Speciation Continued

My reading continues and is going fairly well. I only wish that the authors had chosen a more concise way of saying that sympatric speciation does not seem to be common in nature. 50 pages was a little tedious. I understand the need for specific examples, but the chapter gave far too many.
In summary, there are currently no examples of speciation that are totally accounted for by sympatric speciation. There is simply a lack of evidence at this point.

Speciation

This book is a lot more interesting than the brief intro I got to the concept in ZOO 1114. It’s fairly straightforward so far, talking about concepts and examples.

My best friend wrote a computer program that gives randomized tables on command. This was *very* useful for making my cave mollies table. The female population is randomized, as are the male populations. He can make another randomized table just by refreshing the page. It’s pretty interesting, and saved me a lot of time. I looked over it, and it is as random as I could’ve made it from flipping coins or using a random number table.

Ch. 7 Animal Signals – Final

Signals in primates and other social animals
*Vervet Monkeys: a case studyd
-predator-specific alarm calls (cat, eagle, dangerous snake)
-different “adaptively appropriate responses” for each call: attack snake, run…
-also “minor predator” and “unfamiliar human” calls
-rules of human language stay the same, but words andd meanings change across populations and dialects — same for monkeys.
*How does the ability to signal develop?
-skills required to communicate:
1. ability to produce correct signal (ex: acoustically correct sound)
2. ability to signal in correct circumstances
3. ability to respond correctly to a signal
-in Vervets: production of calls is partially genetic but requires experience to do properly (as do production in correct circumstances and proper responses). No evidence of explicit teaching, but infants do learn by observing adults. Can also learn to respond to certain bird alarm calls – the more frequent the calls, the faster infants learn to respond to them.
*What’s going on in an animal’s head?
-do signals convey info about the external world? Monkeys interpret calls as sounds that represent stuff in the outside world (thus the signals are not just triggering a response that follows behavioral rules)
-do signalers intend to alter behavior of receivers?
1. zero-order intentionality: signaler holds no beliefs or desires (caterpillar)
2. first-order intentionality: signaler holds beliefs, but not beliefs about beliefs of others
3. second-order intentionality: signaler ascribes thoughts and beliefs to receiver — no clear evidence that non-humans can do this
*social reputation + signal honesty
-immediate punishment of dishonesty: reputation is not involved
-direct reputation: B remembers that A lied
-indirect reputation: C sees A lie to B; C doesn’t trust A tomorrow — not yet known if non-humans can do this
-reported reputation: A lies to B; B tells C; C doesn’t trust A tomorrow — common in humans, doubtful that other primates can do this.
-stable system of cost free signals can evolve if individuals interact repeatedly
*group displays: It’s hard to determine the exact significance of group signals. Reinforce group identity / cooperation? Dominance displays? My group is better / bigger / fiercer / prettier than your group?
*Human language
-the ability to learn to talk not aspect of general leraning ability — genetic competence peculiar to language
-protolanguage (Sam apple bite) eventually evolved to the modern form of communication (Sam bit the tasty red apple because she was hungry and cheese was not available for consumption.)

Ch. 6 Animal Signals

Signals during contests:
Why are signals reliable when the contestants prefer different outcomes?
1.) signal is index either of fighting ability or need for contested resource – lying is impossible
2.) signal is handicap: risky to make and too costly for low-quality individual or one not in serious need of resource
3.) contestants have common interest – avoiding escalation, usually.
Badges of status:
Patches of color that influence outcome of contests, though not logically correlated with fighting ability (plumage variation does not always indicate status)
BoS usually used in contests over resources of low value.
“bluffing” mutants are punished – impossible to signal high aggression and retreat at once without cost if opponent also signals high aggression.
Signals of need:
Individual with highest need is more motivated – signals longer. Need varies continuously (sometimes hungry, sometimes not). Bluffing must be punished in some manner.
Punishment of false signals:
Falure of signal to match behavior is punished with aggression. Or, giving the signal requires a minimum cost that a bluffing individual is not ready to pay. Social enforcement of signal honesty – liers are punished with violence. If the cost of punishing a bluffer is lower than the cost of being punished, then a system of cooperation will be more stable.
Protracted contests and varied signals:
If a contest can be settled by a series of relatively cheap actions, why escalate to costly behavior if it’s not necessary?
Escalation in intensity as time wears on in the contest.
Territorial negotiation: continue until neighbor’s display = yours in intensity. Escalate until opponent escalates in response – settle territorial dispute.
Relatively cheap negotiation phase followed by a more costly settlement phase.

This chapter was not as interesting as the previous chapters. There is only one more chapter left in this book.

Finally

Apologies for the long delay; this past week was very unpleasant. See personal blog for details if interested.

Animal Signals Notes

Ch. 3 – Strategic Signals and Minimal Cost Signals

3 main reasons for signal reliability:
1. handicap principle: signal is too costly for signaler of low-quality
2. no gain to signaler by lying even if signal is cost-free Ex: common interest between signaler and receiver – they rank possible outcomes in the same order of preference
3. signal cannot be faked – “index”

Strategic Signaling: cost of given signal is relatively lower for high-quality individuals. Genetic variation for strength of signal and dependence on quality — Handicap Principle
Minimal Cost Signals: Reliability does not depend on cost and could be given by any signaler

-contexts in which this can be an ESS:
1. common interest (can include both related and non-related individuals)
2. dishonest signals are punished
3. signaler and receiver prefer different outcomes, but share an overriding common interest (often avoidance of physical conflict). coordination game: contest solved by unambiguous signaling of asymmetries through indexes
4. repeated interactions between same pair of individuals – reputation

Ch. 4 – Indices of Quality
“Cues rendered honest by anatomical constraint provide receivers with accurate information.”

Indices indicate:
• condition (healthy or starved)
• size
• performance
• parasite infestation (heritable resistance to parasites?)
• ownership of resource (scent marking, calls)

Ch. 5 – Evolution of Signal Form
Ritualization: change of pre-existing cue into a signal

Differences between cues and ritualized signals
1. conspicuousness
2. redundancy: some combination of types of signal (visual + sound, etc)
3. stereotyped behavior
4. alerting components: loud/flashy alert followed by subtler signal

Efficacy – ability of signaler to manipulate receiver. Ritualization sometimes increases efficacy.
Mimicry and cheating work best when they are rare – the signal is usually honest, so the receiver usually benefits from always responding the same way to the signal

Plans

The best laid plans of mice and men often go awry.
Or, in my case, those plans are delayed by illness, job commitments, and a pile of homework.

Updates will return as soon as possible (or as soon as I can without completely foregoing sleep).

Useful Papers?

I’ve been very sick all weekend and still don’t have full mental capacity (I barely managed to order a sandwich for lunch without falling over), so I’m listing titles, authors, and abstracts of papers that may be useful once I’m well again and can figure out what they say:

1. Recent behavioral history modifies coupling between cell activity and Arc gene transcription in hippocampal CA1 neurons
Guzowski JF, Miyashita T, Chawla MK, Sanderson J, Maes LI, Houston FP, Lipa P, McNaughton BL, Worley PF, Barnes CA
Abstract: The ability of neurons to alter their transcriptional programs in response to synaptic input is of fundamental importance to the neuroplastic mechanisms underlying learning and memory. Because of technical limitations of conventional gene detection methods, the current view of activity-dependent neural transcription derives from experiments in which neurons are assumed quiescent until a signaling stimulus is given. The present study was designed to move beyond this static model by examining how earlier episodes of neural activity influence transcription of the immediate-early gene Arc. Using a sensitive FISH method that detects primary transcript at genomic alleles, the proportion of hippocampal CA1 neurons that activate transcription of Arc RNA was constant at approximate to 40% in response to both a single novel exploration session and daily sessions repeated over 9 days. This proportion is similar to the percentage of active neurons defined electrophysiologically. However, this close correspondence was disrupted in rats exposed briefly, but repeatedly, to the same environment within a single day. Arc transcription in CA1 neurons declined dramatically after as few as four 5-min sessions, despite stable electrophysiological activity during all sessions. Additional experiments indicate that the decrement in Arc transcription occurred at the cellular, rather than synaptic level, and was not simply linked to habituation to novelty. Thus, the neural genomic response is governed by recent, but not remote, cell firing history in the behaving animal. This state-dependence of neuronal transcriptional coupling provides a mechanism of metaplasticity and may regulate capacity for synaptic modification in neural networks.

2. Rapid behavioral and genomic responses to social opportunity
Burmeister SS, Jarvis ED, Fernald RD
Abstract: From primates to bees, social status regulates reproduction. In the cichlid fish Astatotilapia (Haplochromis) burtoni, subordinate males have reduced fertility and must become dominant to reproduce. This increase in sexual capacity is orchestrated by neurons in the preoptic area, which enlarge in response to dominance and increase expression of gonadotropin-releasing hormone 1 ( GnRH1), a peptide critical for reproduction. Using a novel behavioral paradigm, we show for the first time that subordinate males can become dominant within minutes of an opportunity to do so, displaying dramatic changes in body coloration and behavior. We also found that social opportunity induced expression of the immediate-early gene egr-1 in the anterior preoptic area, peaking in regions with high densities of GnRH1 neurons, and not in brain regions that express the related peptides GnRH2 and GnRH3. This genomic response did not occur in stable subordinate or stable dominant males even though stable dominants, like ascending males, displayed dominance behaviors. Moreover, egr-1 in the optic tectum and the cerebellum was similarly induced in all experimental groups, showing that egr-1 induction in the anterior preoptic area of ascending males was specific to this brain region. Because egr-1 codes for a transcription factor important in neural plasticity, induction of egr-1 in the anterior preoptic area by social opportunity could be an early trigger in the molecular cascade that culminates in enhanced fertility and other long-term physiological changes associated with dominance.

3. Molecular cloning and effect of c-fos mRNA on pharmacological stimuli in the goldfish brain
Fujikawa Y, Kozono K, Esaka M, Iijima N, Nagamatsu Y, Yoshida M, Uematsu K
Abstract: c-fos is an immediate early gene, and is rapidly and transiently induced in neurons of the central nervous system according to their activities. To investigate neuronal activities in the brain of the goldfish (Carassius auratus), we considered that expression of c-fos mRNA would be an available marker for the neuronal activities. Therefore, we firstly isolated a cDNA clone encoding c-Fos from the goldfish brain by RT-PCR and RACE methods. A full length cDNA of the goldfish c-fos was composed of 1044 bp open reading frame. The amino acid sequence of the goldfish c-Fos was approximately 56-90% identical to those of other teleostean fish c-Fos. Northern blot analysis showed that the expression of c-fos mRNA was rapidly and transiently induced in the brain of the goldfish by the intraperitoneal administration of kainic acid. We also showed that the identification of the c-fos mRNA expression site by in situ hybridization will be able to be used as an anatomical marker for the identification of the activated neuronal region in the goldfish brain.

4. Title: Identification of c-fos related genes and their induction by neural activation in rainbow trout brain
Author(s): Matsuoka I, Fuyuki K, Shoji T, Kurihara K
Abstract: A number of studies have shown that the induction of c-fos gene is an indicator of the responses of cells and tissues to the environmental stimuli. In the present study, using RT-PCR-based strategy, we isolated, rom the brain of the rainbow trout, two partial cDNA clones (RT-fos1 and RT-fos2) that code proteins homologous to c-Fos proteins of higher vertebrates. Sequence analysis of the two clones indicated that the two rainbow trout clones are very similar to each other over the entire cloned region (88% amino acid identity) and showed moderate similarity to c-Fos proteins of higher vertebrates (40% amino acid identity with human c-Fos). Two functionally important domains (i.e. the leucine zipper and zinc finger) are highly conserved among all the vertebrate species analyzed, although the region between the two domains was highly variable between different species. Intraperitoneal administration of kainic acid, a stable agonist of glutamate receptors, transiently induced the mRNAs for both RT-fos1 and RT-fos2 in the rainbow trout brain. These results indicate that the expression pattern of the two clones can be utilized as a suitable anatomical marker for the increased neural activities in salmonid fish brain to investigate the higher order behavior such as the learning and imprinting of odors of the home river.

Search terms: early immediate gene fish
Search results: 38
Problems: FISH technique instead of the animal fish

I will have to continue this search later as my fever is returning.

Endnote

Must be transferred from a master copy in possession of someone at OU. It is not available from IT as far as I can tell. Dr. Lawson in the microbiology department has one.

IACUC

IACUC forms must be filed 1 week prior to scheduled meetings. There’s a meeting on August 14th, but that is in less than a week. The next meeting is listed on the website as October 26 at 11:30-12:30, Sutton Hall Rm # 312. This is both good and bad. I have plenty of time to figure out everything I need to do for the experiment and will be well prepared by then (or else). However, this means I won’t get started on the actual experiment for quite a while… At least I have another semester to work on it. And if all else fails I will still be here in Fall ‘08 to continue if necessary.

Forms here

Animal Signals Ch. 1-2

Chapter 1 gives some background on previous usages of terms, then defines and explains the terms that the authors of this book use consistently through the rest of the text. I was familiar with the majority of the terms, except for the more technical aspects of signaling and a few terms that were different from the first book. (Index, for example, is a signal of something that cannot be faked. I remember the example of a tiger that scratches as high up on a tree as it can reach. The scratching is an index of the tiger’s size.)

Chapter 2 discusses costly signals and whether honest signals are required to have some cost. The authors come to the conclusion that honest signals do not necessarily have to cost the signaler. I dislike math, so I preferred the word summaries of the mathematical models to the math itself.

This book is a much better read than the other. I appreciate the clear and constant definitions used throughout the book.