Evolutionary Adaptations and the Marine Environment Flashcards
what does Megaptera novangilae mean?
large-winged new angel
What would you tell Darwin if he arrived spontaneously?
Might be a test question. Think about it.
Ultimate/proximate question
Ul: Why. why it occurs the way it does.
Pro: How. how does it work?
Define evolution
‘descent with modification’
‘change over time’
who coined the term ‘survival of the fittest’?
Spencer
What is the concept of evolution?
the concept that all living organisms are related by an unbroken chain of events
What are the facts of Evolution?
- things have changed (fossils)
- things continue to change (evolution in action, Darwin’s finches, intro of spp. and co-evolution)
- genetic evidence (ATCG, 60 similar genes, universality of function)
- nothing contradicts.
What is the theory of evolution?
- all organisms produce more offspring than can possibly survive (Malthus)
- Theory of natural selection
What is the theory of Natural Selection? (1989)
LONG VERSION
- there is variation
- variation is inherited
- there are reproductive consequences associate to the variation, some survive to reproduce more than others.
Natural selection: what are the three big points?
SHORT VERSION
- variation
- heritability
- reproductive consequences
teleological
designed and directed towards a final result
what is a more appropriate language to define ‘advanced and primitive’
derived and ancestral
Define adaptation
Physical, morphological, behavioral characteristic that allows an organism to survive in its environment better than without.
What are the adaptations of a humpy to its environment?
- pectoral fins
- bubble feeding
- Dr Fred Sharpe.
- baleen plates
Describe baleen plates
0.5-3.5m
90kg
broader at the gumline
sieves or venetian blinds
Name some mysticetes
baleens,
humpy, blue, grey
name some odontocetes
toothed, dolphins, porpoises, killer, sperm whales
What MMammal families are from order Carnivora?
Otaridae (fur seals) Phocidae (earless seals) Mustelidae (otters) Ursidae (bears) Odobenidae (walrus)
How are phylogenetic trees produced, and how is it arranged?
Produced: DNA sequencing (roots, branches) and morphology (present, absence, gradient)
Decay indices.
Arranged by x-axis=time, y-axis divergence
when did marine mammals first diverge?
65mya. marsupials first, placentals second. bear like ancestor.
Who did cetaceans derive from? when?
even-toed ungulates. Probably ungulates.
50mya
what adaptations occured for mammals to become marine?
- middle ear rotated
- drag reduction (legs, genitals, external ears, hydrodynamic body shape, hair), tail/fluke, physiological
what are mal-adaptations?
adaptations may be imperfect because of time lags.
name a mal-adaptation
king crab pleopod asymmetrical
estivation
depression in aerobic metabolism during the hot dry season. sort of like hibernation
Prosobranch and pulmonate on slide 32
what does it all mean??
what is the behavioural adaptation of Nucella in regards to their eggs?
They use spermatotheca (hold eggs) until its a good time, then egg capsules to nurse the eggs into embryos.
-How do they behave in wave exposed/protected in regard to egg to embryo ratio?
FRTS
fast repetitive tick sounds
Why might herring make sounds?
- buoyancy adjustments
- prey consumption
- schooling (size assortative, contact calls)
- Foraging (food calls/manipulate prey, adjust buoyancy to better catch prey)
- aggression
- reproduction
- anti-predation (acoustic flack, deterrence, distastefulness
- echolocation (navigation, food, friends)
how much greater does sound travel in water than in air?
4.7 times
how does hearing differ between terrestrial and marine animals?
Terrestrial: external morphology, pinna, enhanced sound reception
Aquatic: sonar, other structures of the head.
describe echolocation
- sound waves pass uninterruptedly through the water
- encounter an object
- refractive index different from water
- waves strike
- reflected and return to the source
- the time difference between sound production and receivership = distance
what is the melon
a fat tilled structure which acts as an acoustic lens
Pelagic zones
- epipelagic
- mesopelagic
- bathypelagic
- abyssopelagic
Benthic zones
- littoral
- bathyal
- abyssal
- ultra-abyssal
name some nekton of the pelagic, and where they would be found
nekton: bony fish, sharks, rays, marine mammals, reptiles, birds
Holoepipelagic: thresher shark, tuna, marlins
Meroepipelagic: Herring, whale shark, dolphin, salmon
which are the two types of swim bladders?
- physostomatous: soft-rayed fish, salmon
- physoclistous: spiny-rayed fish, rockfish
name a type of fish which doesn’t have a swim bladder
bonito, mackerel (lift from body surface or pectoral fins)
How do squid regulate buoyancy?
ion replacement:
heavy sodium ions with lighter ammonium ions
