1. The Morphological Evolution and Geographic Distribution of Spheniscus penguins
Ashley Drexel & Claire Patterson

2. Basic Penguin Characteristics
Flightless
Strong paddle-like wings for propulsion
Counter-shaded
Dark on dorsal surface, white on
ventral
Varying patterns among
species
Large head, short neck, &
elongated body adapted for
swimming
Salt excreting glands
Counter-Shaded:
The dark dorsal side blends in with the dark ocean depths when viewed from above. The light ventral side blends in with the lighter surface of the sea when viewed from below. The result is that predators or prey do not see a contrast between the counter-shaded penguin and the environment.
All species have different markings that distinguish them from others
Chicks, juveniles, and immature penguins may have slightly different markings than adults. Generally, they appear duller in color than adults. Adult markings take a year or longer to develop.
Anatomy:
A penguin has a large head, short neck, and elongated body. The penguin's body is adapted for swimming.
The tail is short and wedge-shaped.
Penguin legs are short and strong. Feet are webbed, with visible claws
Head, Bill, and Eyes vary among different species.
Each flipper is covered with short, scale-like feathers.
**interesting find: penguins have knees!
Salt excreting glands:
Feed on organisms in the water, and drink sea water. Glands are specialized to filter out the salt.
Size:
The emperor penguin is the largest of all living penguins, standing 1.1 m (3.7 ft.) and weighing 27 to 41 kg (60-90 lb.). (aptenodytes - ap-ten-uh-DIE-teez)
The smallest of the penguins is the fairy penguin, standing just 41 cm (16 in.) and weighing about 1 kg (2.2 lb.).
Sexual dimorphism:
• Generally, penguins are not sexually dimorphic: males and females look alike. Crested penguins are exceptions: the males are more robust and have larger bills than females.
Emperor (Aptenodytes)
Fairy (Eudyptula)

3. 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
Wings are modified into paddle-like flippers. The bones are flattened and broadened, with the joint of the elbow and wrist almost fused. This forms a tapered (gradually narrower), flat flipper for swimming.
Smithsonian 2010

4. 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
Aptenodytes  Emperor & King penguins
Eudyptes  6 species of crested penguins
Pygoscelis  3 species of pygoscelid
Megadyptes  Yellow-eyed penguin
Eudyptula  Little blue & White-flippered penguins
Spheniscus  4 species Spheniscid penguins

5. 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

6. 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
1st figure: Notice that Spheniscidae stem from the Procellariformes (pro-sell-ar-eye-uh-FORM-eez) which stem from the Pelecaniformes (pel-uh-kan-uh-FORM-eez) which obviously containing pelicans.
So, you can see that the auks, which are often mistaken as being closely related to the penguin due to their similar size, shape and ecological niche, aren't closely related to penguins at all. However, you can see what are closely related to penguins: the Procellariformes from which penguins descend directly, and the Graviidae, which is a daughter clade of the Procellariformes with the Spheniscidae.
2nd figure: According to a study by Baker, penguins date back when Aptenodytes diverged as the bottom, basal, lineage.
Then around 38 mya the Pygoscelis lineage branched off, and later diversified into the adelie, chinstrap, and gentoo penguin.
Then followed the split between the Eudyptula and Spheniscus around 25 mya.
** Speciation within Spheniscus is recent (dating back to about 4 mya)
** The little blue & white-flippered penguins (Eudyptula) date back to about 2.7 mya.
Lastly, the Megadyptes (yellow-eyed penguin) diverged from Eudyptes about 15 mya.
** Snares crested and royal penguin diverged within last 2 mil yrs.

7. Family: Spheniscidae
This is illustrating the relationships among all the genera in family spheniscidae (sfen-IS-kuh-dee)

8. Spheniscus demersus (Jackass/African)
Spheniscus humboldti (Peruvian)
Spheniscus magellanicus (Magelllanic)
Spheniscus mendiculus (Galapagos)
These are the only four remaining species of Spheniscus that are still living today, as some have gone extinct
Some distinct characteristics of each species is as follows:
1) Demersus – African, black-footed, and/or "Jack-ass penguins" due to their loud locator calls sounding similar to a donkey.
Pattern: African penguins have a broad band of black that is in the shape of an upside-down horseshoe on their fronts. There have black spots scattered over their chest area.
Fact: Due to major oil spills in the habitats, rescue services have established new breeding colonies of the African penguins in the area.
: start at 1:13 end at 1:25
2) Magellanic - This penguin was named after Ferdinand Magellan who first saw them in 1519 on his first voyage around the tip of South America. Magellanic penguin is the largest of the warm-weather penguins.
Pattern: They have a wide black strip under their chin and another is in the shape of an upside down horseshoe on their stomachs. On their chests they have scattered black spots.
Fact: During the warm weather of the breeding season they lose the feathers around their eyes.
3) Mendiculus – Known as Galapagos penguin. This is the smallest of the warm weather penguins. It is the only penguin to cross the Northern Hemisphere which means they live farther north than any other warm weather penguin.
Pattern: Thin white band that runs under their chin. They have a black upside down horseshoe shape around their belly. Black markings on the belly are thinner than the Magellanic.
Fact: Due to extreme heat, there are several ways they keep themselves cool:
1) Swim & hunt for food in the cold water of the Cromwell Current during the day.
2) During the cool nights they sleep and nest on the land.
3) They hold their flippers out to help the heat escape their bodies.
4) Hold flippers over feet to protect themselves from sunburn
4) Humboldti - The Humboldt penguin is often called the Peruvian penguin. The name Humboldt came from the early European explorer that first saw these animals.
Pattern: Have a thick black upside down horseshoe shape on their belly. They look like the African penguin, but are shorter with longer flippers.
Fact: Within the last 100 years their droppings have been used as fertilizer. These droppings are called "guano". Mining the guano has caused serious damage to their habitats. Today the Humboldt penguin is endangered. There are as few as 10,000 birds in the wild today.
Spheniscus demersus (Jackass/African)

9. Spheniscus Species Jackass, African (Spheniscus demersus)
Peruvian (Spheniscus humboldti)
Nest
Eggs
Twigs seaweed, roots
2 greenish eggs
Young
Incubation 2
38-41 days
Height
Weight
63cm,25in Kg
Home
Season
Coastal Southern Africa
Nov-Mar
Nest
Eggs
Caves and crevices and burrows in sand
2 eggs
Young
Incubation 2
About 40 days
Height
Weight
68cm, 27in Kg
Home
Season
West Coast South America
All year
Magellanic (Spheniscus magellanicus)
Galapagos (Spheniscus mendiculus)
Nest
Eggs
A burrow up to 3m (10ft) deep Pebbles, twigs, leaves, etc
2 white eggs
Young
Incubation 2
About 28 days
Height
Weight
70cm, 28in Kg
Home
Season
Falkland Islands and Coastal Patagonia
Oct
Nest
Eggs
A few stones
2 white eggs
Young
Incubation 2
38-40 days
Height
Weight
50cm, 20in Kg
Home
Season
Galapagos Islands
All Year
Here’s a table that shows the reproductive cycle & characteristics of each species. Few things to note: they all produce 2 young & incubation period lasts about the same, however, their breeding season vary. They each construct different nests, and the African penguin is the only one of this genus to produce green eggs.
Molting: Most penguin species go through one complete molt (shed their feathers) each year, usually after the breeding season. The exception is the Galapagos penguin, which usually goes through two-three molts annually. The average length of the molt varies. For example it can be from 13 days for the Galapagos penguin to 34 for the emperor penguin. During the molt, feathers lose some of their insulating and waterproofing capabilities, and penguins stay out of the water until their plumage is restored to optimum condition.

10. Where Are They Now? ga (Galapagos Islands) Spheniscus mendiculus
saf (South Africa) Spheniscus demersus
sam (South America) Spheniscus magellanicus, Spheniscus humboldti
sam
saf
This globe demonstrates the breeding distribution among all the penguin species. Since we only focused on the extant Spheniscus species, you can see the galapagos penguins and the african penguin are isolated and only breed within their species. The penguins located in SA, S. magellanicus & S. humboldti, are among a few other species in two other genera (Eudyptes and Pygoscelis), however, they do not interbreed.
Just in case someone needs a more detailed description of how the Spheniscus species relocated to where they are today.
According to our study, here is one interpretation:
An Australian ancestor (az) which is in genus Eudyptula dispersed to South America (sam)
Then vicariance (seperation of organisms by geographic barrier, i.e. body of water) occurred and the lineage differentiated into Spheniscus in South America and Eudyptula in the Australia–New Zealand region.
Given that no Indian or Atlantic Ocean ranges were reconstructed, the likely dispersal route was trans-Pacific (meaning crossing the Pacific Ocean).
From South America, an ancestral Spheniscus form reached Africa, and the African descendant was followed by S. demersus (by trans-Pacific, since this was taking place millions of years ago)
A comparable event can be hypothesized for the Galapagos penguin: A South American ancestor reached the Galapagos Islands (ga)
Then a vicariance event produced the sister species S.mendiculus in Galapagos and S. humboldti in the Pacific South American coast.

11. 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
Featherless Patches: In the featherless regions surrounding the head/bills, air cannot be trapped so heat is given off rapidly at this point. The penguins emit heat to stay cool in the hot climates. Shiny feathers uniformly overlap to cover a penguin's skin. Penguin feathers are highly specialized - short, broad, and closely spaced. This helps keep water away from the skin. Tufts of down on the feather shafts increase the insulative properties of the feathers.
Feather Erectors: In areas where there are feathers, penguins contract muscles called feather erectors which cause their feathers to become erect. This eliminates a good deal of the covered insulation feathers supply and allows heat to exchange with the atmosphere. These mechanisms allow the penguin too cool down. Furthermore, they are under autonomic regulation -- that is, the penguin does this involuntarily.
Air Sacs: Additionally, the penguin air sacs form reservoirs of air that also permit the collection and dissipation of air through respiration. That's why you might see penguins with their bills wide open panting. This is partially conscious, but it is mostly autonomic as well.
Excellent Insulator: The thin fatty layer below the skin acts as an insulator, so when they do want to preserve heat, like when entering cooler waters, they can. This fatty layer is much thicker in the colder climate penguins.

12. 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
Body Size: Dependent on surface area to volume ratio.
Continuing on this 2nd question, there are a few other features to mention that aid the Spheniscus penguins in surviving in warmer habitats.
Penguins that have more surface area inhabit warmer climates and ones with less reside in cooler climates.
A larger object should lose heat more slowly as smaller objects release heat more quickly.
Larger penguins have a lower surface area to volume ratio. Heat has farther to travel.
Smithsonian 2010

13. Spheniscus Morphology
This last figure is just to reemphasize the evolutionary morphological changes the Spheniscus genus had to undergo in order to survive in warmer climates.
Integument (skin), Breeding, Osteology (bone formation), Myology (muscle formation)
Keeping these characters in mind, you can go back to the figure and note the high number of integument changes as well as the osteo & myo modifications that they endured. But most importantly noting, the skin changes.
Note that when Spheniscus branches off, the number of integuments (which are the changes in skin), osteology (evolution of bone formation), and myology (evolution of muscle formation) that they underwent in order to survive in the new, warmer, climates was the highest in the whole tree.

14. 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,  
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,
Olson, Storrs. "Fossil Counterparts of Giant Penguins from the North Pacific". Science November 1979: Vol 206,  
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:  
Bertelli, Sara, Noberto P. Giannini. "A phylogeny of extant penguins (Aves: Sphenisciformes) combining morphology and mitochondrial sequences". Cladistics 2005:

15. QUESTIONS?????