440 likes | 564 Views
The Hong Kong University of Science and Technology. Department of Biology. http://www.ust.hk http://www.ust.hk/~webbo/. Presenters : Arthur Cheung (bo_cklab@stu.ust.hk Louis Shum (bo_sht@stu.ust.hk). What Is Adaptation?. Adaptation:
E N D
The Hong Kong University of Science and Technology Department of Biology http://www.ust.hk http://www.ust.hk/~webbo/ Presenters : Arthur Cheung (bo_cklab@stu.ust.hk Louis Shum (bo_sht@stu.ust.hk)
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) http://www.learninglive.co.uk/srb-projects/internet/pages/habitat%20adaptation/webpages/habitatindex.html
South Poles (南極) • Temperature: -40oC in average, can be as low as -57oC • Winds: up to 100 mph http://eosl.csl.uiuc.edu/home/images/SP/SouthPole_Station%5B1%5D.jpg http://www.mreclipse.com/Store/LM1/image/LM1-01w.JPG
Tropical Rain Forest (熱帶雨林) • Rainfall: 250-1000cm/ year • Temperature: ~35oC • Climate: Hot and wet http://www.blueplanetbiomes.org/rainforest.htm
Desert (沙漠) • Rainfall: <25cm/year • Temperature: >40oC in daytime • Climate: Hot and dry http://bama.ua.edu/~liu025/photo/China%20Phote/TengGeli%20Desert.JPG http://midsun.uwaterloo.ca/images/msvi/asc/Desert.jpg
Hydrothermal Vents (熱泉) • Temperature: 390oC • High hydrogen sulfide (H2S) and methane (CH4): food sources of some organisms • Geo-chemical energy http://statusreports-atp.nist.gov/reports/images/deep-sea.jpg
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:http://www.nationalgeographic.com/channel/highspeed/2004/08/20040823news.html?format=wm&vid=20040823ngppenguins.asf
Evolution of Penguins Phylogenetic Tree http://www.adelie.pwp.blueyonder.co.uk/Evolution/evolve.html
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: -40oC in average, can be as low as -57oC • 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)
Predation Penguins are preys of: • Leopard seals (海豹) • Killer whales (殺人鯨) • Sharks (鯊魚)
Leopard Seals http://www.dougallan.pwp.blueyonder.co.uk/picpops/images/lectures_da15.jpg
Killer Whales http://menua.aic.net/~vvk/seaa/orc/orca11.jpg
Sharks http://www.laups.org/cgray/images/blue.jpg http://seashadows.narod.ru/rus/images/im020.jpg
How Do Penguins Adapt to the Environment? http://www.adelie.pwp.blueyonder.co.uk/PhotoIndex/SPH_PICS.htm
Adaptation of Penguins (1) Morphological (形態上) (2) Physiological (生理上) (3) Behavioral (行為上)
(1) Morphological Adaptation • Feather • Bone • Different colors in dorsal and ventral parts of the body
Which Feather Belongs to Penguin? http://www.seaworld.org/infobooks/ Penguins/physical.html http://wings.avkids.com/Book/Animals/intermediate/birds-01.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? http://octopus.gma.org/surfing/antarctica/penguin.html http://www.adelie.pwp.blueyonder.co.uk/anatomon.htm http://192.107.108.56/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 http://www.biology.ualberta.ca/courses.hp/bio366/Image71.jpg
Mechanism of Diving http://www.bio.davidson.edu/people/midorcas/animalphysiology/websites/2004/Gooch/index.htm http://www.biology.ualberta.ca/courses.hp/bio366/Image71.jpg
Mechanism of Diving The most important mechanism involved in diving is oxygen saving. • Reduced heart rate • Change in blood flow (by-passing) and reduced sensitivity to CO2
Reduced Heart Rate http://www.bio.davidson.edu/people/midorcas/animalphysiology/websites/2004/Gooch/oxygen.htm#adl
Change in Blood Flow and Reduced Sensitivity to CO2 • Increased oxygen supply to skeletal muscle • Reduced blood flow to brain, heart and lungs • Prevent termination of breathing • Reduce receptors’ sensitivity in brain to CO2
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 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? http://www.aad.gov.au/default.asp?casid=3524
Huddling • Density: 10 individuals per m2 • Reduces heat loss up to 50% • Temperature inside the huddle can be as high as 35oC • 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 http://englishnf.pinguins.info/
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 http://www.antarcticconnection.com/antarctic/wildlife/penguins/adelie.shtml Penguins’ call
Sharing Parental Duties • 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 http://www.aad.gov.au/default.asp?casid=3524 http://www.aad.gov.au/default.asp?casid=3524
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 • Akwarium Gdynskie, http://www.aad.gov.au/default.asp?casid=3524 • Animal, http://wings.avkids.com/Book/Animals/intermediate/birds-01.html • Animal explore discover connect, http://www.seaworld.org/infobooks/Penguins/physical.html • Animal diversity web, http://animaldiversity.ummz.umich.edu/site/accounts/information/Sphenisciformes.html • Antarctic connection, http://www.antarcticconnection.com/antarctic/wildlife/penguins/adelie.shtml • Australian Antarctic Division, http://www.aad.gov.au/default.asp?casid=3524 • BBC weather center, http://www.bbc.co.uk/weather/features/weatherbasics/zones_desert.shtml • Boreal Ecology, http://www.biology.ualberta.ca/courses.hp/bio366/Image71.jpg • Charles Darwin, The Origin of species, Modern Library. P.108-117 • Diving mechanism in Penguins, http://www.bio.davidson.edu/people/midorcas/animalphysiology/websites/2004/Gooch/oxygen.htm#adl
Major References • 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. 2004 Jul 16;279(29):30433-9 • Paul and Bernice Noll's Window on the World, http://www.paulnoll.com/Oregon/Birds/Avian-Skeleton.html • Penguins around the world, http://www.siec.k12.in.us/~west/proj/penguins/species.html • Pete & Barb’s Penguin Pages, http://www.adelie.pwp.blueyonder.co.uk/anatomon.htm • 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, 101-107 (2002) • Sugiarto H., Yu PL (2004), Avian antimicrobial peptides: the defense role of β-defensins. Biochemical and Biophysical Research Communication 323 (2004) 721-727 • Tropical Rain forest, http://www.blueplanetbiomes.org/rainforest.htm • The climate of tropical rain forest, http://www.cdli.ca/CITE/rainforest_climate_students.htm • Wikipedia, http://en.wikipedia.org/wiki/Ecological_selection • World Habitat, http://www.learninglive.co.uk/srb-projects/internet/pages/habitat%20adaptation/webpages/habitatindex.html
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.