lunes, abril 05, 2010

Behavioral development not Genetic Kin Selection!...may explain origins of sociality



It has been proposed that one of the traits that are involved in the origin of sociality is the tolerance among individuals belonging to the same species. This means that the transition from solitary to social life requires the regulation of aggressiveness and the evolution of intraspecific recognition. This is also known as kin recognition, now, when we look at the ideas to explain the origin and maintenance of this trait, there are some contrasting approaches.

The sociobiological school, propose that individuals bearing the same genes may be able to recognize themselves, this correspond to an evolutionary adaptation that allow them to collaborate and keep cohesion of related group of individual. This idea has flourished in the field of behavioral ecology and the mainstream neodarwinian culture, it has been suggested even to explain altruism in humans. However, despite the benefits suggested on the theoretical models for a genetic kin selection, these proposals are often not supported with explanatory mechanism for the occurrence of such kin recognition.

Alternatively to this approach, it have been suggested that the recognition and acceptance of individuals belonging to a defined group correspond to an emergent property due to behavioral development, where the signals present during the construction of the kin fidelity responses are molded by the available cues, these cues can originated either in the group (kin reference) or even derive from the organism itself that is developing its responses (self reference).





One suitable system to study the jump from solitary to social life and the origin and maintenance of intraspecific recognition is constituted by the Xylocopinae (Hymenoptera: Apidae). This group is held as the sister group for all other Apidae subfamilies, and thus it may very likely be the less derived. In addition it contains species that goes from solitary to social life in relation to nesting behavior. Among the solitary species some exhibit features more often present in social species, some of these are related to parental care, contact between related individuals and also tolerance between nestmates. Manueli apostica is one of these solitary bees, it belong to the monogenerial tribe Manuelini inside Xylocopine, a group mainly presented on continental Chile. In these bees, female construct nests inside the dead stem of Chusquea quila (Poaceae: Bambuseae), in these developing offspring are isolated by the mother in single compartments together with food supplies (Figure 1).

In this group, Dr. Luis Flores-Prado and collaborators from Facultad de Ciencias, Universidad de Chile,  have found that the recognition of nestmates individuals and tolerance is either developed from cues present on food masses and nest material provided by the mother or on cues acquired by the insect themselves, also known as self referencing (Experiment 1, Figure 2). In a newly published research Dr Flores-Prado and co. performed a recognition test between two non-kin individuals (a foster and a non manipulated one, Experiment 2, comparison A) developed in the same nest, thus they will experience the same breeding environment.

Furthermore, they compared between two kin females developed in different nest, which were not used as sources of other test (Experiment 2, comparison B). So, this means same kin different environment.





These transplant design allow them to disentangle if kin recognition is achieved due to the cues from food provisioning or from cues that the bee obtain from itself. These experiments demonstrated that non-kin females developed in the same nest were more intolerant (and less tolerant) with each other than kin females developed in different nests (Figure 3). Thus, kin recognition was occurring. Individuals of M. postica are physically isolated while developing up to the adult stage prior to the destruction of cell partitions, and there is no direct contact between them and their mother after oviposition. In addition, non-volatile compounds (such as cuticular hydrocarbons) mediate nesmate recognition in this specie (at has been demonstrated by Dr. Flores-Prado). Based on these evidences the authors suggest that cues used in this “kin” recognition do not correspond to an especially unique kin cues and that kin recognition in this bee specie has occurred through self-referent phenotype matching. Just in the same way chicken embryos are able to develop its how-to-peek on a spot behavior due to the cues derived from the movements of their own organs inside the egg, one of the many amazing examples of behavioral developments discovered by Z.Y. Kuo in the beginning of the XX century. 



Cristian Villagra 




References

Flores-Prado L Chiappa E & Niemeyer HM Nesting biology, life cycle, and interactions between females of Manuelia postica, a solitary species of the Xylocopinae (Hymenoptera: Apidae). 35:93-102.

Flores-Prado, L. Aguilera-Olivares D. & Niemeyer H.M. 2008 Nest-mate recognition in Manuelia postica (Apidae: Xylocopinae): an eusocial trait is present in a solitary bee. Proc. R. Soc. B 275, 285–291.

Flores-Prado L & Niemeyer HM 2010 Kin Recognition in the largely Solitary Bee, Manuelia postica (Apidae: Xylocopinae). Ethology 115:1–6.

Hamilton, W. D. 1964a The genetical evolution of social behavior, I. J. Theor. Biol. 7, 1–16.

Hamilton, W. D. 1964b The genetical evolution of social behavior, II. J. Theor. Biol. 7, 17–52.

Mateo, J. M. 2004: Recognition systems and biologicalorganisation: the perception component of social recognition.Ann. Zool. Fenn. 41, 729-745.

Michener CD 2000. The bees of the world. Baltimore, Maryland, The John Hopkins University Press. 913 p.



7 comentarios:

A. Vargas dijo...

I don't get it, that experiment just shows its not getting cues from the nest. It does not tell us anything about the mechanism of kin recognition. Self-recognition is a hypothesis, but it is not being tested by that experiment.

As it is, I think a hamiltonian could perfectly love this

Cobalto dijo...

MMm, i may have to extend the explanation, cos the missing link is that earlier experiments already demonstrated that the recognition is due to cuticular hydrocarbons.

when you have the isolated imago, they experience its own cuticular cues then it recognize kin due to that--

Cobalto dijo...

anyway hopefully we will have the author to explain those details...

Anónimo dijo...

ESTE JUEVES A LAS 6PM LUIS FLORES-PRADO PRESENTARA SU TRABAJO EN EL RAYO NO SE LO PIERDAN!

Feña dijo...

Gracias Diablo por invitar a Luis al Rayo. Estuvo realmente interesante.
Lamento haberme tenido que ir antes de que terminara la discusión final, pero me quedé pensando en el adelanto ontogenético en el que se hace contacto con la madre en abejas eusociales, que en el fondo es desde el inicio de la ontogenia, ya que la abeja ovipone directamente en la celda... y no puedo dejar de ver nuestra tan conocida retención del gérmen en el fenómeno, como condición más derivada, que aumenta la complejidad del ser vivo, y como patrón común de la evolución biológica.
Sería bonito encontrar el gradiente que posiblemente existe en el fenómeno: los taxa con bolas de comida grandes donde la hembra oviposita, y que el contacto con la madre es tardío, en bichos solitarios... Otros taxa tendrán estas bolas de comida más pequeñas, y por ende el contacto con la madre será antes en la ontogenia del gérmen, y por tanto, incrementaría en algún grado la sociabilidad, y así, hasta las que no tienen este bolo y la mamá es la esclava del germen comilón del cual no se quiso separar por mamona o por cualquier otra causa...
Bueno... Lo otro interesante es que, según contaba Luis, este sería un fenómeno tremendamente plástico, dependiente de variables ambientales, y por tanto, el escenario ideal para que la variación sea víctima de la canalización... Y vengamos nosotros después con nuestros hermosos métodos de clasificación.

Anónimo dijo...

Si, efectivamante me parace a mi tambien que la condicion emergente de autoreconocimiento pesente en grupos que no son eusoiciales puede ser la puerta de entrada a canalizaciones en la direccion un aumento de las fuentes que influencian el proceso de reconocimiento e interaccion intraspecifica. Al parecer al aumentar la socialidad las interacciones transgeneracionales se hacen mas robustas (retenedoras) y con mayor contenido de herencia cultural o induccion de plasticidades conductuales y morfologicas (como es el caso de las diferencias que se encuentran entre castas). Muy buena la presentacion de Luis creo que todos aprendimos bastante!...

Cristian

Inspector Clouseau dijo...

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