Evolution Of Body Plans (animal behaviour mainly) Flashcards
1
Q
What is Synapomorphy?
A
- a shared derived trait (often structural).
- basis for phylogenetics
»> but Synapomorphy can be a result of convergent evolution so does not necessarily reflect evolutionary relationship.
> synapomorphies can be lost during evolutions. Also superficially similar traits can arise independently.
2
Q
What are some traits that support monophyly of animals
A
Multi-cellular, developing from single-called zygote, heterotrophic, contractile musscles, gene sequences e.g RNA, Hox gene function, similar cell junctions, extracellular matrix.
3
Q
What does the question ‘are animals monophyletic mean’?
A
- do they have common ancestors
4
Q
What are animal (metazoan) traits?
A
- Multicellullar
- Development from single-called zygote to multicellular adult
- Heterotrophic, food normally ingested
- most animals move using specialised contractile muscle tissue.
- gene sequences e.g. Ribosome all RNA
- Similarites in Hox gene function
- UNique cell junctions
- Common extra cellar matrix.
5
Q
What are opisthkonts?
A
Organisms in whcih the flagellum, if present is posterior, as in animal sperm - includes fungi, choanoflagellates and animals.
6
Q
In Chanoflagellates what surrounds the flagellum?
A
- collar of actin-filled micro villi surrounding a flagellum- extremely similar in fine structure to some of the simplest animals like sponges.
7
Q
Expalin the thoughts behind multicellular Chanoflagellates and the rise of metazoa
A
An ancestral form, closely related to Chanoflagellates became colonial, with some cell types becoming specialised for different purposes- movement, reporduction etc.
- co-ordination between cells by regualtory molecules that coordinated differntiation and migration of cells in the developing embryo. I.e. Progression to larger metazoan animals.
8
Q
what are some key features of Placoza?
A
- Basal group of the simplest animals - 1mm diameter
- Marine, just a few species described. Multicellular but no regular outline
- flattened and single called like amoeba
- body consists of a simple epithelium enclosing a loose sherbet of stella the cells resembling mesenchyme of some more advanced animals.
- Epithelial cells bear flagella and use it to help creep along the sea floor.
9
Q
What are the key features of Profera? (Sponges)
A
- have some specialised cells but lack cell layers and true organs. Some have exoskeleton made of silicon or calcium carbonate.
- lack clear symmetry
- mostly filter feeders using choanocytes cells to capture food particles and create currents.
- sessile almost exclusively marine
- Almost all sponges are marine. All are sessile and usually grown on hard structures. Usually no clear symmetry in growth form.
- Reproduce- normally hermaphroditic but do not self fertilise.
- spree carried on water currents
- During early embryology, radial cleavage- zygote divides in an even pattern- ancestral condition.
- Diplobastic: 2 cells layers echo and endoderm separated by gelatinous acellular mesoglea form during early embryonic development then differntiation to organs.
- radial symmetry of the body
10
Q
What does Diplobastic mean?
A
- 2 cell layers
Ectoderm and endoderm
11
Q
In what at the blastula stage does the embryonic blasts pore brcome the mouth?
A
- protostomes
12
Q
What at the blastula stage does the blastopore form the anus and the mouth arise from a second pore?
A
- Deuterostomes
13
Q
what is spiral cleavage?
A
- cell division takes place asymmetrically; left and righ are cleaved differently
14
Q
What is radial cleavage?
A
First division takes place at right angles to one another
15
Q
What does it mean I’d an organism is acolomate?
A
- ## Lacking a coelom; the space between gut and muscular body wall filled by mesenchyme cells.
16
Q
What does it mean if an organism ispseudocoelomate?
A
- lacking a true coelom, but has a pseudo oil only enclosed by muscles on the outside. The fluid can protectors as and act as hydrostatic skeleton.
17
Q
What does it mean if an organism is coelomate?
A
- it posses a trye coelom, a body cavity that develops in the mesoderm- lined with a muscular layer, surrounding the internal orgnans, plus outside muscle layer. The fluid can protect organs and act as a hydrostatic skeleton.
18
Q
What is animal behaviour?
A
An animals behaviour is what it does and how it does it, usually in response to stimuli in its environment.
- it is diverse
- can be as characteristic of a species as anatomy and physiology is
- but also there is individual variation learning and even culture.
19
Q
What are the purposes of studying animal behaviour?
A
- welfare
- conservation
- helps us to understand human behaviour
- critical role in evolution and biological adaptations .
20
Q
What is behaviour the product of?
A
- the product of natural selection on phenotypes & indirectly on the genotypes that code for them.
21
Q
Hence summarise what is an animals repertoire of behaviour?
A
- set of adaptations that equip it for survival in a particular environment.
22
Q
What are Tinbergen’s 4 whys?
A
- Causation- proximate factors initiating the behaviour
- Development- the relative roles of genetics & learning in expression of the behaviour
- Evolution - how the behaviour evolved from ancestral phenotypes
- Function - how does the behaviour contribute to the survival of the organism, what are the ‘ultimate’ factors involved.
23
Q
What is comparative psychology?
A
- studies of proximate causation
>mechanisms underlying a behaviour: genetic, developmental, nervous, homronal
> internal or environmental stimuli
> development of behaviour: learning, cognition & intelligence
> often lab based
24
Q
What is ethology & behavioural ecology?
A
- Studies of ultimate causation
> the evolution of behaviour in relation to ecology
> Combines ideas from animal behaviour, ecology and evolution
> selection pressures imposed by the animals environment
> what is the selective advantage of a behaviour under particular ecological conditions?
> field and lab studies
> cost-benefit analysis
25
What is an animals behaviour repertpoire?
- a set of adaptions that equip it for survival in a particular environment
26
What is the adaptive value?
- depends on relative costs and benefits of the behaviour to the individuals environment
27
how can inherited behaviour be modified?
- by experience
28
Why do organisms need to communicate?
- interactions with hetero-specifics & conspcifics
- need to get together to mate
Social interaction
- require some form of directed signal: often specialised behaviours, chemicals, markings or morphological attributes that appear specifically designed for the purpose.
29
How is the sender?
- the individual that transmits signals (actor)
30
Who is the receiver?
- Individual whose probability of behaving in a particular way is altered by the signal (reactor)
31
What is a display?
A signal involving behaviour patterns adapted to function as a social signal
32
What is a channel?
Medium through which signal is transmitted (visual or vocal channels)
33
What is the context?
Setting through which the signal is transmitted & received
34
what is 'noise'?
- background activity in the channel which is irrelevant to the signal being transmitted.
35
What is 'true' communication?
- where the value of information for receiver and sender is positive.
36
What is manipulation?
- when the value of the information for the receiver is zero or negative but for the sender is positive
37
What is eavesdropping/ exploitation?
- when the value of the information for the receiver is positive but sender is zero or negative.
38
What is ignoring or spite?
- where the value of information is zero or negative for the sender and receiver and
39
What is a discrete signal?
- Digital (all or none, on or off)
40
What is a graded signal?
- analog (intensity varies in proportion to stimulus strength)
41
What is a afferential signal?
Communicate information about the sender itself
42
What is a referential signal?
- communicate information about an entity that is external to the communicating individual
43
What are the 4 ways to increase signal info content?
- Composite signal
- Syntax
- Context
- Metacommunication
44
What is the message?
What the signal encodes about the sender
45
What is the meaning
What the receiver construes from the signal, meaning can vary greatly between receipients
46
How can the risks of eavesdropping be reduced?
- signals difficult for eavesdroppers to detect or orate
- signals selectively unavailable to predators e.g colour and grain size.
- direct signals to specific individuals
47
What are audience effects?
- presence or absence of particular onlookers can make behaviours more or less likely according to who the onlookers are.
48
What can the evolution of signals depend upon?
- 'machinery' available to the individual
- evolutionary history of the animals involved
- the environment through which signalling is to occur
- the interests of signaller and receiver (don't always coincide)
49
Evolution of signals can be influenced by receiver-bias ('machinery'). How?
- whcih behaviours act as cues & becomes signals may depend upon sensory biases of the receiver.
- if perceptual organs of the receiver have undergone selection for other functions
> e.g. Insect feeds preferentially on yellow flowers
- yellow will be used in mating displays
50
What makes a 'good' useful signal?
- how well suited a signal is to being detected in the receivers environment
51
What are sensory channels of communication?
The physical form used to transmit signlal(s) from sender to receiver
52
What does the channel selected depend on?
- on the species life history
| - inter-specific variation
53
What is the potential issue with sound degradation?
- degraded signals may be confused with other signals or sounds or simply ignored (message vs meaning).
> worse for high-frequency sounds
> echoes can interfere with rapidly repeated signal elements e.g. Trills in some birds songs.
54
What strategies reduce degradation?
- In forests - low frequency and avoid trills unless notes widely spaced.
- in open terrain- trills favoured- repeated elements can be detected during brief periods of good transmission.
55
What makes a 'good' useful signal?
The following are key requirements for signal reception:
- Detectability
- Discriminability
- Memorability
- Specific & unambiguous
56
What is ritualisation?
- evolutionary process in which signals become stereotyped.
| - reduces ambiguity of signals
57
What is antithesis?
- signals conveying opposite messages often have opposite forms
58
What is the basic evolutionary process of displays?
1. Sender sends behavioural/physiological/morphological cue.
2. Receiver perceives cue
3. Receiver relates cue to motivation/ condition of sender
4. Receiver decision rule (own benefit)
5. Receiver responds
6. Sender - if response is beneficial refines the cue and performs display. Aka start of cycle again.
59
What behaviours did displays evolve from?
- Intention movements
E.g. Teeth baring as threat.
- displacement activities
Occur in conflict situations when animal is undecided as to appropriate response to a stimulus
E.g. Many animals use urine to mark territory
- Behaviour linked to physiolociacl change
E.g. Threat display of many fish involves exaggerated Gill raising; evolved from a morphological/physiological cue:
Fight leads to metabolic rate of O2 intake and therefore more rapid and wider Gill opening.
- Thermoregulatory behaviours
E.g. Hair errection
- Food exchange- comparisons of closely related species.
Courtship in pheasants and relatives:
Food calling = original or primitive behaviour
Evolves so that although food is no longer there, female is attracted to a location on ground by display of male.
- Elaboration of functional behaviours
E.g. Preening during courtship- mandarin ducks
60
What are some typical inter-specific signals?
- 'flash' behaviour
- warning colours
- distracting patterns
- attention-grabbing actions
> playing dead
> alarm signals
- co-evolution of flowers with their insect pollinators
61
What are the 4 types of spacing signals in primates?
1. Distance increasing signals (usually between groups)
2. Distance-maintaining signals - home range spacing
3. Distance-reducing signals- keep group members in touch
4. Proximity- maintaining signals e.g. During social grooming within groups
62
Whats the point of species recognition?
- avoids infertile makings between members of closely related species.
63
what species show
Deme recognition?
Class recognition?
Neighbour recognition?
Kin recognition (differential responses to close relatives)
Individual recognition (maintain social associations)
- White-crowned sparrows
- social insects
- European robin
64
What is the purpose of an Intrapleural-specific alarm?
Alerts group members to danger e.g. Vervet monkeys
| I.e. Semantic: different signals for different dangers = referential communication
65
How can communication aid in finding food?
- an advantage of group living = increased foraging efficiency
- signals to aid in exploration/ acquisition of food
BUT could lead to selfish motivation
- Information centres: information gained by observing successful foragers feedin their offspring (eavesdropping).
66
What typical behaviours constitute giving and soliciting care?
- Begging & offering of food between parent and offspring or among other relatives
- Distress calls by young
- soliciting play
67
What is aggression?
- any activity directed towards the discomfiture of another individual
> this attempts to exclude play-fighting
68
What is agonistic behaviour?
- behaviour patterns used during conflict with a con specific
- excludes play-fighting & predatory behaviour
69
What are 4 potential causes of conflict?
- limited resources
- Heterogeneous environment
- Patchy resources
- Aggregations of individuals
70
How can conflicts be resolved use example of blue tit
- only 1% of agonistic contests involve physical fights
- 2 birds of same sex >> ritualised visual displays
- the displays provide information I.e. The participants decide whether to quit or continue and fight
71
Why are physical fights rare?
Potential high cost (energy expenditure & risk of injury)
Selection favours evolution of conflict resolution mechanisms that avoid it.
Most conflict is resolved by displays
- need to be unambiguous- often highly stereotyped and ritualised
72
How can conflicts be avoided?
- maintaining social space- territories
- Appeasment & submission: dominance relationships
- Pre-fight displays
> fights = last resort
73
When is a fight most likely?
When contestants are evenly matched
74
What is persistence and perception?
- Even if evenly matched, one contestant may be prepared to persist for longer or escalate further because it has more to gain from winning.
> motivation e.g. Hunger, thirst
> perceived resource value e.g. Resident vs intruder
May lead to evolution signals of ownership
E.g. Territorial disputes in male speckled wood butterflies
Rule = owner wins.
75
How does eves dropping effect conflict?
- observing encounters between other combatants may affect the observers behaviour in subsequent encounters e.g. Siamese fighting fish
- females may also prefer males that they have seen 'winning'.
76
What audience effects can affect conflict?
- May be more aggressive if a potential mate is watching
77
What did Rohwer and Rohwer's experiment show?
Dominant male sparrows have a bigger black bib.
3 conditions painted birds black, gave them testosterone, painted them black and gave them testosterone.
> the 3rd condition was the only one that increased the observed status of the birds.
-this suggests that a signal must be supported by an appropriate behaviour.
78
What were the 2 ways in which Darwin suggested that sexually reproducing species can improve their chances of reproducing?
1. Compete successfully to survive & aquire resources allowing reporduction. > adaptions that aid Durval
2. By competing successfully for mating opportunities.
> characters that:
A) aid competition within one sex (usually males) for access to the other (intra-sexual selections)
B) enhance attractiveness of individuals within one sex (again usually males) to members to the other (inter-sexual or epigamic selection)
79
In what way do females invest more in offspring?
- costly large gametes
- internal development of young
- raising the young following birth of hatching
- finite egg production- limited number of mating oppertunities
> females prefer 'good quality' males
80
In what way to males typically invest less in individual offspring?
- Sperm 'cheap &unlimited'- unlimited mating oppertunity
- plus uncertainty of paternity
> males generally less choosy
- maximise success by mating with as many females as possible:
Compete for mates or resources of use to females (conflict displays) = male-male competition (intra-sexual completion).
or compete to attract females (courtship displays) inter-sexual competition
81
What are the functions of courtship?
- species, deme, class, individual recognition
- mate attraction
- mate choice: assessment of potential mates condition/quality
- coordinate reproductive behaviours & physiology between sexes (synchronisation)
- Maintian long term bonds & coordinate provisioning for offspring.
82
What do the displays of mate attraction signify? (Bird song)
```
- generally females prefer males with more complex songs &stamina for lengthy singing bouts
> tend to be:
healthier males
possess better territories
enhanced parenting potential
'good' genes
- Honest signals of male quality
- Courtship often involve combinations of components, often simultaneously exploiting diffenrtiation channels e.g. Male sage grouse
```
83
Describe the complex communication associated with con Frisch's honeybees dance language hypothesis
- direction of food relative to sun = direction of the straight run relative to gravity
- duration of straight run increases with distance at the rate of about one complete waggle per 30m
84
What is the human language based upon?
- Unbounded signal is set but based on 20-60 phonemes (distinct kinds of sounds).
85
What are the 3 components of a true language?
1. Use of symbols for abstract ideas
2. understanding of syntax
3. Displaced functional reference in humans
86
Do apes have communicate with language?
- lack motor ability to pronounce human sounds
- but can deal with other aspects of learning a complex language
> conclusion, non humans animals may learn to combine words/symbols to achieve goals but not proof they can do more than just associate a word/symbol with an object
87
Do chimps use symbolic representation in the same way that humans do? (Displaced functional reference)?
- Sherman & Austin (Savage-Rumbaugh 1986)
Sherman given container of food, but needs wrench to open it
Sherman punches new appropriate symbol on keyboard
- Austin then 'knew' wrench was needed, rather than some other tool & would hand it to Sherman.
- Sherman opens container and shares food.
> is this symbolic communication between 2 no humans?
88
What is the argument against?
- Epstein et al ' Jack and Jill'
> show that oigeons can learn behaviours that look like symbolic ommunication, but though a process of association rather than understanding the meaning of the symbols.
89
Parrots mimicking or comprehension?
- learned via spoken English to identify over 80 objects
- can quantify collection of up to 6 objects
- can identify shape and colour
- understands concepts such as same and different
- is this not using words to represent abstract concepts?
90
What is a body plan?
The basic structural design of a particular animal group.
- some animals have no symmetry e.g. Sponges
- most have at least one
- some are radially symmetric (where any plane along the main body axis divides the animal into similar halves).
