Presentation on theme: "Presenters : Arthur Cheung Louis Shum Louis Shum The Hong Kong University of Science and Technology."— Presentation transcript:
Presenters : Arthur Cheung Louis Shum Louis Shum The Hong Kong University of Science and Technology Department of Biology
What Is Adaptation? Adaptation: An inherited trait or set of traits that increases the chances of survival and reproduction of an organism in a particular environment. In different habitats, each species has its own set of characters for survival.
What Is Adaptation? Natural Selection = Survival of the fittest + Selective Pressure (Charles Darwin, Origin of Species, 1859) Sexual selection ( 性選擇 ) Ecological selection ( 生態選擇 )
Harsh Habitats in Our Biosphere South Poles ( 南極 ) Tropical Rain Forest ( 熱帶雨林 ) Desert ( 沙漠 ) Hydrothermal Vent ( 熱泉 ) projects/internet/pages/habitat%20adaptation/webpages/habitatindex.html
South Poles ( 南極 ) Temperature: -40 o C in average, can be as low as -57 o C Winds: up to 100 mph Station%5B1%5D.jpg 01w.JPG
Tropical Rain Forest ( 熱帶雨林 ) Rainfall: cm/ year Temperature: ~35 o C Climate: Hot and wet nforest.htm
Desert ( 沙漠 ) Rainfall: <25cm/year Temperature: >40 o C in daytime Climate: Hot and dry Phote/TengGeli%20Desert.JPG /asc/Desert.jpg
Hydrothermal Vents ( 熱泉 ) Hydrothermal Vents ( 熱泉 ) Temperature: 390 o C High hydrogen sulfide (H 2 S) and methane (CH 4 ): food sources of some organisms Geo-chemical energy
Case Study: Penguin ( 企鵝 ) Reasons for choosing this model: Can be found in extreme environments (e.g. South Pole) and in other habitats (e.g. South Africa) Penguins in different habitats have different adaptation characteristics Video: hspeed/2004/08/ news.html?format=w m&vid= ngppenguins.asf hspeed/2004/08/ news.html?format=w m&vid= ngppenguins.asf
Evolution of Penguins Phylogenetic Tree
What Problems Do Penguins Face? - Abiotic Factors ( 非生物性因素 ) - Biotic Factors ( 生物性因素 )
Abiotic Factors ( 非生物性因素 ) Non-living factors affecting the life of organisms –Light –Temperature –Atmospheric gases South Pole: Temperature: -40 o C in average, can be as low as -57 o C Winds: Strong winds up to 100 mph
Biotic Factors ( 生物性因素 ) Environmental influences resulting from the activities of living organisms –Competition ( 競爭 ) Interspecific competition ( 種間競爭 ) Intraspecific competition( 種內競爭 ) –Predation ( 捕食 )
(1) Morphological Adaptation Feather Bone Different colors in dorsal and ventral parts of the body
Which Feather Belongs to Penguin? rmediate/birds-01.html Penguins/physical.html
Feather 4 layers of feathers Shiny feathers uniformly overlap to cover the skin Highly specialized: short, broad, and closely spaced Tufts of down on the feather shafts: insulation ( 隔熱 )
Which Skeleton Design Makes Penguin a Good Diver? rfing/antarctica/penguin.h tml wp.blueyonder.co.u k/anatomon.htm 6/portfolios/h/harris _d/final/sectns.htm
Different Colors in Dorsal and Ventral Parts Ventral part( 腹部 ): White Dorsal part ( 背部 ): Black Why different colors in dorsal and ventral parts?
(2) Physiological Adaptation Characteristics unique in South Pole species: Recycle of body heat Mechanism of diving Preservation of food
Recycle of Body Heat
Mechanism of Diving ourses.hp/bio366/Image71.jpg orcas/animalphysiology/websites/2004/G ooch/index.htm
The most important mechanism involved in diving is oxygen saving. Reduced heart rate Change in blood flow (by-passing) and reduced sensitivity to CO 2 Mechanism of Diving
Reduced Heart Rate /oxygen.htm#adl
Change in Blood Flow and Reduced Sensitivity to CO 2 Increased oxygen supply to skeletal muscle Reduced blood flow to brain, heart and lungs Prevent termination of breathing –Reduce receptors’ sensitivity in brain to CO 2
Preservation of Food Proteins in stomach for preservation of food Antimicrobial peptides –Example: β-defensins (Sugiarto et al., 2004 ) Spheniscins (Landon et al., 2004) –Work with other antimicrobial peptides –Preserve food for several weeks during incubation of eggs
(3) BehavioralAdaptation (3) Behavioral Adaptation Characteristics unique in South Pole species: Huddling Drawing neck and flipper tightly against the body Sharing parental duties
Why Do Penguins Form Colonies in Winters?
Huddling Density: 10 individuals per m 2 Reduces heat loss up to 50% –Temperature inside the huddle can be as high as 35 o C Prolongs fat storage
Huddling In windy days, individuals at the edge are exposed to the wind and therefore have a higher rate of heat loss. They shift from edge to center to keep their bodies warm. They move together with their chicks.
Neck and Flipper Drawn Tightly against Body Why do penguins always draw their neck and flipper tightly against the body? –Minimize surface area contact with the surrounding –Reduce heat loss
Sharing Parental Duties Emperor Penguins (Aptenodytes forsteri) incubate eggs without eating for 65 days Females search for food and help in incubation –How can females find their partners? They recognize their partners by voice delie.shtml Penguins’ call
Parents can stop eating in turn for more than 3 months to take care of the chicks Feeding chicks with fish and squid by regurgitation Sharing Parental Duties
Summary Purpose of adaptation: Increases the chances of survival and reproduction of an organism in a particular environment. Forms of adaptation: Morphological, physiological, behavioral Case study: Penguins – Characteristics found in South Pole species different from those in South Africa
Major References 1.Akwarium Gdynskie, 2.Animal, 3.Animal explore discover connect, 4.Animal diversity web, mes.html mes.html 5.Antarctic connection, 6.Australian Antarctic Division, 7.BBC weather center, 8.Boreal Ecology, 9.Charles Darwin, The Origin of species, Modern Library. P Diving mechanism in Penguins, Gooch/oxygen.htm#adl Gooch/oxygen.htm#adl
Major References 11.Landon C, Thouzeau C, Labbe H, Bulet P, Vovelle F (2004). Solution structure of spheniscin, a beta-defensin from the penguin stomach. J Biol Chem Jul 16;279(29): Paul and Bernice Noll's Window on the World, 13.Penguins around the world, 14.Pete & Barb’s Penguin Pages, 15.Rezende EL, Swanson DL, Novoa FF, Bozinovic F (2001) Passerines versus nonpasserines: so far, no statistical differences in the scaling of avian energetics. The journal of Experimental Biology 205, (2002) 16.Sugiarto H., Yu PL (2004), Avian antimicrobial peptides: the defense role of β- defensins. Biochemical and Biophysical Research Communication 323 (2004) Tropical Rain forest, 18.The climate of tropical rain forest, 19.Wikipedia, 20.World Habitat, projects/internet/pages/habitat%20adaptation/webpages/habitatindex.htmlhttp://www.learninglive.co.uk/srb- projects/internet/pages/habitat%20adaptation/webpages/habitatindex.html
Enjoy the nature
Acknowledgements Prof. K.L. CHOW Prof. Philip I.K. SOU Prof. Michael K.Y. WONG Dr. T.K. GOH Dr. Maggie LI Dr. Ice KO Dr. Y.Y. REN Mr. Wilfred LEUNG Mr. Jack LI Center for Enhanced Learning and Teaching This project is funded by the Center for Enhanced Learning and Teaching of HKUST.
Preservation of Food: Spheniscins 38 amino acids Work together with other antimicrobial substances in the stomach for preservation of food Inhibit growth of or kill the microbes 3D structure of Spheniscins gi?form=6&db=t&Dopt=s&uid=27989
Sexual Selection The most successful individuals pass their genetic materials to their offspring. The less successful individuals’ genes are eliminated and they cannot pass their genes to the next generation. “…It depends, not on a struggle for existence in relation to other organic beings or to external conditions, but on a struggle between the individuals of one sex…” “The result is not death to the unsuccessful competitor, but few or no off-spring” “The most vigorous males. Those which are best fitted for their places in nature” Origin of species, Charles Darwin
Ecological Selection Strictly ecological processes that operate on a species' inherited traits without reference to mating or secondary sex characteristics Inheritance of specific traits is determined by ecology alone without direct sexual competition, when e.g. sexual competition is strictly ecological or economic, there is little or no mate choice, females do not resist any male who wishes to mate, all traits will be equally propagated regardless of mating, or the species is hermaphroditic or asexually reproduction, an ecological selection is taking place. Example: Giant panda. (http://en.wikipedia.org/wiki/Ecological_selection, Wikipedia)http://en.wikipedia.org/wiki/Ecological_selection