(s):  
Intertemporal Choice ◽  
Framing Effects

On the origin of khutū

2008 ◽  
Vol 35 (2) ◽  
pp. 306-318 ◽  
Author(s):  
C. LAVERS ◽  
M. KNAPP
Keyword(s):  
Twentieth Century ◽  
Medieval Literature ◽  
Ice Age ◽  
New Hypothesis

Khutū was a material derived from an animal used by Medieval Asian peoples in the manufacture of knife handles and as an alexipharmic. Al-Bīrūnī (973–1048) made extensive enquiries into the origin of khutū but reached no definite conclusion. Literary scholars in the first half of the twentieth century identified the walrus and narwhal as probable sources, but in ignoring aspects of the literature on khutū’s appearance and provenance left a number of questions unanswered. We clarify and extend this research and identify further clues to the identity of khutū. We concur that walrus ivory was one source of khutū, suggest that the remains of “Ice Age” mammals may have influenced development of the medieval literature on khutū more than previous investigators realized, and offer a new hypothesis of khutū’s origin.

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