bio

clade

Links:

• https://en.wikipedia.org/wiki/Polyphyly

mineral, plant, animal, man

" Schumacher makes a restatement of the traditional chain of being.

He agrees with the view that there are four kingdoms: Mineral, Plant, Animal, Man. He argues that there are critical differences of kind between each level of being. Between mineral and plant is the phenomenon of life ... For Schumacher, a similar jump in level of being takes place between plant and animal, which is differentiated by the phenomenon of consciousness. We can recognise consciousness, not least because we can knock an animal unconscious, but also because animals exhibit at minimum primitive thought and intelligence.

The next level, according to Schumacher, is between Animal and Man, which are differentiated by the phenomenon of self-consciousness or self awareness. Self-consciousness is the reflective awareness of one's consciousness and thoughts.

Schumacher realizes that the terms—life, consciousness and self-consciousness—are subject to misinterpretation so he suggests that the differences can best be expressed as an equation which can be written thus:

    'Mineral' = m
    'Plant' = m + x
    'Animal' = m + x + y
    'Man' = m + x + y + z

In his theory, these three factors (x, y and z) represent ontological discontinuities. He argues that the differences can be likened to differences in dimension; and from one perspective it could be argued that only humans have 'real' existence insofar as they possess the three dimensions of life, consciousness and self-consciousness. Schumacher uses this perspective to contrast with the materialistic scientism view, which argues that what is 'real' is inanimate matter; denying the realness of life, consciousness and self-consciousness, despite the fact each individual can verify those phenomena from their own experience.

...

Schumacher points out that there are a number of progressions that take place between the levels. The most striking he believes is the movement from passivity to activity, there is a change in the origination of movement between each level:

    Cause (Mineral kingdom)
    Stimulus (Plant kingdom)
    Motive (Animal kingdom)
    Will (Man)

One consequence of this progression is that each level of being becomes increasingly unpredictable, and it is in this sense that man can be said to have free will.

He notes increasing integration is a consequence of levels of being. A mineral can be subdivided and it remains of the same composition. Plants are more integrated; but sometimes parts of a plant can survive independently of the original plant. Animals are physically integrated; and so an appendage of an animal does not make another animal. However, while animals are highly integrated physically, they are not integrated in their consciousness. Humans, meanwhile are not only physically integrated but have an integrated consciousness; however they are poorly integrated in terms of self-consciousness.

Another interesting progression, for him, is the change in the richness of the world at each level of being. A mineral has no world as such. A plant has some limited awareness of its immediate conditions. An animal, however, has a far more rich and complex world. Finally, humans have the most rich and complicated world of all. "

-- https://en.wikipedia.org/wiki/A_Guide_for_the_Perplexed#Levels_of_being

this sort of thought is a distillation from the old religious idea of the https://en.wikipedia.org/wiki/Great_chain_of_being , which itself is a distillation of an idea of Aristotle (scala naturae, i think). (note the similarity to the science fiction 'toposophic levels' of Orion's Arm)

general dynamics

some concepts from biology, ecology, nonlinear dynamics, cybernetics, complex systems, 'general dynamics'/'general systems'

r/K selection theory

This describes two prototypical classes of reproductive strategy.

One strategy, the 'r' class, is to have a high rate of reproduction with low cost per individual offspring. Examples of 'r' are bacteria, diatoms, insects, grasses, dandelions, "various semelparous cephalopods", small rodents. The opposite strategy, the 'K' strategy, is to have a lower rate of reproduction, but in exchange each individual produced has a higher probability of surviving to adulthood. Examples of 'K' are orchids, elephants, primates, whales, and Arctic terns. The letters are chosen because 'r' stands for 'rate' and K for 'carrying capacity' (the word for capacity starts with a K in German). In short, 'r' is to produce many cheap and low-quality individual and 'K' is to produce a few expensive and high-quality individuals.

'r' traits include "high fecundity, small body size, early maturity onset, short generation time, and the ability to disperse offspring widely." 'K' traits include "large body size, long life expectancy, and the production of fewer offspring, which often require extensive parental care until they mature".

Wikipedia notes that "Although some organisms are identified as primarily r- or K-strategists, the majority of organisms do not follow this pattern. For instance, trees have traits such as longevity and strong competitiveness that characterise them as K-strategists. In reproduction, however, trees typically produce thousands of offspring and disperse them widely, traits characteristic of r-strategists.[13] Similarly, reptiles such as sea turtles display both r- and K-traits: although sea turtles are large organisms with long lifespans (provided they reach adulthood), they produce large numbers of unnurtured offspring."

It is thought that r strategies predominate in environments that are rapidly changing, and K strategies predominate in environments that are close to 'carrying capacity'. "In unstable or unpredictable environments, r-selection predominates as the ability to reproduce quickly is crucial. There is little advantage in adaptations that permit successful competition with other organisms, because the environment is likely to change again." r species "typically exploit less-crowded ecological niches". "r-selected species are occasionally referred to as "opportunistic" whereas K-selected species are described as "equilibrium"."

"In stable or predictable environments, K-selection predominates as the ability to compete successfully for limited resources is crucial and populations of K-selected organisms typically are very constant in number and close to the maximum that the environment can bear (unlike r-selected populations, where population sizes can change much more rapidly)."

Organisms following an r strategy are sometimes referred to as r-strategists or r-selected, as likewise for K.

"The r/K dichotomy can be re-expressed as a continuous spectrum using the economic concept of discounted future returns, with r-selection corresponding to large discount rates and K-selection corresponding to small discount rates."

"These terms, r and K, are drawn from standard ecological algebra as illustrated in the simplified Verhulst model of population dynamics:[9]

    \frac{dN}{dt} = rN \left(1 - \frac{N}{K}\right) "

Ecological succession: "In areas of major ecological disruption or sterilisation, ... Because of their higher reproductive rates and ecological opportunism, primary colonisers typically are r-strategists and they are followed by a succession of increasingly competitive flora and fauna....Eventually a new equilibrium is approached (sometimes referred to as a climax community), with r-strategists gradually being replaced by K-strategists which are more competitive and better adapted to the emerging micro-environmental characteristics of the landscape"

Ecology may now consider r/K selection to be oversimplified? [1]

Links:

• https://en.wikipedia.org/wiki/R/K_selection_theory (quotes above are from here)

neuro

digital signal (action potential; threshold),:

A significant component of the human nervous system is based on binary coding; long-distance transmission of information in our nervous system is primarily accomplished by nerve impulses through axons, which is in the form of 'spikes' (named for their appearance on a graph of voltage vs time), eg at any point in time, a part of an axon can be considered to be either in an 'off' state (no spike, low voltage) or an 'on' state (spike, high voltage). The duration of spikes is relatively brief (hence their characteristic shape for which they are named), that is to say, unlike voltage signals in electronic computers, axons never hold in the 'on' state for an extended period of time; rather, spikes are approximately 'instantaneous', and the information transmitted over an axon over time can be approximated by a list of times at which there were spikes, called a 'spike train'.

Note that it does take an appreciable amount of time for spikes to propagate down axons, so when one axon sends information to multiple synapses (as is typical), the times at which the spike reaches these synapses will be slightly different. This may be important as downstream neurons react differently to the (approximate) coincidence of incoming spikes (eg a neuron may do something special when it receives multiple spikes from different sources at about the same time, as opposed to receiving the same spikes from the same sources at times which are more widely spaced), and in fact may even care about exactly which spikes was received first (see eg https://en.wikipedia.org/wiki/Hebbian_theory, https://en.wikipedia.org/wiki/Spike-timing-dependent_plasticity, http://scholarpedia.org/article/Spike-timing_dependent_plasticity , Polychronization: Computation With Spikes for related discussion).

directional transmission (principle of dynamic polarization), principle of connectional specificity, synapses, axonal transmission delay and synaptic delay,

some synapses are excitatory and some are inhibitory

usually many afferents need to sum, both spatially and temporarily

transmission is mostly chemical via neurotransmitters at synapses, but there is some electrical (gap junctions, which are not directional; also https://en.m.wikipedia.org/wiki/Ephaptic_coupling)

refractory periods

some neurotransmitters and (some of) their receptors: ach ('cholinergic' nicotinic, muscarinic), todo

links:

• http://nba.uth.tmc.edu/neuroscience/m/s1/index.htm

todo: skimmed up to page 46 of "synapses" (looking for important conclusions only, not history). see some pictures on my phone for other stuff i wanted to add notes on.

some parts of the brain and what they might do

neurons and spikes

https://en.wikipedia.org/wiki/Clade

---