21-Lecture_True

21-Lecture_True - Biology in the News[see folder on BB the...

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Unformatted text preview: Biology in the News [see folder on BB] the greenhouse effect is leading to warming that is predicted to cause a major climate change in the northwestern North America, which is the North American habitat of the Gulo gulo (also occurs throughout far North Asia) •  wolverines live in tundra and boreal forest •  The wolverine needs snow cover in the spring for raising their offspring •  springBme dens are made in snow for protecBon and warmth •  and it needs summers not to get too hot for it to tolerate •  both of the above condiBons are predicted to disappear, threatening the species in large parts of its current range •  The likelihood that wolverines will sBll survive anywhere in the lower 48 states is thought to be low, based on recent climate change predicBons •  current populaBon in Canada is esBmated at 15,000, in US only dozens to a few hundred are thought to exist •  in a mathemaBcal model, various climate condiBons were tested to see whether spring snow cover and summer temperatures were sBll permissive for wolverines; only a scenario in which carbon emissions were substanBally lowered leO the habitats unchanged from their current state •  hPp://www.nsf.gov/news/news_summ.jsp? cntn_id=118543&WT.mc_id=USNSF_51&WT.mc_ ev=click nd mid term exam 2 •  •  •  •  •  •  •  •  Wed. October 26th in class covers material from Mon. 26‐Sept. through Fri. 21‐Oct. (10 lectures) pracBce quesBons are posted; review sessions – next slide Be on Bme –  >10 min late will not be allowed into room Bring only your ID and pencils –  All other materials have to be leO on periphery of the room 35 mulBple choice quesBons + 3 bonus bio news quesBons lowest of the three mid terms is dropped, avg. of other 2 = 60% of your grade Only documented medical/family/accident excuses accepted •  we need to be NOTIFIED before end of the day on the day of the exam review sessions for 2nd mid term exam •  •  •  •  •  •  •  Alvin ‐ Monday ‐ 10:00 ‐ 11:00 Safa ‐ Monday 2:00 ‐ 3:00 Harrison ‐ Monday ‐ 4:00 ‐ 5:00 Redwan ‐ Tuesday ‐ 9:00 ‐ 10:00 Dana ‐ Tuesday ‐ 2:30 ‐ 3:30 Dana ‐ Wednesday ‐ 10:00 ‐ 11:00 all are in Life Sciences 026 – Bring Your QuesBons! Bird skeletal adaptaBons for flight •  furcula (i.e. the “wishbone”) –  consists of the two clavicles (collar bones) fused together •  along with keeled sternum and large pectoral (breast) muscles provides strength for flight movements Bird respiratory system – adapted for flight metabolism •  Birds breathe using small lungs –  also have 9 air sacs •  Air sacs do not exchange gases with blood; they store oxygenated air –  act as bellows, pushing fresh air into the lungs •  Mammals: O2 rich air in, O2 poor air out – rich and poor air mixed in lungs •  Birds: constant (unidirecBonal) flow of O2 rich air through lungs: more efficient –  only O2 rich air contacts blood vessels –  Take fewer breathes •  Also: Bird hemoglobin holds more oxygen than mammalian hemoglobin hPp://www.peteducaBon.com/ arBcle.cfm?c=15+1829&aid=2721 A current view of bird phylogeny Order Passeriformes (Passerine birds); “perching” birds; >half of all bird species. includes sparrows, crows, ravens, jays, warblers, nuthatches starlings, thrushes, wrens, finches, many other groups hPp://www.thewildclassroom.com/ biodiversity/birds/aviantopics/ birdsystemaBcs.html Paleognathae and Neoghathae are disBnguished by structural differences in the skull and ankle According to this hypothesis, two major predator groups (“birds of prey”) evolved independently Ratites (order Struthioniformes) one group of Paleoghathae kiwi ostrich rhea cassowary Haast's Eagle aPacking New Zealand moa Both species went exBnct ~1400 aOer human sePlers arrived. ‘REPTILES’ turtles tuataras mammals amphibians ? Ancestral amniote lizards & snakes crocodilians birds Features of mammals •  endothermic •  four‐chambered heart with single aorBc arch –  independently evolved from birds •  •  •  •  •  diaphragm hair mammary glands sweat glands secondary palate –  enables suckling hPp://www.nasmus.co.za/PALAEO/jbotha/Images/dog%20palate3.jpg Thoracic Diaphragm •  Unique to mammals –  some repBles (e.g. crocodiles) and amphibians have diaphragm‐like structures –  most repBles use throat, rib movements or other muscles for breathing –  birds: no diaphragm •  coordinated movements of most of the body act to venBlate lungs •  Band of muscle across boPom of ribcage separaBng chest from abdomen •  Crucial for breathing –  Contracts during inhalaBon to expand thoracic cavity –  Relaxes to allow exhalaBon hPp://en.wikipedia.org/wiki/Thoracic_diaphragm The glands of mammals •  •  •  •  •  All appear to be evolved from a common ancestral gland formed from epithelial (ectoderm) cells Controlled by the nervous system and hormones Sweat glands: two kinds –  Apocrine ‐ secrete into hair follicles •  Armpit, groin, nipple areas •  Secrete a viscous substance beginning at puberty; Sebaceous may contain substances acBng as pheromones in gland Sweat gland humans Hair follicle –  Merocrine (also called “eccrine”) ‐ far more numerous hPp://www.sweathelp.org/English/ PFF_Hyperhidrosis_Overview.asp and widespread on body (~3 million in adult human) ‐ secrete sweat Mammary glands and ceruminous glands (secrete ear wax) are evoluBonarily modified sweat glands Sebaceous glands –  Secrete sebum: waxy substance containing fat and cellular debris –  In rats and mice, these have been evoluBonarily modified into prepiBal glands which produce pheromones epidermis dermis hair •  90% of cells in epidermis are keraBnocytes hPp://www.infovisual.info/03/037_en.html –  Produce keraBn in skin –  Fish, repBles, birds, also have keraBnocytes •  Melanocytes in epidermis produce melanin and export melanosomes to developing hair and skin –  Originate from neural crest in embryo –  Migrate into epidermis during development hPp://www.ratbehavior.org/images/Melanocyte.jpg Skeletal features of mammals hPp://www.infovisual.info/02/070_en.html •  limbs verBcally below body •  more sacral vertebrae •  reduced pectoral girdle •  no lumbar ribs Features of mammal skull •  reducBon and fusion of some skull bones •  secondary palate (see previous slide) •  enlarged brain case with verBcal walls •  greatly enlarged postorbital opening (single opening) •  differenBated teeth •  lower jaw is a single bone (dentary) •  three middle ear bones (repBles have one) A current view of mammal evoluBon Blue = name of an order Red = name of a superorder Monotremes (echidna, platypus) Marsupials tenrecs, golden moles, elephant shrews Xenarthra (anteaters, sloths, armadillos) Carnivora, CetarBodactyla, Perissodactyla, Chiroptera, hedgehogs, shrews, moles, pangolins Rodents, lagomorphs, primates A current view of mammal evoluBon Monotremes (echidna, platypus) PROTHERIANS Marsupials Carnivora, CetarBodactyla, Perissodactyla, Chiroptera, hedgehogs, shrews, moles, pangolins Rodents, lagomorphs, primates CetarBodactyla = cetaceans plus arBodactyls = even toed ungulates (e.g. camels, pigs, hippos, cows) + exBnct groups Perissodactyla = horses, tapirs, rhinos + exBnct groups EUTHERIANS Xenarthra (anteaters, sloths, armadillos) THERIANS tenrecs, golden moles, elephant shrews Eutherian mammals •  SomeBmes called “placental mammals” –  But this is not accurate, marsupials also have placentas •  Placenta: temporary Bssue produced from fetal cells, used for respiratory and nutriBonal exchange with the mother –  Eutherians are born more developed than marsupials –  Eutherians do not have the pouches of marsupials Baby wombat ArcBc wolf pup Convergence in placental and marsupial mammals http://www.britannica.com Common ancestor: 100‐150 mya A current view of mammal evoluBon Monotremes (echidna, platypus) PROTHERIANS Marsupials Carnivora, CetarBodactyla, Perissodactyla, Chiroptera, hedgehogs, shrews, moles, pangolins Rodents, lagomorphs, primates EUTHERIANS Xenarthra (anteaters, sloths, armadillos) THERIANS tenrecs, golden moles, elephant shrews (a taxonomic order) Galago Tarsier Proboscis Monkey Old world vs. new world monkeys (formally disBnguished by various facial and dental traits) •  Old world monkeys –  Found in Africa and Asia •  One species in Europe (Gibraltar) –  Most have tails, but their tails are not prehensile •  New world monkeys –  Found in Central and South America –  Tails are prehensile •  Used for grasping or aiding movement, stability Howler monkey olive baboon hPp://flickr.com/photos/ [email protected]/234740 0431 superfamily Hominoidea “the Lesser apes” (Gibbons) 4 genera 33 species (2 species) family Hominidae; “the Great Apes” Some confusing jargon to keep track of •  Hominid ‐ species in the family Hominidae; “the Great Apes” •  Hominin ‐ refers to members of the tribe Hominini; chimps and humans •  Hominoid ‐ refers to members of the superfamily Hominoidea; “lesser apes” (Gibbons) + “great apes” The fossil record of hominins Genera: H. = Homo Au. = Australopithecus P = Paranthropus K. = Kenyanthropus Ar. = Ardipithecus S. = Sahelanthropus O. = Orrorin Stone tools Lucy Africa Asia Europe Australopithecus •  genus of hominids •  arose in Africa ~4 mya, went exBnct ~2 mya •  4‐4.5 O tall, brain size about 1/3 of modern human •  thought to be mostly vegetarian, frugivorous hPp://en.wikipedia.org/wiki/Australopithecus Paranthropus •  “robust australopithicines” –  formerly placed in genus Australopithecus •  4.2 – 4.6 O in height –  brain size ~40% of modern human hPp://en.wikipedia.org/wiki/Paranthropus Homo floresiensis •  •  •  •  •  •  •  •  •  •  •  discovered in Flores, Indonesia in 2004 parBal skeletons of 9 individuals have been found; including a complete skull very small body and brain may have lived as recently as 12,000 years ago (found in sediments 94,000 ‐ 13,000) ya found with stone tools Are they Homo sapiens or a different species? Studies of wrist, arm, shoulder morphology found more similariBes to early humans and apes than to modern humans; support separate species status brains the size of chimps or some Australopithecus; brain‐to‐body raBo is about the same as H. erectus dorsalmedial prefrontal cortext (Brodmann's area 10) involved in self‐awareness, about the same size as modern human "insular dwarfism"? H. sapiens with microcaphaly disease? (recent studies seem to suggest against) hPp://www.theage.com.au/ffximage/2005/03/18/ evoluBon_1903_wideweb__430x328,1.jpg Homo neanderthalensis •  •  •  •  •  •  •  •  •  •  •  •  also has been classified as a subspecies: H. sapiens neanderthalensis morphological features 350K to 600K ya appeared in Europe complete Neanderthal features present at 130K ya in Europe features disappeared in Asia by 50k ya DNA evidence suggests interbreeding with modern humans between 80k and 50k ya est. 1‐4% of Eurasian human genomes may be from Neaderthals disappeared ~30k ya (CroaBa); evidence of Neanderthal in Gibraltar 24k YA used stone tools brains about same size as modern humans may have been omnivores what happened to them? we are likely part Neanderthal (?) hPp://en.wikipedia.org/wiki/ File:Kermanshah_Pal_Museum‐Neanderthal.jpg concerning... •  my office hours the rest of the semester – call or e‐mail ahead •  recommendaBon lePers – a lePer from me based on this course alone, even if you got an A, is not very useful and might even reflect poorly on your applicaBon see if you can draw the tree of life from memory ...
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This note was uploaded on 12/16/2011 for the course BIO 201 taught by Professor True during the Fall '08 term at SUNY Stony Brook.

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