Presumably, a wider the range of body sizes moving from
autotrophs to top predators in a system permits longer food chains.
Autotrophs, having no mouths, cannot drool, so the line '
autotrophs began to drool' may be accused of being misleading, as I am sure Dr Cooper would be among the first to point out.
If you had to choose, a good place to start the story would be with the
autotrophs.
Autotrophs are organisms that can create their own food, and many of them do it using photosynthesis.
Understanding how and when
autotrophs evolved may topple the popular idea that life originated in a primordial pool rich in amino acids and organic molecules.
Two major groups of microbes in the ocean play essential roles in transforming carbon compounds and moving them from the surface ocean to the deep ocean:
autotrophs such as phytoplankton, which produce organic carbon compounds, and heterotrophs such as bacteria, which recycle already-made organic carbon.
This generalization appears to be universal for all
autotrophs, including those that use the reductive TCA cycle (Fuchs, 1989), those that employ the oxidative TCA cycle (Nelson and Cox, 2000), and those with the "horseshoe," or incomplete, TCA cycle (Ljungdahl, 1986; Ragsdale, 1991).
This suggests that the primary determinant of the N:P of CNR is food N:P and that grazer body N:P is secondary, a reasonable conclusion given the likelihood that cellular elemental composition is considerably more variable (both intra- and interspecifically) for
autotrophs than for metazoans (Sterner and Hessen 1994).
In the course of studying biogenesis, we became aware of bacteria that were reductive
autotrophs and fixed carbon from carbon dioxide through the reductive tricarboxylic acid (rTCA) cycle (Fuchs, 1989).
In the first experiment, we constructed aquatic, microbial microcosms containing small numbers of
autotrophs (unicellular green algae) and decomposers (heterotrophic bacteria) and maintained them under uniform environmental conditions for many ([greater than]25) generations, but randomly varied the number of consumer species (heterotrophic protists) stocked in these replicate microcosms.
The case is somewhat puzzling because what it means is that mixotrophy is so important in regulating the food web that the mixotroph must survive as an
autotroph. In this case there would be no nutrient supply to mixotrophs via phagotrophy.
nov., a novel marine facultative
autotroph and the putative symbiont of Thasira flexuosa.
The data could also be used for future analyses of organic carbon energy flow, as well as for those examining the interannual variability of heterotrophic processes such as the energy flow from
autotrophs to heterotrophs.