Animal Adaptations Arthropods Biological Control (Integrated Pest Management). Animal Adaptations. Correlations of life choices with structural and physiological changes. Things to think about. Why choose? = competition – or avoiding it. . Reproductive cycles.
Animal AdaptationsArthropodsBiological Control (Integrated Pest Management)
Correlations of life choices with structural and physiological changes. Things to think about
Why choose? = competition – or avoiding it.
Coral life cycle. The medusa (like a jellyfish) is diploid, but male or female or both. Meiosis in it produces eggs and sperm – planula is a dispersal phase
What affects the choices?
Sessile vs motile?
Which systems affected?
What limits placed on where you live- why?
Reproduction: sexual, motile sperm find egg, but also cloning (asexual) plus regeneration
Food; in water, mostly ocean (why?)
Dispersal: larvae with flagella.
Protection: regeneration, spicules
Symmetry: assymetric vs
Which leads to what systems?
Nerves and senses and brain concentration.
One of the major senses: Light sensitivity
Nearly all cells have it – goes back to bacteria.
Higher animals – special light sensory devices – function
detect light – use for clocks – telling seasons, etc.
detect movement only - protection
identify shape; - leads to memory.
How to take an image – break it into bits of information – transmit to brain for storage and processing?
Note: diurnal vs nocturnal
diurnal ; shape perception = eyes
nocturnal: -vision – see movement, not shape.
shape perception in dark = radar, sonar – bats and porpoises
What if you are motile and can’t find a mate?
Under what conditions is this likely to occur??
Parasites in body
Whiptail lizards, among others
Parthenogenesis = egg develops without
Why here? (are males that repulsive?)
What systems required to gain in size? Why?
Circulation, respiration, excretion, skeleton
Skeleton – a requirement of size
Limitations of each?
Muscles compress compartments – push the worm forward. Setae(spines) hold portions of body to ground.
Note cross – sectional diameter.
keep wet gills
insects – spiracles.
Large surface area in contact with environment – skin respiration
Crab gills – feathery under surface for protection
Fish gill structure – large surface area
Terrestrial vs aquatic:
Which systems affected?
As with plants.
How to avoid drying out
How to breathe – get oxygen.
Specialized food; molluscs, fish, ants,
Which feeding type leads to:
more active life?
larger population size?
Cold vs warm blooded: - what are the advantages, disadvantages of each?
What conditions might favor the development of warm bloodedness?
Figure 40.9 Ectotherms and Endotherms React Differently to Environmental Temperatures (A)
Mammals as maxitherms.
How to deal with harsh conditions?
Like a plant: - survive as egg (seed)
- adapt (fur, evaporative cooling, etc)
-migration – avoid bad conditions
Allen’s rule; larger extremities in warmer climates
Butterflies and moths
Bees, ants, wasps
Trilobites – stem group, marine
Metamorphosis vs incomplete metamorphosis.
Find a natural parasite or disease of the pest.
Breed it, and release it into the environment
Here parasitic wasps lay eggs on caterpillars, kill them so they won’t eat a crop.
Screw worm fly
So: knock the population down with pesticide
release a lot of sterile males 10-100 for each fertile male
get rid of flies in one year.
Moth and caterpillar crop pests
Females release a pheromone to attract males.
Synthesize the pheromone
Place in traps around the crop
Poor female left forlorn in the field.
Life cycle – juvenile hormone absence allows pupa formation.
So synthesize the juvenile hormone, spray on crop
Caterpillers never metamorphoze, never pupate.
No adults formed, no increase in population.
New technique – Bt corn etc.
Insert the genes for a bacterial toxin into a plant crop (plus the genes to turn it on, etc.
Bt is a bacterial toxin against moth and butterfly caterpillers.
To kill a susceptible insect, a part of the plant that contains the Bt protein (not all parts of the plant necessarily contain the protein in equal concentrations) must be ingested. Within minutes, the protein binds to the gut wall and the insect stops feeding. Within hours, the gut wall breaks down and normal gut bacteria invade the body cavity. The insect dies of septicemia as bacteria multiply in the blood. Even among Lepidoptera larvae, species differ in sensitivity to the Bt protein.
Why are biological controls good?
So why are chemical pesticides overwhelmingly preferred??
By the Industry (Dow and Monsanto Chemical)