EP #`13: Awakenings, Oliver Sacks

January 2024

Entry 13 in the Essays Project with CT; this is the seventh book we’ve read by Oliver Sacks. This is the book that, with the help of a documentary and then movie, transformed him into something of a celebrity. It is an account of the experience of ‘awakening’ patients with Parkinson’s induced by Encephalitis Lethargia by administering L-Dopa, their experiences of returning to a sort of normal life, and then their declines due to the follow-on negative effects of L-Dopa.

LS*–The High Sierra: A Love Story, Kim Stanley Robinson

November 2023

The High Sierra: A Love Story, by Kim Stanely Robinson. 2022.

* I was reading this for other reasons, but nevertheless it fits well into my project to read essays that focus on landscape and natural history.

TL;DR: I love this book. But it is not for everyone. On the other hand, it is organized in such a way that readers interested in particular topics — geology, history, etc. – could skip through the book attending to one or a few themes that interest them. It has great pictures, too.

I’m a big fan of KSR, and think it likely that I’ve read everything he’s written, although it is possible that that omits a few early science fiction novels that were retroactively published after he became better known. I like the complex characters he develops, the intensely developed worlds he portrays, and especially his attention to geology, climate, economics, politics, and the role of large institutions – themes that are uncommon in much science fiction. Also unusual is that he sometimes ventures beyond the borders of SF, as with his novel Years of Rice and Salt, and especially with this book, which is multi-threaded work the interweaves memoir, geology, natural history and history.

w/CS: Elixir: A History of Water and Humankind*, Brian Fagan

November 2023…

*Elixir: A History of Water and Humankind, Brian Fagan. Reading with CJS.

Comment after finishing seven chapters:
There is interesting material here, and I am happy to be reading it. However, the writing is not grea: it is difficult to follow if you are really trying to get a deep sense of what is going on.

The same date is sometimes referred to as 4,000 BCE, 6,000 years ago, or a millennia after another event. I can do the math, but pausing to do so drops me out of the flow of the text.
The maps helpfully included in the chapters lack many of the places referred to in the text: Where are the Taurus mountains? Are they the same as the mountains near Cudi Dag (not shown on the map either). Clearly, neither writer nor editors ever tried referring to the associated map…
Places are also referred to with different names: The Lands of Enlil; Southern Mesopotamia; the lands to the south of modern-day Bagdad; the Fertile Crescent refer, I think, to the same area. But it is difficult to be sure.
Often it is unclear what the relationship between sequential examples are — are they supposed to reinforce one another, or complement one another, or are they being presented for some other reason? Sign-posting would be really helpful.

Preface

The three themes of this book are (1) gravity and its fundamental impact on the flow of water; (2) the relationship between ritual and water management; and (3) sustainability. One point the book will take up is the way in which the invention of the mechanical pump transformed the mining and movement of water.

The book takes an anthropological perspective, closely examining the relationships between water technologies and human usage and management practices, and looking at the role rituals play. It looks at both historical examples — even reaching into the deep past where the primary source of information is archeological work — and present day examples. And of course the book addresses the ongoing crisis in water sourcing and distribution, and the question of sustainability.

EP#12: The Mind’s Eye, Oliver Sacks

November-December 2023

Entry 12 in the Essays Project with CT; and this is the sixth book we’ve read by Oliver Sacks. Here we take up the neurological case account essays for which he is best known, after reading his two autobiographies, and other writings ranging from general essays to an account of his travels in Oaxaca. This book, published in 2010, explores cases in which people have lost visual abilities that we all take for granted – not so much blindness (although maybe there will be some essays on that), but rather the consequences of some of the many ways in which the complex and intertwined elements of the visual processing system may be disrupted.

w/CS: Islands of Abandonment: Nature Rebounding in the Post-human Landscape, by Cal Flyn

September 2023

Islands of Abandonment: Nature Rebounding in the Post-human Landscape, by Cal Flynn, 2021.* This book looks at how nature — fungi, plants, animals – are re-colonize landscapes that have been destroyed and abandoned by humans. Examples include massive slag piles, nuclear test grounds, etc. It examines both how primary succession occurs in unpromising circumstances, and how the absence of human presence facilitates re-wilding. In the introduction, the author notes that we are now in the midst of a vast self-directed experiment in re-wilding, driven in part by the concentration of people in cities (and a soon-to-be-decreasing population), and in part by the depletion of non-sustainable natural resources that leave ‘waste lands’ behind.

Post-reading comment: There are three or four chapters in the book that are great, and really align with the aims laid out above. Unfortunately, more of the chapters, particularly as one progresses in the book, are more in the line of what I would call disaster tourism: lyrical descriptions of degraded environments and terrible situations, with little or no mention of how the ecosystem has adapted or not.

* Reading with CJS, fall of 2023

w/CS: Assembling California*, John McPhee

July 2023

* Reading with CJS. Page numbers cited are from Annals of the Former World, a collection of his work of which Assembling California is only one part. The parts of the AC, as described below, are not well-separated in the text; they only appear in the table of contents.

w/RB: An Immense World: : How Animal Senses Reveal the World Around Us, Ed Yong

An Immense World: How Animal Senses Reveal the World Around Us, Ed Yong, 2022.

Overall, a good book. Yong writes well, and sometimes has very nice turns of phrase, though I’d say his gift is more for clarity and content than lyricism. The downsides of the book — small ones but nevertheless there — is that he often doesn’t go as deeply into the mechanisms and neurophysiology of sensing as I would like. It is also the case that one gets a bit of whiplash from looking first at this organism, and then at that, and then at that — but I don’t see how that could have been avoided in this sort of book.

To summarize briefly and incompletely, here are some of the points I found most interesting:

What we think of as a single sense (e.g., vision) can be quite complex. All of the following can be separate: distinguishing light from dark areas; color vision (and bi- tri- and tetra-achromatism); ability to see polarized and/or UC and/or infrared light; and more.
Also, the same sense can be configured and deployed in different ways: the shape of an organism’s visual field is tightly bound with its role in the food web; an organism may have one, two or multiple eyes, and may be able to move them independently; and so on.
Some senses seem easy to evolve, in that they have been independently evolved at many different points in time. And then lost, and then re-evolved.

April 2023 – February 2024

Introduction

The book begins with a fanciful description of a room with different creatures in it, including a human, a robin, an elephant, a spider, and so on. It uses this to make the point that the different creatures, although all in the same room, have radically different impressions of the room and its occupants. What is evident to one is invisible to another. An organism’s very particular view of its environment – is referred to as its umveldt, coined by Jacob Uexkull in 1909.

w/CS: The Ends of the World, Peter Brannon

The Ends of the World: Volcanic Apocalypses, Lethal Oceans, and our Quest to Understand Earth’s Past Mass Extinctions. Peter Brannon. 2017

April – June 2023

Summary of Periods and Mass Extinctions

Edicarian: 635-538. First appearance of wide-spread multi-cellular organisms in ocean: Soft-bodied microbial organisms forming mats and other structures, and free-floating filter feeders.
End-Edicarian extinction: ~448. 86% species went extinct.* Possibly due to advent of burrowing organisms that disrupted largely sessile ecosystem. Not an official mass extinction because of a very incomplete fossil record.
Cambrian: 538-485. Warm shallow seas flank margins of several continental remnants of the breakup of the supercontinent Pannotia. In ocean there is the advent of hard-bodied complex organisms, and subsequent explosion of diversity into all phyla known today. The land bare except for microbial crust; arthropods and mollusks begin to adapt to life on land towards the end of this period.
Ordovician: 485 – 433. High CO2 levels and continents inundated with vast shallow seas jammed with life: brachiopods; trilobites; cephalopods; eurypterids; grapholites; and jawless fish. Many isolated continents and islands, with continents at south pole and a global sea occupying most of the northern hemisphere. First spores of land plants (fungi and simple plants) at 467Ma, with their spread possibly releasing phosphorous into the ocean stimulating algal blooms and CO2 sequestration.
End-Ordovician extinction:~345 Ma. 75% species went extinct.* Major ice age, likely precipitated by biogenic CO2 depletion, followed by a whip-lash of warming.
Silurian: 443-419. Gondwanaland and island chains provide diversity of environments; in the ocean early fish diversify into jawed and bony fish. Terrestrial life expands in the Silurian-Devonian Terrestrial Revolution: vascular plants emerge from more primitive land plants, and three groups of arthropods (myriapods, arachnids and hexapods) became fully terrestrialized.
Devonian: 419-359. Gondwana supercontinent in the south, Siberia to the north, and Laurussia to the east. Free-sporing vascular plants form extensive forests (Archaeopteris); by the middle of the Devonian several groups have evolved leaves and true roots; by the end the first seed-bearing plants appear.
Late-Devonian extinction event: ~250 Ma. 96% species went extinct.* Two major extinction pulses, and many smaller pulses. One theory is that it is due to the release of nutrients by the punctuated spread of land plants as they developed vascular systems with leaves and roots, and seeds.
Carboniferous: 359-299. Age of amphibians — also first appearance of amniotes from which both reptiles and mammals came. Vast rainforests covered the land, and insects diversified. The latter part of the Carboniferous experienced glaciations, low sea level, and mountain building as the continents collided to form Pangaea. A minor marine and terrestrial extinction event, the Carboniferous rainforest collapse, occurred at the end of the period, caused by climate change
Permian: 299-251. On land: The Carboniferous rainforest collapse left behind vast regions of desert in the continental interior. Amniotes, which could better cope with the conditions, diversified into the synapsids (the ancestors of mammals which came to dominate the Permian) and the sauropsids (reptiles). . In the ocean fish diversify with placoderms dominating almost every known aquatic environment, alongside coeleocanths, with sharks and bony fishes on the sidelines.
End-Permian extinction: 251.9 Ma. 80% of species went extinct.* The Siberian Traps were created at 252 Ma and also interacted with the Tunguska sedimentary basin filled with carbonates, shale, coal and salt in layers up to 12 Km thick; it is the worlds largest coal basin. When the magma intersected the basin, it caught fire, detonated in multiple places, and released vast about of CO2 and methane, on top of the CO2 produced by the eruption contributing to global warming and ocean acidification and anoxia. Other chemicals produced by the incineration of the Tunguska basin contents may have destroyed the ozone layer.
Triassic: 252-201. Brannen argues for a long 5 – 10 million year recovery, but that is disputed. The ancestors of crodcodiles dominated the Triassic; ancestors of dinosaurs and first true mammals appear, but were not dominant. The global climate during the Triassic was mostly hot and dry. Pangea had deserts spanning much of its interior until ita began to gradually rift into Laurasia and Gondwana to the south. In line with this the climate shifted from hot and dry to more humid, with a massive rainfall event called the Carnian Pluvial Event that lasted a million years.
End Triassic Extinction: 200 Ma. 80% of species went extinct.* Volcanism from the rifting of Pangea produced flood basalt that covered more than 4 million square miles. The CO2 concentration doubled or tripled, raising the already warm temperatures by at least 3 ° C. The final extinction pulse was fast: on the order of 20,000 years.
Jurassic: 201.4 – 145. Gondwana begins to rift. Climate warm and humid.
Cretaceous: 145 – 66. Gondwana completes rifting and by the end of the period today’s continents are recognizable, but with shallow inland seas in North America and Africa and between Greenland and Norway.
End Cretaceous Extinction: xxx. 76% of species went extinct.* Most likely some combination of the eruption of the Siberian Traps and the Chixtulub impact lead to global warming and an extended period of darkness. Almost all large animals eliminated, including all dinosaurs excerpt ancestors of birds.

Percent of species that went extinct, for any one event, vary considerably among sources. These numbers are better read as an indicator of relative severity.

w/CS: The Tangled Tree: A Radical New History of Life, David Quammen

January – April 2023

The Tangled Tree: A Radical New History of Life, David Quammen, 2018. These are my chapter by chapter notes. Besides having very good reviews and being by a well-regarded author, this book got a (rare) very high rating from Reid Priedhorsky…

Read this with CS.

w/KC: Metaphors We Live By, Lakoff and Johnson, 1980

January 2023

The Book: Metaphors We Live By, George Lakoff and Mark Johnson, 1980

Prelude

Written in 1980, this book challenged what was then the conventional view of metaphor – in psychology, linguistics and philosophy – as a sort of minor, poetical flourish that had little to no role in the how people understand language. In sharp contrast, MWLB argued metaphor is central to not only the way humans understand language, but how they conceptualize and experience the world. The suggest that most metaphor is systematic, in that there are root metaphors which structure the way abstract topics are conceptualized. L&J distinguish among three types of metaphoriic systems: Structural (ARGUMENT IS WAR); Orientational (MORE IS UP); and Ontological (IDEAS ARE OBJECTS). They also not that metonymy, while it is referential rather than metaphorical, is systematic in the same way metaphor is.

w/CS: Alien Oceans: : The Search for Life in the Depths of Space, Kevin Peter Hand

25 October 2022 and on…

CS and I are reading Alien Oceans: The Search for Life in the Depths of Space, by Kevin Peter Hand. These are my chapter by chapter notes. We are now through chapter 7, and are enjoying it. It does not assume much science background, and thus spends a lot of time explaining things that we are familiar with (e.g. why water’s hydrogen bonds cause water ice to be lower density than liquid water). But it does a very good job of it, and those with background can skim; this would be a great book for a child or teen interested in science.

w/KC: Entangled Life: How Fungi Make Our Worlds, Change Our Minds & Shape Our Futures, Merlin Sheldrake

October – November 2022

These are chapter-by-chapter notes (with occasional quotes) on Entangled Life: How Fungi Make our Worlds, Change our Minds, and Shape our Futures, by M. Sheldrake. I’m reading this book with KC, a chapter or two at a time, and adding notes for each chapter as I go. Having now finished it, my one line review is that it has some fascinating stuff in it, but it is a lot more focused on cool stuff than on giving a detailed account of the science.

w/CS: Otherlands: A Journey Through Earth’s Extinct Worlds, Thomas Halliday- Introduction

Tuesday 15 March 2022

LATER: This is the best science book I have ever read; I have a 20+ page document of notes on both the content and the lyrical writing. I regret that I had not systematically started keeping notes in this blog at the point we were reading this.

This morning CS and I meet to begin our discussion of the book Otherlands, by Thomas Halliday. Halliday is a paleontologist and evolutionary biologist who investigates long-term patterns in the fossil record; he appears to be quite young, but has already won a raft of awards for his scientific work as well as one or two awards for his writing. A riffle through the book leaves me with high expectations. I note with approval that it has about fifty pages of notes, all pointing to various scholarly articles and books. The front matter includes an abbreviated chart of geolgical eras (mostly the Phanerozoic eon, presumably indicating the time-span covered in the book); I do like it that the book works backward in time rather than oldest first.

Ant Encounters*, Deborah Gordon

July 2011

* Ant Encounters: Interaction Networks and Colony Behavior, Deborah, Gordon

Chapter 1: The Ant Colony as a Complex System

(1) Our ideas about ants over history have mirrored political fashions and fixations.

(2) The behavior of ant colonies is guided by a dynamic network of interactions.

In 19th C colonial expansion put Europeans in contact with stunning biological diversity of the tropics
Choice of experimental systems (sea urchins, frogs) affects theoretical stance
Our thinking about ants and how they do what they do has tended to mirror current political fashions and fixations
An ants moment to moment response depends on what it is doing and its environment; a colony’s response depends on what happened last week.
Colonies behaviors change over years…
There are always dense webs of contingency in systems of interacting parts
This book presents a single idea about ants: the behavior of ant colonies arises from dynamical networks of interaction . … “A colony’s behavior is guided by a pulsing, shifting web of interactions, in which the pattern of the interactions is more important than the content.”

Chapter 2: Colony Organization

(1) Task allocation: ants can switch tasks, although some roles are sinks. Young workers tend to stay inside the nest, and the transition to roles that take them outside.
(2) Ants make moment to moment decisions about whether to engage in a task or do nothing. And ants don’t have to do things perfectly… just enough to (collectively) get the job done.

We know little about ants and their behavior. They exhibit an astonishing diversity of behavior, and individual exceptions to how even well-studied ants are expected to behave is not uncommon.

“Task Allocation” rather than “Division of Labor,” to emphasize that ant colonies shift their behavior in response to a changing world.
“Even the most elegant argument about what ought to happen does not demonstrate that it does happen.” p. 26
Ants switch tasks if more ants are needed to perform a particular task. However, not all task-to-task transitions are possible. In particular, once a worker has become a forager, it does not switch back to other tasks.
We don’t know much about how ants manage to perform tasks. “It’s important to remember that whatever the ant is doing, it’s not rocket science.” An ant’s performance doesn’t have to be perfect. Instead, enough ants have to perform well enough to get the job done.
How an ant’s task changes with age is extremely variable. However, a general pattern is that younger workers stay inside the nest doing brood care and nest maintenance and move outside of the next when they are older.
Some researchers suggests that as an ant gets older it responds to more stimuli and becomes involved in a greater variety of tasks.
Factors that result in task shifts: (1) the spatial dynamic (what is near to hand); (ii) recent history of the colony’s needs; (iii) current demands of the colony and its environment; (iv) individual differences — some ants are consistently more active than others.
As well as switching tasks, ants make moment to moment decisions about whether to actively engage in a task. When the numbers of workers doing nest maintenance increase, the number of workers foraging decrease — even though foragers themselves are not shifting to maintenance (since foragers don’t shift).
? Why is foraging a sink? Why don’t foragers shift?

Chapter 3: Interaction Networks

(1) Colonies perform a standard sequence of tasks each day. Colonies behavior and responses to disturbances change over time.
(2) Ants interact via antennae touching and sensing cuticular hydrocarbons, and the rate at which they have interactions is crucial. (e.g., foraging is triggered by foragers returning with food at a rate >= 1/10 seconds)
(3) “Differences among species in terms of the speed and intensity of the colony’s reaction come from differences in the rate at which the network is ticking, how often the ants interact, and how quickly and how much they respond. All of the variation among species in interaction networks begins with differences in the shape of the paths that ants use to move around.”
(4) How quickly a group of ants can find something and how quickly information about it spreads through the colony are both enhanced by increased colony size and by straighter paths.… “Adjusting path shape to density [increasing convolutions with density] makes Argentine ants more effective searchers.”
(5) Some ants cluster together when their density is low, but actively avoid one another when density is higher. … As density decreased, ants tended to stick to the boundaries of an area, which is a good strategy for increasing interaction since the boundaries of an area increase linearly whereas the area increases geometrically

Older larger colonies are more stable than young small ones
In a particular ant species, colonies perform a standard sequence of tasks each day. Older colonies respond to disturbances in much the same way each time. A colony’s behavior transforms in predictable ways as it grows older and larger. One colony’s relations with its neighbors look much like another’s.
Task partitioning is the name for a series of tasks that accomplish a goal. For example, foraging, processing food, and transporting it to larva produce the flow of food into the colony.
When ants interact by touching antennae, one ant perceives the cuticular hydrocarbons of another. These are greasy fatty acids that are spread over the hard outer surfaces of an ants body by grooming. …Changes in the cuticular hydrocarbons of an ant triggered by chance events — e.g., when some ants are fed a particular species of cockroaches — can lead to interaction changes.
Foraging and its control by interaction networks. Colony activity begins in the early morning — probably stimulated by the sun striking the earth and warming the ground — when patrollers leave the nest. They lay short trails that show foragers which direction in which to forage, and foragers only go out when patrollers return. (This is ‘wise’ as the failure of patrollers to return may signal a problem.) Once foraging begins, the number of ants out foraging at any given time is regulated by rate of interactions with foragers returning to the nest with food. A change in the rate of forager return alters the rate at which foragers go out very quickly — within about two minutes. This response rate may be determined by the length of an ant’s memory, which is about 10 seconds.
Other cases in which interaction networks control activities are nest choice, midden work, and trail laying.
Interaction rhythms produce colony behavior as a result of the relation of two rates: the rate at which interactions occur and the rate at which ants respond to them, the latter which depends on the ant’s ‘memory.’
Harvester ants appear to be able to remember location from one day to another, in that they will return to the same area to forage if not provided with other cues by patrollers. Species seem to differ in how long they can remember things, with some ants showing memories that last for days (of the colony’s smell) and others showing an apparent memory in ‘old’ ants that can last over the winter.
There are some ants that appear to be much more active than others — about 10% of ants make many trips, while the rest make only a few. But if you take away that most active set of ants, the next day there will be another 10% of highly active ants. (???If you don’t take them away, will the same or different ants be most active the next day???)
“Differences among species in terms of the speed and intensity of the colony’s reaction come from differences in the rate at which the network is ticking, how often the ants interact, and how quickly and how much they respond. All of the variation among species in interaction networks begins with differences in the shape of the paths that ants use to move around.”
In general, if an ant reacts to its rate of encounter by changing the way that it moves, then each encounter will change the probability of future encounters.
How quickly a group of ants can find something and how quickly information about it spreads through the colony are both enhanced by increased colony size and by straighter paths. These two effects interact. Smaller groups must use straighter paths to get the same result as larger groups. … “Adjusting path shape to density [increasing convolutions with density] makes Argentine ants more effective searchers.” [[Another issue is the distribution of what is being searched for — if the distribution is not random (e.g., seeds scattered in a circle around a plant) — then different search algorithms may be called for.]]
Some ants cluster together when their density is low, but actively avoid one another when density is higher. These particular ants can see about an ant-length in front of them, and so can take evasive action. As density decreased, ants tended to stick to the boundaries of an area, which is a good strategy for increasing interaction since the boundaries of an area increase linearly as the sum of the lengths, but its area increase geometrically. In general, when contract rate is random, and each ant may contact any of the others, interaction rate changes as the square of the number of ants, so small changes in density can have large effects on contact rates. So it makes sense to be able to modulate contact rate as a function of density.

Chapter 4: Colony Size

(1) 90% of colonies die before they are 1; if the reach 2 years old, it is almost certain they will live 20-25 years.
(2) Colony behavior changes with the age of the colony. Older colonies
(i) devote fewer ants to foraging,
(ii) avoid foraging overlap with neighboring colonies
(iii) respond to disturbances consistently,
(iv) more readily return to homeostasis,
(v) are more likely to detect events, and
(vi) develop larger and more complex nest structures.
(3) Ants not foraging (or doing other tasks) just wait

In Harvester ants, about 90% of colonies die before they are a year old. If they reach two years old it is almost certain that they will live 20 to 25 years. One reason that young colonies may be prone to death is that there may not be enough ants to maintain functioning interaction networks. An ant might get stranded in a location where the is no other ant to meet, and so it will not do anything.
Colony behavior changes with the age of the colony. Younger colonies devote a higher proportion of ants to foraging than older colonies.
As a colony grows, if ants are not foraging, what are they doing? Surprisingly, the answer seems to be that they are doing nothing. This might be useful for any of a number of reasons. Perhaps they are a reserve (though this has not been observed in 25 years of observations. Perhaps they are a mechanism for food storage. Perhaps they provide a buffer that dampens increases in the interaction rate as the colony grows.
Just as younger colonies devote a higher proportion of ants to foraging, it is also the case that in younger colonies ants switch tasks more readily (is foraging still a sink?); in older colonies, an ant tends to do the same task from day to day unless there is a drastic change in the environment. Not only is task allocation more consistent in older colonies, but when perturbed older colonies tend to respond the same way time after time (within a colony, not between colonies) where younger colonies respond differently each time. Older colonies are also more homeostatic, and tend to return to base conditions after each perturbation
The larger a colony, the more likely it is that if something changes in the environment an ant will detect it
As Harvester ant colonies age, the structure of the nests become not just larger but more complex.
It is interesting to speculate about how very large colonies — of millions of ants — are organized to support interaction among groups and subgroups. One way to deal with this is if the response of an individual in a smaller group requires multiple interactions with ants in a larger group to trigger it.

Chapter 5: Relations with Neighbors

How colonies interact with their neighbors

competition for food source / resource
avoiding overlap while foraging
sharing nests
inhabiting abandoned nests of neighbors
using pherome trails
Avoiding overlap with neighbors seems to be an important function of the patrolling system. It appears that an encounter with a neighbor makes a patroller less likely to reinforce a foraging direction. … Each patroller that meets a neighbor’s patroller avoids returning directly to the nest. Coming back to the nest from another side, it doesn’t put down its chemical secretion in the direction that led to the encounter with the neighbor. Meanwhile, other patrollers that went in other directions and did not meet the neibhbor’s patrollers retun to the nest and do put down the secretion that leads foragers back the way they came. This is sufficient, most of the time, to lead foragers away from the site of the encounter…
However, it is only mature colonies, older than 5 and at their stable size, that avoid foraging towards the place they met a neighbor the previous day.
There is less hostility between colonies founded by closely related queens than those founded by unrelated queens. [cuticular hydrocarbons]
Just as ants within a colony use interaction rate as a cue to the numbers of nestmates performing a task, or finding a nest or food source, so in interaction sbetween colonies, and can use interaction rate o assess the numbers of ants from another colony they are dealing with. The rate at which ants of one colony meet ants of the other depends on the relative sizes fo the two colonies — that is, the ration of numbers of workers in one colony to numbers in another.
colonies sometimes move into the nests of dead neighbors
— ??? I wonder if this changes the behavior of the colony — to what extent does the architecture of the nest affect the ‘processing’? Could or have researchers studies nest structure? It would be interested to apply computer aided tomography to deciphering and studying nest architecture. ??? —
In conflicts between colonies, numbers matter much more than size. In fact, smallness may be an advantage because a colony with access to the same amount of resource can produce larger numbers of smaller ants.
The argentine ants … were less aggressive, and moree likely to avoid interaction with the other species when their colonies were small, but plunged into all-out conflict when there were 1,0000 workers or more.
These conflicts can go on for years…
A colony o fone speices may use the interaction network of the other — e.g., the pheromone trails.
Dominance hierarchies vary according to conditions…
There is no single characteristic that makes invasive ants successful. Instead, their success arises from the local details of their network of ecological relations with other species.
The argentine ant forms supercolonies of genetically related colonies. …In the winter a colony aggregates in one or a few large nests, often at the base of shrubs…. in the spring the ants move out into distinct nests connected by trails… by the end of the summer the colony is at its most dispersed, spanning about 200 meters, its many small nests connected by trails.
How neighboring ants interact with each other determines how they get the resources they need to survive. Over time, these interactions will produce the spacing of colonies on the landscape — for example, if two colonies can’t share a tree, eventually there will only be one in each tree. Behavioral interactions create the spacing of colonies, which in turn influences the availability of resources and thus colony growth, which both feed back to influence the frequency and outcome of behavioral interactions.

Chapter 6: Ant Evolution

Ants evolved from wasps about 130 million years ago. About 90 million years ago they began to diversify, and it is clear that diversity in ants is closely related to the evolution of diversity in plants. A burst of diversity in ant species occurred at the same time as the origin and radiation of the flowering plants. After the K-T boundary, flowering plants increased in diversity, scale insects appeared, and ants evolved to take advantage of scale insects.
Plant-ant mutualisms. What is most remarkable about these examples is that the ants behavior draws on very precise and intimate use of the plant’s physiology.
Discussion of reproduction and the evolution of worker sterility.

Chapter 7: Modeling Ant Interaction

Any model of ant interaction has to have at least two levels. The first specifies how the workers interact within the colony to regulate the acquisition, processing, and distribution of resources [behavior]. The second specifies how the internal processes of the colony connect to the colony’s environment [ecology]. That is, how the colony’s interactions with the rest of the world determine its grownth and reproduction, and how this changes the colony’s environment, which in turn changes its interactions and feeds back on its growth and reproduction.
How do decentralized systems combine variable input and imprecise response, yet manage to have the system respond correctly enough of the time that it can function?
When you watch real ants, they don’t look like they do on TV. You see a lot of bmbling around, a few ants going the wrong way, ants pulling an object in different directions. … The achievements of colonies do not arise from the skill and determination of individual ants. … The colony isn’t like clockwork, but it is ticking.
What is most amazing about ants is that such variable, noisy processes create a system that can accomplish so much. The system is turbulent in every way. The experience of each ant is variable, only loosely tuned to the state of the world, because the rate at which each ant meets others depends on so many small contingencies in how the nats happen to move around. The reaction of each ant to the pattern of encounters it experiences is imprecise, because ants don’t count very carefully and because an ant’s respond to the same experience will be different from one time to the next.

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