Chapter 44: Animal Behaviour and Responses to the Enviornment Flashcards
behaviour
defined as the way in which organisms respond to a particular situation or stimulus
single-cell organisms exhibit complex avoidance behaviours
- swimming away from light or predators
- ## motile, single-celled ciliate Senior coeruleus is capable of decision making and learning
- fungi and plants have senses analogous for those of animals, exhibit behaviour
- while learning, memory, and behaviour have long been associated with animals having nervous systems, there is growing acceptance that non-neural organisms such as bacteria, slime moulds, and plants can also exhibit complex behaviours
the prey species also study the behaviours of their predators and develop defensive strategies against them, how is this info passed down
- this information is passed down from one generation to the next
EXAMPLE: KILLER WHALES
- British Columbia
- mother and grandmother orcas filmed teaching young orcas how to spy-hop to locate seals and how to leap out of the water and use their tails to stun and kill their prey
- killer whales off the coast of Argentina teach their young how to self-strand, to surprise and capture sea lions on the beach
- the orcas surf on incoming waves to grab seal pups, becoming stranded themselves in the process, but use the following wave to pull them back to deeper water
- antarctic orcas use wave-washing as a strategy for hunting seals
what is wave-washing for orcas
- basking on ice floes, this is cooperative behaviour in which groups of orcas first chip away at the ice floe, diving below it at the last moment and allowing the wave they have created to wash the seal off the far side, where other orcas in the pod are waiting to capture it.
- when young orcas are present, the pod will often push the seal back onto the ice floe and then regroup to repeat the behaviour again for the benefit of the young
the study of plant and animal behaviour by humans was a natural progression
- 12 000 years ago, all humans were hunter-gatherers
- indigenous hunting societies around the globe have relied on knowledge of the behaviours of their food species for survival
- this knowledge of the relationship of living things with one another and with their environment has traditionally
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most knowledge of behaviour begins with
observation
what do organisms do in response to different stimuli
- most knowledge of behaviour begins to observation
proximate causes
refer to the mechanistic bases of the behaviour
ultimate causes
refer to the evolutionary bases of the behaviour
nature
- how much of an organism’s behaviour is a function of what they inherited as opposed to be environment and setting in which they develop and are nurtured
instinctive behaviour
- behaviours that are inherited
nurture
- behaviour based on the environment and setting in which they develop and are nurtured
how can instinctive behaviours be grouped
- feeding
- defence
- mating
- parental care
what do we assume about instinctive and nature
they have a strong genetic basis and that natural selection has preserved instinctive behaviours because they construe adaptive advantages
learned behaviours
determined by the environment an animal grows up and lives in
are not performed accurately or completely the first time they respond to a specific stimulus
behaviours change in response to what stimuli?
the environmental stimuli and individual experiences as it develops
how do behavioural scientists generally define learning
process in which experiences change an organism’s behavioural responses
young herring gulls
- the responses of young herring gulls chicks to cardboard cutouts of an adult herrings gull head and bill
- they waves these models in front of the chicks and recorded how often a particular model elicited a pecking response from the chicks
- chicks peck on the red side at the bottom of an adults mouth to have the adult open their beak wide and feed them *
results: young gulls pecked at the model of the bill with a red spot almost as often as pecking at just a head with a red spot, but barely pecked the model without a red spot
= begging behaviour by young herring gulls is triggered by SIGN STIMULUS = red spot on parents bill
fixed action patterns are triggered by what form of stimuli
sign stimuli
- young herring gull chicks use a begging response, a fixed action pattern to secure food from parents by pecking on red spot on bill
the role of natural selection in moulding behaviour
- moulded behaviour of some parasitic species to exploit the relationship between sign stimuli and fixed acton patterns for their own benefit
- in effect, they may break another species’ code
i.e. birds that are brood parasites lay their eggs in the nests of other species of birds, when the parasite’s egg hatches, the nesting mimics sign stimuli ordinarily exhibited by its host’s own chicks - the parasitic chick begs for food by opening its mouth, bobbing its head, and calling more vigorously than the host’s chicks
female greater honeyguides
lay their eggs in the nests of several host species that nest in dark hollows
- greater honeyguides are not territorial, so more than one female may lay her eggs in the nest of a host
When a female lays her eggs:
- a female greater honeyguide minimizes future competition among nestlings by selectively piercing the eggs of other greater honeyguides in the nest
After hatching:
- greater honeyguides chicks kill other nestlings, whether conspecifics of the young of the hosts
- both egg piercing and killing nestlings increase the chances of the chick surviving and reproducing
genetic differences between individuals can translate into
- behavioural differences between them
- single genes do not directly control complex behaviour patterns, the alleles of the gene instead determine the kinds of enzymes that cells can produce, influencing biochemical pathways involved in the development of an animal’s nervous system
- the resulting neurological differences translate into behavioural differences between individuals that have certain alleles and those that don’t
Wingless pathway
- controls a series of development interactions shared by almost all eukaryotic organisms, most of which do not possess wings
- named after the original discovery of the wingless gene
- mutant genes of the pathway (fruit flies) cause alterations in the wings and other segmental structures
Nardos Lijan experiment on the wingless pathway
- constructed an artificial copy of the Dv11 gene with the central section scrambled so no functional proteins could be made
- introduced the artificial proteins into embryonic cells, and they interbreed the heterozygotes to produce individuals that carried two copies of the altered Dv11 gene and no normal copies
= individuals without the normal gene copies are knockout mice because the normal gene is completely missing