BACKGROUND Mimicry, in which one prey species (the Mimic) imitates the aposematic signals of another prey (the Model) to deceive their predators, has attracted the general interest of evolutionary biologists. Predator psychology, especially how the predator learns and forgets, has recently been recognized as an important factor in a predator-prey system. This idea is supported by both theoretic...

We describe a model for the evolutionary consequences of plasticity in an environmentally heterogeneous metapopulation in which specialists for each of two alternative environments and one plastic type are initially present. The model is similar to that proposed by Moran (1992) but extends her work to two sites. We show that with migration between sites the plastic type is favored over local sp...

A cooperative group can achieve more than the sum of its members. Evolution has taken advantage of this principle in most natural systems, from multicellular individuals to ant colonies. To do so, it has provided the members of cooperative groups with communication tools, which are critical for effective cooperation. For example, some ants form bridges with their bodies to help their nest-mates...

Tissues of long-lived multicellular organisms have to maintain a constant number of functioning cells for many years. This process is called homeostasis. Homeostasis breaks down when cells emerge with mutations in tumor suppressor genes or oncogenes. Such mutated cells can have increased net rates of proliferation, which is increased somatic fitness. We show that the best protection against suc...

Learning is a fundamental biological adaptation that is widespread throughout the animal kingdom. According to previous research, two conditions are necessary for learning to be adaptive: between-generation environmental variability and withingeneration environmental predictability. In this paper, we show that between-generation variability is not necessary, and that instrumental learning can p...

Humans regularly provide others with resources at a personal cost to themselves. Chimpanzees engage in some cooperative behaviors in the wild as well, but their motivational underpinnings are unclear. In three experiments, chimpanzees (Pan troglodytes) always chose between an option delivering food both to themselves and a partner and one delivering food only to themselves. In one condition, a ...

A few colors, such as red and yellow, are commonly found in aposematic (warning) signaling across taxa, independent of evolutionary relationships. These colors have unique traits (i.e., hue, brightness) that aid in their differentiation, and perhaps, their effectiveness in promoting avoidance learning. This repeated use calls into question the influence of selection on specific warning colors a...

The phase behavior of mixed lipid dispersions representing the inner leaflet of the cell membrane has been characterized by X-ray diffraction. Aqueous dispersions of phosphatidylethanolamine:phosphatidylserine (4:1 mole/mole) have a heterogeneous structure comprising an inverted hexagonal phase H(II) and a lamellar phase. Both phases coexist in the temperature range 20-45 degrees C. The fluid-t...

In this paper, we study the auction model for resource management using the SimGrid simulation framework. We investigate three types of auction allocation protocols: (i) First-Price Auction, (ii) Vickrey Auction and (iii) Double Auction. The goal is to find which one is best suitable for the grid environment from users’ perspective as well as from resources’ perspective. The results showed that...