Lab Class Mammalia

Similarities between pigs and humans

Pigs and humans are similar in the context that they both belong to the kingdom Animalia, which includes multicellular organisms that have specialized tissues and organs. Similarities also occur in their anatomy including similar dentition and use of heterotrophy in their feeding (MacKenzie, et al, 2004). They are omnivorous animals, that is, have the ability to consume plant and animal diets. Further, they both reproduce sexually and are placental mammals, meaning that their fetus receive nourishment from the mother through the umbilical cords during the gestation period (MacKenzie, et al, 2004).

Anatomical differences between pigs and humans

On the other hand, various differences separate pigs from humans. For example, at the fetal stage, the pig has a diffuse, epitheliochorial type of placenta, while humans have discoid, hemochorial type of placenta (MacKenzie, et al, 2004). Concerning mammary glands, pigs also have more pairs of nipples than humans (MacKenzie, et al, 2004). Pigs are ungulate animals with hooves that appear anatomically different from the feet and fingers of humans. Pigs walk on all their four limbs, while humans are bipedal. Compared to humans, pigs have bigger ears, and a pronounced tail, a feature that is vestigial in humans (MacKenzie, et al, 2004).

Classification of pigs and humans as mammals

Both pigs and humans are classified as mammals in the sense that they share distinctive mammalian features including having a vertebral column. They also have sebaceous glands, body hair, and are able to regulate their body temperature to warm levels (MacKenzie, et al, 2004). They have mammary glands that produce milk from which they feed their young ones. Other features unique to humans and pigs as mammals include, a four-chambered heart, a diaphragm, a single jawbone articulation, heterodont dentition, and use of lungs in respiration (MacKenzie, et al, 2004).

Why don’t pigs and humans share the same order?

Pigs belong to the Order Artiodactyla while humans belong to the Order Primates (Linzey, 2012). Pigs and humans do not share the same Order because they do not share characteristics that are specific to a single order. Animals classified under an order are closely related members in comparison to animals classified in a different order. For example, Artiodactyles differ from Primates by having even-toed limbs while Primates have a pentadactyl system (Linzey, 2012).

Order of the following animals/organisms:

Cats – Order Carnivora
Bears – Order Carnivora
Rhinoceros – Order Perissodactyla
Moles – Order Insectivora
Voles – Order Rodentia
Manatee – Order Sirenia
Guinea Pig – Order Rodentia
Hedgehog – Order Insectivora
Pikas – Order Lagomorpha
Baboons – Order Primates
Cows – Order Artiodactyla
Deer – Order Artiodactyla
Goats – Order Artiodactyla
Whales – Order Cetacea
Sloths – Order Edentata
Capybara – Order Rodentia
Pigs – Order Artiodactyla
Fruit Bats – Order Chiroptera

(Linzey, 2012).
What have you learned from doing this laboratory that you did not know before you began it?

I have learned that regardless of anatomical differences, various features that organisms help to classify related organisms in the same group in taxonomy.

References

MacKenzie, L., Arwine, D., Shewan, E., McHugh, M. (2004). Biology: A search for order in complexity. NY: Christian Liberty Press.

Linzey, D. (2012). Vertebrate biology. NY: JHU Press