Re: [evol-psych] Paper: Symbiosis catalyses niche expansion and diversification
From: Robert Karl Stonjek <stonjek@...>
To: Evolutionary-Psychology <email@example.com>; Evolutionary Psychology News <firstname.lastname@example.org>
Sent: Thu, February 14, 2013 6:51:48 AM
Subject: [evol-psych] Paper: Symbiosis catalyses niche expansion and diversification
Symbiosis catalyses niche expansion and diversificationJeffrey B. Joy1,21Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia, Canada V5A 1S62Centre for Interdisciplinary Research in the Mathematical and Computational Sciences (IRMACS) Burnaby, British Columbia, Canada V5A 1S6e-mail: jbjoy@...
Interactions between species are important catalysts of the evolutionary processes that generate the remarkable diversity of life. Symbioses, conspicuous and inherently interesting forms of species interaction, are pervasive throughout the tree of life. However, nearly all studies of the impact of species interactions on diversification have concentrated on competition and predation leaving unclear the importance of symbiotic interaction. Here, I show that, as predicted by evolutionary theories of symbiosis and diversification, multiple origins of a key innovation, symbiosis between gall-inducing insects and fungi, catalysed both expansion in resource use (niche expansion) and diversification. Symbiotic lineages have undergone a more than sevenfold expansion in the range of host-plant taxa they use relative to lineages without such fungal symbionts, as defined by the genetic distance between host plants. Furthermore, symbiotic gall-inducing insects are more than 17 times as diverse as their non-symbiotic relatives. These results demonstrate that the evolution of symbiotic interaction leads to niche expansion, which in turn catalyses diversification.
Source: The Royal Society
This is one reason I repeat the phrase ecological, social, neurogenic, and socio-cognitive niche construction in the context of:
An epigenetic continuum from microbes to humans: from theory to facts
"Among different bacterial species existing in similar environments, DNA uptake (Palchevskiy & Finkel, 2009) appears to have epigenetically ‘fed’ interspecies methylation and speciation via conjugation (Fall et al., 2007; Finkel & Kolter, 2001; Friso & Choi, 2002). This indicates that reproduction began with an active nutrient uptake mechanism in heterospecifics and that the mechanism evolved to become symbiogenesis in the conspecifics of asexual organisms (Margulis, 1998). In yeasts, epigenetic changes driven by nutrition might then have led to the creation of novel cell types, which are required at evolutionary advent of sexual reproduction (Jin et al., 2011). These epigenetic changes probably occur across the evolutionary continuum that includes both nutrition-dependent reproduction in unicellular organisms and sexual reproduction in mammals. For example, ingested plant microRNAs influence gene expression across kingdoms (Zhang et al., 2012). In mammals, this epigenetically links what mammals eat to changes in gene expression (McNulty et al., 2011) and to new genes required for the evolutionary development of the mammalian placenta (Lynch, Leclerc, May, & Wagner, 2011) and the human brain (Zhang, Landback, Vibranovski, & Long, 2011)."Obviously, organisms compete for nutrients in their ecological niche, which is why "These results demonstrate that the evolution of symbiotic interaction leads to niche expansion, which in turn catalyses diversification." What else could be causal to diversification? (That was a rhetorical question.) The answer is not mutations; that's a ridiculous theory of cause.
James V. Kohl
Medical laboratory scientist (ASCP)
Kohl, J.V. (2012) Human pheromones and food odors: epigenetic influences on the socioaffective nature of evolved behaviors. Socioaffective Neuroscience & Psychology, 2: 17338.