the morphological evolution and geographic distribution of spheniscus penguins ashley drexel &...
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The Morphological Evolution and Geographic Distribution of Spheniscus
penguins
Ashley Drexel & Claire Patterson
Basic Penguin Characteristics
Flightless Strong paddle-like wings for propulsion
Counter-shaded Dark on dorsal surface, white on
ventral Varying patterns among
speciesLarge head, short neck, &
elongated body adapted for swimming
Salt excreting glands
Emperor (Aptenodytes)
Fairy (Eudyptula)
Why are they flightless?
Wing support Weight to wing area ratio
Food availability Readily available food in
marine and terrestrial environments resulting in no need for extensive flights for search for food.
As a result, natural selection played a significant role in making them flightless.
Alternative function Water propulsion by
flippers
Smithsonian 2010
Geographic Distribution
Living species are classified in six clearly defined genera: Antarctica/cool temperate waters
Aptenodytes Eudyptes Pygoscelis
New Zealand Megadyptes
Australia/New Zealand Eudyptula
South America, Southern Africa, & the Galapagos Islands Spheniscus
Geographic Origin
Post continental drift As a result of continental drift, two land masses were
formed from Pangea: Gondwana and Laurasia Gondwana contained modern day South America,
Africa, Antarctica, India and Australia Location of modern day penguins’ roots
Phylogenetic Origin
Order Procellariformes Oldest fossilized penguin found dates back to 60
million years ago Records show clear evidence that penguins evolved
from a flying ancestor
Family: Spheniscidae
Spheniscus magellanicus (Magelllanic)
Spheniscus demersus (Jackass/African)
Spheniscus humboldti (Peruvian)
Spheniscus mendiculus (Galapagos)
Spheniscus Species
Nest Eggs
Twigs seaweed, roots 2 greenish eggs
Young Incubation
2 38-41 days
Height Weight
63cm,25in 2.1-4.9 Kg
Home Season
Coastal Southern Africa Nov-Mar
Jackass, African (Spheniscus demersus) Nest Eggs
Caves and crevices and burrows in sand 2 eggs
Young Incubation2 About 40 days
Height Weight68cm, 27in 4.1-5.8 Kg
Home SeasonWest Coast South
America All year
Peruvian (Spheniscus humboldti)
Nest EggsA burrow up to 3m
(10ft) deep Pebbles, twigs, leaves,
etc
2 white eggs
Young Incubation2 About 28 days
Height Weight70cm, 28in 4.9-7.9 Kg
Home SeasonFalkland Islands and
Coastal Patagonia Oct
Magellanic (Spheniscus magellanicus)
Nest Eggs
A few stones 2 white eggs
Young Incubation2 38-40 days
Height Weight50cm, 20in 1.7-2.8 Kg
Home Season
Galapagos Islands All Year
Galapagos (Spheniscus mendiculus)
Where Are They Now?
ga (Galapagos Islands) Spheniscus mendiculus
saf (South Africa) Spheniscus demersus
sam (South America) Spheniscus magellanicus, Spheniscus humboldti
ga
sam
saf
How has the evolution of Spheniscus penguins’ morphology changed to help them survive in warmer
climates?
Featherless patches surrounding head
Feather erectors Autonomic regulation Air pockets between
feathers and skin act as insulators as in fiber glass insulation in the attic of your house
Air sacs Excellent Insulator
Fatty layer under the skin
How has the evolution of Spheniscus penguins’ morphology changed to help them survive in warmer
climates?....(continued)
Body size More surface area
warmer the climate Less surface area cooler
the climate Metabolism
Penguins are like us Homeotherms
Lowers body temperature to reduce heat loss when entering water
Smithsonian 2010
Spheniscus Morphology
Works Cited
Raikow, Robert J., Lesley Bicanovsky, and Anthony H. Bledsoe. “Forelimb Joint Mobility and the Evolution of Wing-Propelled Diving in Birds”. The Auk. July 1988: Vol 105, 446-451.
Baker, Allan J.. "Multiple gene evidence for expansion of extant penguins out of Antarctica due to global cooling". Proceedings of the Royal Society October 2005: Vol 273, 11-17.
Olson, Storrs. "Fossil Counterparts of Giant Penguins from the North Pacific". Science November 1979: Vol 206, 688-689.
Croxall, J.P.. "Penguins: Paradoxes and Patterns". Marine Onithology 1999: Vol 27, 1-12.
Grant, Stewart W.. "Allozyme Phylogeny of Sphenicus Penguins". The Auk 1994: 716-720.
Bertelli, Sara, Noberto P. Giannini. "A phylogeny of extant penguins (Aves: Sphenisciformes) combining morphology and mitochondrial sequences". Cladistics 2005: 209-239.
http://tuxxie.org/evolution/fossil-penguins.html http://earthguide.ucsd.edu/penguins/
QUESTIONS?????