14 August 2007

Definitia liberului arbitru

Free will commonly entails not only the subjective notion of willing to do something, but also that nobody but myself would be able to predict my behavior. … Along those lines, in the Behavioral Sciences one may therefore want to define free will a little differently. For an individual to possess free will, it would only require that: (1) all of the causes of the behavior are intra-individual and (2) the individual's behaviors are not predictable (within a level of scientific certainty) by someone else who is extra-individual. It is not that difficult to satisfy both requirements, depending on how certain of the above terms are defined. This definition explicitly does not touch the subjective feeling of free will, which I think is an advantage. This definition would allow for a conversion of free will from a philosophical question to a biological study area. The subjective experience of free will would then, consequentially, fall into the topic of consciousness.
Björn Brembs

12 August 2007

Un parazit care ataca creierul furnicilor

Articolul pe larg.
The spores of the fungus attach themselves to the external surface of the ant, where they germinate. They then enter the ant's body through the tracheae (the tubes through which insects breathe), via holes in the exoskeleton called spiracles. Fine fungal filaments called mycelia then start to grow inside the ant's body cavity, absorbing the host's soft tissues but avoiding its vital organs. When the fungus is ready to sporulate, the mycelia grow into the ant's brain. The fungus then produces chemicals which act on the host's brain and alter its perception of pheromones. This causes the ant to climb a plant and, upon reaching the top, to clamp its mandibles around a leaf or leaf stem, thus securing it firmly to what will be its final resting place. The fungus then devours the ant's brain, killing the host. The fruiting bodies of the fungus sprout from the ant's head, through gaps in the joints of the exoskeleton. Once mature, the fruiting bodies burst, releasing clusters of capsules into the air. These in turn explode on their descent, spreading airborne spores over the surrounding area. These spores then infect other ants, completing the life cycle of the fungus. Depending on the type of fungus and the number of infecting spores, death of an infected insect takes between 4-10 days.

08 August 2007

Interviuri facute de Susan Blackmore

Cateva interviuri din ultima carte a lui Susan Blackmore, "Conversations on Consciousness: What the Best Minds Think about the Brain, Free Will, and What It Means to Be Human" puse pe site-ul Guardian: - Francis Crick - Daniel Dennett - V.S. Ramachandran

04 August 2007

Ciori care folosesc unelte

Cioara este primul animal (in afara de om) care a fost observat fabricand unelte.

In laborator (cioara are la dispozitie mai intai o sarma dreapta, pe care, dupa cateva incercari nereusite, se decide sa o transforme intr-un carlig):

Si in natura:

Dar poate inca si mai spectaculos este felul in care s-au adaptat la mediul urban: link