commit a393808afb7bae7229b2a3f5cf119e8e84891ad5 Author: Stefan Dresselhaus Date: Sun Apr 22 00:55:17 2018 +0200 initial commit diff --git a/README.md b/README.md new file mode 100644 index 0000000..11160ee --- /dev/null +++ b/README.md @@ -0,0 +1,10 @@ +# Chemodiversity + +Project in the workgroup "theoretic biology" at the faculty of biology exploring +the evolution of plants secondary metabolities (PSM) via simulation. + +References: + +- [Moore et al (2013): Explaining intraspecific diversity in plant secondary metabolites in an ecological context](https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.12526) +- [Firn, Jones (2003): Natural products – a simple model to explain chemical diversity](http://www.caryinstitute.org/sites/default/files/public/reprints/Firn_&_Jones_2003_Natural_RSC_Nat_Prod_Rep_20_382-391.pdf) + diff --git a/sketch.md b/sketch.md new file mode 100644 index 0000000..de409d5 --- /dev/null +++ b/sketch.md @@ -0,0 +1,110 @@ +--- +title: Sketch for simulating chemodiversity +author: Stefan Dresselhaus +date: 2018-09-21 +format: markdown+lhs + +... + += (rough) sketch components responsible for chemodiversity + +== Genes + +- define which enzymes are produced in which quantities + - list in fig. 1 in [1] +- can be scaled down/inactivated (i.e. when predators leave for generations) + - easy to ramp up production as long as the genes are still there +- plants can survive without problems with inactive PSM-cycles when no + adversaries are present. + +=== Inheritance & Mutation + +- via whole-genome and local-genome duplication +- copies accumulate mutations that lead to neofunctionalization +- e.g. subtle differences in terpene synthases can yield vastly different products + - i.e. these changes can appear easily + - need to classify products by "chemical distance" for simulation + - **TODO**: Map/Markov-Chain of mutations that may occur here? + +=== Evolutional strategies + +- "Bet-hedging": reduce variations of fitness over time + - **TODO**: understand + - different effects of intra-cohort-variation vs. inter-cohort-variation +- Plants with inactive PSM can survive if predators are deterred by other + individuals due to automimicry-effect which *could* foster wider genetic + variance + - the more of those individuals are present in a population, the less their + overall fitness becomes. + - **TODO**: fitness must also be able to depend on relative appearance of + adversarial traits in the population + - Keyword: Frequency-dependent-selection (FDS) + +== Pathways to produce chemical compounds + +- 40k+ compounds just stem from compounds of the calvin-cycle taking the + MEP-pathway or from the krebs-cycle taking the MVA-pathway + - both yield the same intermediate product that forms the basis. +- 10k+ compounds are amino-acid-derivatives +- Chapter VI in [1] exemplary describes 4 complete different pathways that yield + compounds. + - similar compounds/pathways should be found in the simulation + +=== Consequences of producing compounds + +- taking away parts of the calvin/krebs cycle puts pressure on those + - **TODO**: find out what they do and on what they depend. +- **TODO**: where do amino-acids come from? How much impact has the diversion of + these components? + +== Maintaining chemical diversity + +=== + screening hypothesis + +- many PSM found have no *known* biological activity +- plants "keep them around" in case another mutation needs them to produce + something "useful" +- creating things without use increase the need for photosynthesis and/or + nutrient uptake. + +=== - screening hypothesis + +- it is suggested that local abiotic & biotic selection pressures are the main + driver +- inactive molecules are not maintained long +- it was observed that some plants "rediscovered" some compounds in their + evolution suggesting they got rid of them when no pressure to maintain them + was applied + +==== questions resulting from this that should be answered in the simulation + +- details in chapter VIII of [1] +- how quick can lost diversity be restored? +- how expensive is it to keep producing many inactive substances while also + producing active deterrents? Does this lead to a single point-of-failure due + to overspecialisation? What must be done to prevent this? +- strong selection pressure *should* decrease quantity of compounds due to + costs, but plants do not seem to care. + - is this diversity needed in presence of multiple different adversaries? + - does the simulation specialize when only presented with one adversary? + What about adaptive adversaries? + - adaptation in the qualitative & quantitative evolution in response to + changed pressure? (i.e. those who cannot adapt quick enough die?) + += Scenario + +== Plants + +> data Foo = Bar + +== Enzymes + +== Herbivores + +== Environment + +== Fitness + +== Mating & Creation of diversity + + diff --git a/sketch.pdf b/sketch.pdf new file mode 100644 index 0000000..4262a4a Binary files /dev/null and b/sketch.pdf differ