BIOL 1902 - Midterm Notes

BIOL 1902 – Natural History Introduction Natural History → the observation of living plants and animals – flora and fauna – and their interaction. It is an observational science. Someone with an interest in Natural History is a naturalist. Famous Naturalists 1. Linnaeus – Set the foundation for binomial nomenclature. 2. Charles Darwin – “world’s most famous” naturalist 3. John James Audubon – one of the world’s first “bird watchers” 4. Ernest Thompson Seton – semi-famous Canadian naturalist 5. Roger Tory Peterson – bird and nature field guides Adaptations - features or traits that offer plants and animals an advantage in solving problems. They are not acts of intelligence or planned solutions. They are features that have taken thousands or millions of years to evolve. - adaptations arise because of selective pressures. - adaptations can be physical, chemical, physiological, or behavioural → Selective pressures are a force of natural selection that acts on animals and plants, removing those that are less fit from the gene pool and selecting for traits that enhance survival or reproduction. → Abiotic pressures – pertaining to entities that are not biotic, such as wind or temperature. → Biotic pressures – pertaining to a living organism, such as an animal, plant, or bacterium. → natural selection – the driving force behind evolution; comprises many selective pressures including environmental extremes (abiotic pressures) and the selective power of plants and other animals. (biotic pressures) for example female mate choice, parasitism and predation. - the natural selection of adaptations are what drive evolution. Genetic Survival - genetic survival is the key to life – it is immortality. - all living things are driven to reproduce, and any trait that gives a plant or animal an advantage in reproduction or passing on genes can proliferate and become the trait we see today. Staying Alive (Textbook Chapter 1) Defences Physical Defences Camouflage / concealment → camouflage – colour, form, and possibly movement, that render an animal difficult to detect or recognize → concealment – avoidance of detection or recognition through the employment of camouflage → crypsis – the avoidance of detection by combining motionless behaviour with some form of camouflage (i.e. background matching) • Crypsis examples – Eastern Whip-Poor-Wills, American Woodcock - two common forms of camouflage or concealment 1 - Background Matching 2 - Disruptive colourization Background Matching → background matching – having an appearance that matches the general colour, contrast, and pattern of the local environment • Background matching examples – most ground nesting birds (earth tone dappled spots), American Bittern (vertical lines, points head up – like cattails), Gray Tree frog (changes colour to match surroundings), Snowshoe Hair (changes colour seasonally), Wood Thrushes (pale breasts with dark spots), deer fawn (brown coat, white spots). Disruptive colourization → disruptive colourization – a type of camouflage in which patterns create the visual illusion of false edges or boundaries, thereby breaking up the visual outline of an animal and rendering it unrecognizable. • Disruptive colourization examples – Killdeer (breast bands that are obvious when it’s standing but effective when it’s nesting), Canada Goose (chinstrap that works best when the head is lowered), Common Loon (coloured necklace), American Bittern and female Red-Winged Blackbird (vertical stripes along neck), Savannah Sparrow (Brown stripes on pale breast match vertical lines in grass habitat) → coincident disruptive patterns – a type of camouflage in which disruptive colouration on different body parts align in certain postures to create a continuous disruptive pattern • Coincident disruptive pattern examples - Leopard Frog (when sitting patterns on limbs and body match up to create a larger pattern) - supercilium – a plumage feature found on the heads of some bird species. It is a stripe which runs from the base of the bird's beak above its eye, finishing somewhere towards the rear of the bird's head. (supercilium examples – Chipping Sparrow) - eyeline – a distinctive line across the head of the bird through the eye (eyeline example – Chipping Sparrow) Masquerade → masquerade – a form of camouflage in which an animal’s body is shaped like a piece of its environment (i.e. twig) or something inedible (i.e. bird faeces) • Masquerade examples – Angle Winged Butterfly (dead leaf mimic), Inchworm (twig mimic), Walking Stick insect (looks like a twig), Treehopper (thorn/bark mimic), Luna Moth (live leaf mimic), Giant Swollowtail Caterpillar and Viceroy Caterpillar (bird dropping mimic) Bicolouration → bicolouration – a form of camouflage in which one surface is dark and the other is light, allowing background matching from two visual perspectives; generally a trait of small animals inhabiting the surface of aquatic habitats • Bicolouration examples – Whirligig Beatles (white on bottom, black on top), Notonectidae also called Backswimmers (black on bottom, white on top, swim on their backs) → countershading – a type of camouflage in which the lower parts of a body are lighter than the upper parts to offset the three-dimensional effect of shade by creating a uniform or flat appearance; also called self-shadow concealment or obliterative shading • Countershading examples – White Tail Deer (white belly to hide shadows) Startle Patterns Colourful patterns → startle patterns – bold and often colourful patterns that are exposed suddenly to startle a predator; sometimes serve a deflection or distraction role. - startle patterns are usually hidden until needed • Startle pattern examples – Underwing Moths (genus: Catacola – beautiful behind – they have colourful underwings), Gray Tree Frog (yellow under legs), Ring-necked Snake (yellow belly), Giant Swallowtail Caterpillar (osmeterium) → osmeterium (osmeteria, plural) – an eversible gland in the head of swallowtail caterpillars that, when extruded, resembles a snake’s tongue and emits a foul odour. Large conspicuous eye spots → eyespots – round patterns that look like eyes; often used as startle patterns or to make an animal look like a larger species. • Eyespot examples – Sphinx Moths (eyespots), Eyed Elaters and Eastern Tiger Swallowtails (large fake eyes to appear as larger animals) Deflection / distraction features → deflection patterns (distraction patterns) – patterns that direct a predator’s attack to a non-vital part of an animal’s body; some deflection patterns first serve as a startle pattern. → deflection structure – a structure on a non-vital part of an animal’s body that directs a predator’s attack to it. → autotomy – in animals, the shedding of a limb that usually, but not always, grows back; self-amputation • Deflection examples – Swallowtail moths, Eastern Tailed Blue Butterfly (tails that look like antennae with eye spots on the back look like heads), Five-lined Skink (blue tail detaches, grows back smaller, autotomy), Crane Fly (legs detach easily, do not grow back, autotomy) Constructed camouflage structures • Constructed camouflage examples - Spittle Bug (hides in foamy spit it excretes), Woolly Aphids (hides in fuzzy mould-like webs), Leaf Roller (uses silk to roll a leaf and hides in it), Sumac Gall Aphids (hide in plant swellings), Caddis Fly larvae (create little houses of debris on the bottom of aquatic habitats.) Protective structures Body armour • Body armour examples – Millipede (coils up exposing hard exoskeleton), clams and snails (calcium protective shell), beetles (hard backs with grooves to tuck in legs and antennae), turtles (Box Turtle can completely close shell, Blanding’s turtle can partly close shell because of a hinge on their anterior, Snapping Turtles defend themselves aggressively; they cannot withdraw into their shells for protection) Constructed enclosures • Constructed enclosures examples – Eastern Tent Caterpillar (live in groups. Construct a big tent, exit tent at night to feed), Fall Webworms (construct a tent that includes their food source) Hair/fuzz → guard hairs – the longer, coarser hairs that make up the outer coat or pelage of a mammal • Hair/fuzz examples – Gypsy Moth Caterpillar, Tussock Moth Caterpillar (hairy, roll in to a ball when threatened to protect underside), Woolly Bear Caterpillar (stiff, spine-like hairs), Porcupine (quills are modified guard hairs, quills have antibiotics on them in case of self-impale accidents) - Black-billed Cuckoos and Yellow-billed Cuckoos eat fuzzy caterpillars; fuzz is removed in their crop, oesophageal pouch, and then coughed out. Chemical Defences → aposematic colouration – bright colours that warn of a strong defence; also called warning colourization → inducible defence – a defence that is only present when a plant or animal is under attack → sequester – obtain from another source; usually achieved by eating something not manufactured by the sequestering animal (i.e. poison, toxins) → terpenoid – a group of important plant chemicals that lack nitrogen used primarily for metabolic functions and secondarily for defence (sequestered by some animals for chemical defence) Toxic hair / spines - hairs + poison = poison spines • toxic hair / spines examples – Monkey Slug, Io Moth Caterpillar Bad taste / poisonous → alkaloids - bitter tasting nitrogenous chemical compounds used for defence • Bad Taste examples – Milkweed Beetles, Milkweed Bugs (orange/black aposematic colouration), Lady Beetles (make their own alkaloids) Exuded poison / spray / sting → cardenolide (cardiac glycoside) – a type of terpenoid used as a chemical deterrent that, in large doses, acts as a heart poison → cantharidin – a type of terpenoid typically used as a chemical defence by Blister Beetles • Exuded Poison Examples – Red Eft Newt (poison skin), wasps and bees (stingers), skunk (sulphur alcohol spray, black and white nighttime aposematic colouration), Monarch Butterfly Caterpillar (sequesters cardiac glycoside from milkweed), Sawfly Larvae (poison bubbles out of the mouth), Blister Beetles (Spanish fly (cantharidin) comes out leg joints), Dytiscid Water Beetles (chemicals shoot out anus) Mimicry → mimicry - whereby an animal takes on the appearance of something else (i.e. an inanimate object such as a piece of bark or leaf; another animal, one often aposematically coloured) Müllerian mimicry → Müllerian mimicry – whereby two or more animals (i.e. Milkweed Beetles and Milkweed Bugs) share similar appearances and each honestly advertises some form of defence • Müllerian mimicry example – bees and wasps Batesian mimicry → Batesian mimicry – whereby a harmless animal, the mimic, resembles (behaves, looks or sounds like) another animal, the model, that is toxic or otherwise well defended → model – in Batesian mimicry, the well-defended and usually aposematically-coloured animal that the harmless mimic resembles (behaves, looks or sounds like) - the success of Batesian mimicry depends on there being more numerous models than mimics. • Batesian mimicry examples – Monarch Butterfly and Viceroy Butterfly – bees and wasps and a bunch of different types of Hoverflies that look like them. Behavioural Defences Aggressive mimicry → aggressive mimicry – whereby an animal uses behaviour or appearance (i.e. a modified body part) to resemble an edible item or harmless animal for the purpose of deceiving prey • Aggressive mimicry examples – Photuris Fireflies (fireflies are beetles) females eat Photinus Fireflies after attracting them with mating blink signals, sequesters steroidal toxins from the males. Thanatosis → thanatosis – feign death • thanatosis examples – Hog-nosed Snake (puffs up to look big, if that fails, play dead), Blister Beetle, Opossum Flocking / schooling / yarding → communal roost – a site in which a large number of birds gathers to spend the night. (Communal roost examples – Rock Pigeons, Red-winged Blackbirds, Turkey Vultures) → single-species flock – a flock of birds consisting of only one species → mixed species flock – a flock of birds comprising more than one species; often formed in migration or in winter to provide enhanced vigilance. → deeryard – an area where White-tailed Deer gather for the winter; often lowland dominated by Eastern White Cedars - birds flock, fish school, deer yard Social Insects – Group defence - pheromones summon other insects in the hive/nest to join the attack Mobbing – Pre-emptive defence → mobbing – a defensive response in which animals (birds usually) noisily harass a potential predator → pre-emptive defence – in reference to mobbing, a behavioural defence that may serve to drive away a predator before it has a chance to attack → locatable alarm call (locatable distress call) – an avian alarm call with a low frequency and acoustic qualities that allow other animals to easily locate the caller; often used in conjunction with distraction displays, or with mobbing Distraction or warning behaviours - some animals raise a white tail or otherwise indicate to predators that they have been detected. Others hiss, stamp their feet, emit other warning sounds or posture to try to look larger • examples – white tail deer (tail goes up, deer runs), Cottontail (white tail) Enlisting help for defence - Woolly Aphids, Froghopper, Treehopper excrete sugar-rich drops that attract Carpenter Ants. The ants defend their “herds” from predators and harvest these drops. Vigilance Pressure sensitivity → lateral lines – on the sides of fish and some aquatic amphibians, a row of special sensors (neuromasts) that are sensitive to pressure changes and possibly electromagnetic fields (at least in sharks) - snakes can sense vibration along the ground for location detection Olfactory Vigilance → olfactory – of or pertaining to the sense of smell → Jacobson’s organ – a sensory organ for enhanced detection and analysis of airborne scents usually located in the palate of an animal’s mouth; also called vomeronasal organ • Olfactory Vigilance examples – Moose (large surface area in nasal passages means better sense of smell, also has Jacobson’s organ), Snakes (“taste” smells in the air, tongue is forked so the smell direction can be determined), Auditory Vigilance → tympanum – the membrane associated with hearing in frogs and many insects • Auditory Vigilance examples – Tiger Moth (tympanum to hear bats, clicks aposematic back at bats because they are poisonous), Mantid (tympanum). Moose (big ears, also known as pinnae , independent swivel) Visual Vigilance → tapetum lucidum – in the retina of night-active animals, a layer of cells that reflects unused light outward toward the receptor cells; produces eyeshine - eye placement on head can increase field of view. More visual overlap increases depth perception in that area but decreases overall field of view. - eye construction. Cones see colours. Each cone has a nerve connection. Cones are used when light is ample. Rods see brightness. Many rods share a nerve connection. Rods are used in low light. - most prey animals have eyes on the sides of the head to watch for predators. most predators have eyes on the front of the head to increase depth perception and visual acuity. • Visual vigilance examples – American Woodcock (eyes placed near back of head, can see when beak down in mud to feed), American Bittern (eyes placed near beak so it can see when head up in alert posture), Flying Squirrel (nocturnal animal, has big eyes) Fighting Back (Textbook Chapter 6) - plants are always under attack Physical Defences - Aposematic colouration happens in plants → automimicry – whereby one part of an organism resembles a different part of the same organism - New buds may resemble prickles, this is automimicry External Protective outgrowths Spine → spine – a sharp highly lignified, non-living protective structure derived from a modified leaf or part of a leaf • Spine Examples - Scotch Thistle (spines) Prickle → prickle – a sharp, protective outgrowth of the epidermis; a modified trichome • Prickle Examples - Prickly Ash (prickles) Thorn → thorn – a sharp, protective outgrowth derived from a modified branch of a plant • Thorn examples - Hawthorn (thorns), Honey Locust (thorns) Internal Protective structures Trichomes → trichomes – a plant defensive hair, often clubbed; can be non-glandular or glandular - glandular trichomes – contain volatile oils and other secretions produced by the plant for defence • Trichome examples – Ragweed (trichomes), Mullein Leaves (trichomes), Stinging Nettles (glandular trichomes), Water Smartweed (inducible trichomes if the water goes away) Digestibility reducers → digestibility reducers – a compound that makes cell walls and other plant tissues difficult to digest (i.e. the structural elements cellulose and lignin), or that binds to digestive proteins in an animal’s gut rendering them ineffective (i.e. tannins) Plant Cell Construction → cellulose – a structural element in cell walls that is also a digestibility reducer; most plants are about one third cellulose → hemicellulose – a binding agent that holds cellulose bundles together in plant cell walls → pectin – a binding agent that holds cellulose bundles together in plant cell walls - microfibrils – strands of cellulose that are bound in small bundles - fibrils – larger bundles of cellulose microfibrils → silica – silicon dioxide; a structural component of tissues especially common in horsetails and grasses → phytoliths – discrete bodies of silica in the tissues of plants; also called plant opals or silica cells → cutin – a waxy compound that is one of the main components of cuticle that is hard to digest for animals. Sclerified structures → sclerified – tissues hardened by the addition of sclereids → sclereid – a sclerenchyma cell (usually dead) that is rigid and heavily fortified with lignin often present in large numbers in seed coats and pits; sometimes called “stone cells” → lignin – a chemical compound, the main focus of which is to provide support to woody tissues Chem