Chapter 10 Co-Evolution

1. Chapter 10 Co-Evolution Co-evolution involves the joint evolution of two or more species as a consequence of their ecological interaction. Each species is partially dependent upon or threatened by the other, thereby producing reciprocal selective pressures.

2. Symbiosis means living together, an ecological coupling of two or more species in a co-evolutionary relationship.If both partners benefit, the relationship is mutualism.If one benefits the other is at least not harmed, is commensalism.When one species loses and the other gains; predation (predator and prey), parasitism (parasite and host), herbivory (herbivore and plant).

3. Spines; cactus, with projecting thorns

4. Chemical warfareSome herbivores have tough tongues and steely mouths Small insect herbivores evade the spines by simply navigating around them to Plants under such attack often produce chemicals that are unpleasant in taste or even toxic in effect;secondary chemical compounds.Their central function is to provide the plant with chemical weapons to frustrate natural enemies.

5. Nicotine in tobacco plants; against herbivorous insectsdisrupting their metabolism and probably carrying a foul tasteSeeds of some morning glories include d-lysergic acid, close chemical cousin to LSD, with hallucinogenic properties

6. Members of the mustard family include mustard, radish, horseradish, cabbage, and watercress, all of which contain mustard oil.Some plants, such as milkweeds and dogbane, produce milky sap containing cardiac glycosides, named for their potentially lethal effects on the heart of vertebrates but equally toxic to many insects.

8. 殺不完的昆蟲 Plants have been in chemical conflict with herbivores, insects in particular, for millions of years.When humans, late participants in this chemical warfare against insects, are quickly defeated by insects that evolve resistances to humans –engineered chemical pesticide. Insects have been waging this old battle of chemical warfare against plants for millions of years. 身經百戰的昆蟲

10. MutualismsWhat they do not digest, they excrete as a droplet of water containing undigested sugars, known as “honeydew.”Some species of ants collect this excreted honeydew, using its sugars as a resource.Directly solicit the aphids to release the drop of honeydew. And in some interactions, the ants may actively protect the aphids from their predators,Aphids benefit from the protection afforded by the attending ants.

11. Ants and Aphids-Mutualism • These ants tend their “herd” of aphids, which in turn secrete fluids rich in sugars drunk up by the ants.

12. Ants and Fungus Attini ants, denizens of the New World tropics, culture and then eat the fungus (genus Leucocoprini) in safe, underground “gardens” within their burrows. The fungus is grown on a mixture of excrement fertilizer, from the ants, and fresh plant material gathered aboveground by the ants.

13. Leaf-cutter ants—mutualism The ants chew up the leaf pieces into even smaller pieces (1-2 mm), munching them into a pulp, and insert the pulp into the garden plots

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15. Ants then pluck tufts of the fungus Overall, both ants and fungus benefit.For the ants, it is a sustainable crop. For the fungus, it is care and nurturing.Ants chew up the antifungal defenses of the plant (such as its waxy coating), and the fungus degrades the anti-ant defenses (insecticides) of the plant, such as its secondary chemical compounds

16. This chummy world of ant farmer and fungus garden invites the invasion of “weeds.” The weed is a virulent parasitic fungus (genus Escovopsis).In response, ants carry on their bodies a bacterium (genus Streptomyces) that produces antibiotics 所屬網頁 http://grani.ru/Society/Science/

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18. Acacia tree (Acacia cornigera) Ants (Pseudomyrmex ferruginea). Along its branches, the acacia provides the ants with small pools of nectar drunk up by the ants and Beltian bodies picked and fed to ant larvae; further, the inflated, hollow thorns of the acacia provide a home in which the ants live. The ants protect the acacia from browsing mammals; The ants also attack herbivorous insects that alight on the acacia. Further, the foraging ants eliminate adjacent, competing plant species by eating their leaves.

19. Ants and Acacias-Mutualism

20. The ecologist, Daniel Janzen, removed the ants from their associated acacia trees by clipping off branches that held the colony of ants or by temporarily eliminating the ants with insecticide spray. Quickly became vulnerable to unchallenged attacks by phytophagous insectsthe acacias were overgrown by competing shrubs and trees . Essentially, the ants provide a standing army for the acacias,

21. How it evolved Perhaps the first step would be the evolution of thorns by the acacia.Next, the facultative or casual use of these thorns as nest sites by tic association.Defoliates competitor plantsThe by-product of this attack would be to fend off acacia enemiesproduced supplementary food

22. Honeybees and Flowers Gymnosperms produce pollen, packets of sperm, carried usually by the wind to female ovules where fertilization occurs. Instead of wind, flowering plants often employ animal vectors, directed transfer agents, to carry pollen more or less directly from male to female flowers. Butterflies; hummingbirds; honeybees

23. Honeybees and Flowers The colors and smells both catch the attention of honey bees and, signal the availability of food and ripe pollen.Honeybees have special bristles on their legs-”pollen baskets”-which The honeybee gains a resource from the flower; the flower gains a traveling agent to deliver its pollen.

24. Honeybees and Flowers

25. Hummingbirds and flowersHummingbirds feed on insects, but they are outfitted with specialized long beaks and tongues to drink up nectarthey are specialized to tap resources supplied by flowers but they also act as pollinators as they move from flower to flower.Hummingbirds may visit one site only during a short block of time.

26. Hummingbird feeding on a flower

27. Angiosperms, which cater to hummingbirds as their pollinator, bloom during the spring as hummingbirds pass through on their way to northern breeding territories.Many flowers; tubular and narrow at their base, Tends to prevent roving insects from pirating nectar saves it for hummingbirds with long beaks and tongues

28. Practical and Functional Biologists placed around the grounds small, clear dishes of sugar water on colored backgrounds; attracts butterflyclearly preferred two particular colors, yellow and purple. These turned out to be the flower colors they preferentially visited as well.Our eyes do not see in the ultraviolet range of light, but the eyes of some insects do

29. Note the distinguishing nectar guides, the spots near the center of the flower.

30. Mutualism—fish • The small Spanish hogfish dashes into the mouth of a willing barracuda where it feeds on debris and parasites. The hogfish gains a meal and the barracuda gains a cleaning.

31. Mutualism—birds and crocodiles • This African crocodile relaxes and holds its mouth open. This signals Egyptian Plovers to enter and safely feed on fouling parasites and debris. The crocodiles gain a cleaning, and the plovers a meal.

32. Mutualism—oxpecker • This red-billed oxpecker forages for parasites on the backs of African ungulates. Here the oxpecker is working around the neck of domestic cattle. Parasites tend to collect along the back of the neck where scratching cannot dislodge them. The oxpecker gains a meal, and its customers get rid of parasites.

33. Commensalism“looking-glass” orchids, are visited not by bees, but by wasps.At first, that puzzled biologists. Wasps are usually scavengers and predators.For wasps, pollen is not a resource to be harvested. Looking-glass orchids do not even produce nectar, yet wasps visit, and hence the puzzle.

34. Not to find food but to satisfy the prurient interests of male wasps- for sex.It is not known for how long or for how many times a male wasp continues his unrequited quest, but looking-glass orchids are a very successful group of plants.

35. The skunk cabbage is named for the unpleasant odor, human senses. Humans often describe this plant as smelling like rotting meat or dung. But to the sensitivities of many insects, these welcome odors signal useful resources. Flies and scavenging beetles seek out decaying meat or dung, respectively, where they lay their eggs.

36. When the flower ripens, it warms, up to 40℃, volatilizing the chemicals within that drift out into the air to attract the insects. 所屬網頁 http://www.beals.us/pinebush 所屬網頁 http://www.kta.kh.edu.tw/

37. Overview: commensalism.Certainly, the looking-glass orchid benefits from the amorous travels of the male wasp, but the wasp receives no biological return. Similarly, the skunk cabbage benefits frominsect pollinators, but the insects fond no beneficial resource.Some biologists argue that these are not examples of commensalism (benefit/no harm), but of behavioral parasitism (benefit/harm)-only the plants gain in the interaction, the insects lose.

38. Initially, ancestors to skunk cabbages may have depended on all available insect pollinators. But skunk cabbages are physiologically adapted for life in wet and soggy places, dim light, and shade.The skunk cabbage only needs to a built- in attraction to some flies and beetles, in which it is a sensory delight already in place as part of their own reproductive quest.

39. Sometimes it pays to hide. Organisms that conceal themselves from enemies may do so with camouflage or cryptic coloration and shape.Rounded “stone plants” live in arid and open habitat, they are the shape of inedible stones, and silver skinned Many animals, like plants, looks like an uninteresting dry stem;only falls to the ground and continues the deception, remaining motionless Camouflage

40. Camouflage—inedible The resemblance of these insects to inedible plant parts affords them some protection from prowling insect-eating predators, such as birds.

41. Camouflage—coloration and shape • This dwarf seahorse (center) is camouflaged within the branches of this colonial sea fan. Reef, Solomon Islands.

42. Camouflage—arctic hare • This hare depends upon its white color to blend into the snowy background. When discovered, it turns to speed to make an escape from predators.

43. Harbor seal pup • The white coat of the harbor seal pup affords some camouflage with the ice and snow upon which it spends much of its early life when it is especially vulnerable to predators.

44. Camouflage—predator • This stonefish is encrusted with various creatures of the coral reef, camouflaging it to unsuspecting prey that cruise by.

45. Sometimes it pays toadvertise. Coloration that publicizes an organism’s presence is warning coloration or aposematic coloration.Arrow frogs of tropical South Americatoxic skinthe toxins must be ingested or enter the bloodstream, to be dangerousThe cooking denatures the frog toxins. 所屬網頁 http://www.oceanproaquatics.com/

46. Sometimes animals doboth-hide and advertise. The screech owl, tucks itself up against the tree, closes its headlight –like eyes;owl puffs up, spreads its wings, displays its bright eyes, and tries to look formidable. Venomous rattlesnakes remain silent, not move or rattle its tail.It turns into a flurry of display; warning behavior.

47. Sometimes it pays to startle.Eye spots occur in moths, on caterpillars, and even on the rumps of frogs.Namely, to startle the predator long enough to make an escape

48. Startle Response, Eyespots on Butterfly

49. Sometimes it pays to impersonate. The superficial resemblance between two or more organisms that results from a co-evolutionary relationship is termed mimicry.The term mimicry is usually applied in a strict sense to two general categories of mimicry: Batesian mimicry and Müllerian mimicry, each named for the first person to publicly recognize the type. MIMICRY

50. Mimicry II • a) Batesian mimicry between toxic monarch (model) and harmless viceroy (mimic), left and right, respectively. • b) An example of Müllerian mimicry, where both ecologically sympatric pairs are distasteful, and both have warning coloration.