Lecture 11: Co- Evolution Flashcards
Four levels of the study of animal behaviour
proximate causes
genetic-developmental mechanisms (Ontogeny)
- effects of heredity on behaviour
- development of sensory –motor systems via gene-environment interaction
-> Ontogeny
Sensory-motor mechanisms (Physiology)
- detection of envmtl stimuli (nervous system)
- responsiveness (hormones)
- responsive abilities (skeletal muscular system)
-> Physiology
ultimate causes
Historical pathways leading to current, behavioural trait (Phylogeny)
- events occurring in evolution over time
-> Phylogeny
Selective processes shaping behavioural trait (Fitness)
- past and present usefulness promoting lifetime reproductive success
-> Fitness - discussed in lecture Adaptations to environment, coevolution with other species; Sexual selection; kin selection
interrelated
Proximate and ultimate causes are
Tinbergen‘s 4 „Why
Example for ultimate, evolutionary
explanation
Understanding Monogamy in Microtus ochrogaster monogamous – exception among rodents
Behaviour:
* females are promiscuous (test: 55% mate again, Wolff et al. 2002)
* mate guarding by males increases reproductive success of males
* Basis for monogamy
Example Monogamy in Rodents : Selective process
- Adaptation:
- more oxytocin receptors in brain (binding hormone)
- more oxytocin is produced
Coevolution- Concepts, theories, applications
- Coevolution
- Coevolutionary arms race
Examples and study approaches:
* Symbiosis
* Parasitism
* Adaptations to hosts
-Escaping parasitism
-Diseases and zoonoses
* Predation/antipredatory behaviour
Coevolution def.
“Nothing in Biology makes sense except in the light of Evolution“ (Dobzhansky 1973)
- > Community evolution< evolutionary
interactions among different kinds of organisms where exchange of genetic material is … absent. An (overlooked ) factor in organic diversification - Coevolution : patterns of interaction between to major groups of organisms with a close and evident ecological relationship “ (Ehrlich and Raven 1964)
Keep in mind: Selection also happens between different species
Importance
of coevolution for Conservation
- Invasive species : stripped of co.evolutionary networks
-Missing pathogens
-Native prey without antipredatory adaptations
-Heritability and learning - relocation / reintroduction of species to
incomplete communities
if you know hat is misseing, u can reintroduce species
The phenotypic interface of Coevolution
Coevolution Processes/facts
- Evolutionary process
- Reciprocal selection
- Over long time periods of phylogeny (over many generations; -> time scale in generation, not years or days..)
- Restricted to species pairs with strong reciprocal selection
- Result : Coadaptations in both species
- Performance traits at the frontline of selection
-Movement abilities - Mimicry
- Toxin resistance
- Hunting strategies
- Sets of traits (Syndroms) performance syndroms because they are a correlation between:
-Physiology + Morphology + Behaviour - Co evolutionary arms race : reciprocal adaptations over time
Positive / neutral interactions
(Probiosis)
symbiosis, mutualism, neutralism
– Symbiose:
* Profitable for both
* Gradual Differences in reciprocal dependence /benefits (oblicatoric, facultative…)
oblicatoric: has to be very tight relationship
Negative interactions (Antibiosis)
- Competition
- Trophic interactions (how is energy transferred trhough the ecosystem -> someone is eaten all the time)
Coevolution Host Parasite
- Complexe Lifecycles , including host changes
- Adapted to immunosystem of host
- High variabilty in in P und W genetik
- Coevolutionary arms race
-> Pushing evolution of hosts : RED QUEEN Effekt
RED QUEEN: have to evolve the whole time to stay at the same place/relationship
Coevolution Host Parasite:
what does the Parasite
has to do?
- Overcome defenses of host
- Learn communication of host
- Makes himself dependent on host
- Can utilise host as ressource
- Can get extinct if host adapts
Most famouse exampmle for Broodparasitism
Parental investment is the most costly
behaviour in many avian species->
potential for parasitism
Cockoo
Adaptations
of cockoo
- Learning to count
- FAST deposition of eggs & HIDDEN removal of one host egg
- Eggs mimck the host eggs (even in UV range)
- juveniles mimick the host hatchlings
Juvenile:
* Destroys competitors
* Extreme begging behaviour
-> Cuckoo chick is fed as much as an entire
brood (parents can not say no because of the big and red beak and moving and screaming)
New host species in Japan: Azure-winged Magpie
Counterstrategies
of hosts
- abilty to count
- Recognition and removal of parasitic eggs
Coevolution of the eggs
- Parasites are forced to mimic the hosts egg -> Evolution of host specific lineages (gens, host race, host specific lineage of brood parasite)
- Egg copies are better in host
species that remove parasites eggs
Hypothetic
evolutionary path
Example: Myxomatosis
- From South American Forest rabbit (Sylvilagos brasiliensis), mild disease
- Deadly in European rabbits; Oryctolagus cuniculus
- 1950 introduced to Australia pest control to minimize the introduced rabbits
- In the first year it was very deadly -> strong slective
- in the third year already adaptions for this are shown
Red Queen´s Race
Every improvement in one species will
– lead to a selective advantage
– improve fitness
– guarantee a larger share of common resources
– induce “catch-up” strategies of the other parts of the
system
**Fitness increase in one system will lead to a decrease in any other related system
Example: New Zealand Snail *Potamopyrgus antipo
Invasive elsewhere in the world
* Successful since clonal (asexual)
* Parasitic trematode Microphallus sterilises individual snails
* Untersuchungsgebiet: Poerua See & Ianthe See in New Zealand
* Host specific for each lake
Local adaption: Parasite is most successful in hosts from the same lake
- Parasite is well adapted to the most abundant clones from its origin
- Rare clones are rarely infected
- Parasite does not distinguish common and rare clones from a different lake
At a different point in time other clones would be most abundant -> genetically different after years
Red Queen Additions
- At any other given point in time the system would be differnt : other clones would be more common. The combination of the population changes to stay in the same place.
- Evolution of sex : Recombination of host genome to escape adaptation of parasites compensate the two fold costs of sex
(males will not produce offspring directly. only females can produce offspring -> you can loose yor sucsessful genotyp because of recombination) - Central topic of Evolutionary ecology
Two fold costs of sexual reproduction
- Asexual female produce
twice as much females as
sexual females - Asexual females maintain
successfull genotypes
clonal - “two fold costs of males “
(Maynard Smith 1971, 1978)
Experimntal evidence: MIxed population experiment of sexual and asexual NZ snalis
Predator- Prey: Co-evolutionary arms race
NOT Individual adaptations (learning , improving search image..)
BUT Evolutionary adaptations (ability to learn , sensory and locomotory system)
Coevolution examples: Plant defenses and Adaption by herbivores
Plant defenses:
Sekundary compounds (toxins, repellents) are induced by damage through herbivores
Adaption by herbivores:
-Detoxification
- Accumulation
- **Aviodance behaviour
