PSL280H1 Study Guide - Fall 2018, Comprehensive Midterm Notes - Pinniped, Marine Mammal, Mammal
12 Oct 2018
School
Department
Course
Professor
PSL280H1
MIDTERM EXAM
STUDY GUIDE
Fall 2018
PSL280H1(F) – Lecture 1
• Marine mammal: any aquatic mammal that spends part or all of its life in water (fresh & marine)
o Currently ~126 living species
• Number of species/distribution:
o 36 pinnipeds (seals, lions, walruses)
o 84 cetaceans (whales, dolphins, porpoise)
o 4 sirenians (manatee, dugong)
o 1 sea/marine otter
o 1 polar bear
• Japan’s river otter (a sub-species) has been declared to be extinct
• The vaquita is the world’s most endangered marine mammal à only ~12 left at last count
• New species are found à tiny new frog species found in India
• Definition of a species could be based on several factors, including morphology or DNA
o Morphology: study of form and structure of an organism without consideration of function
o DNA: nucleic acid that carries fundamental and distinctive characteristics of an organism
(oftentimes regarded as unchangeable)
find more resources at oneclass.com
find more resources at oneclass.com
2
o
Molecular genetics and evolution example:
• Comparing mitochondrial DNA of polar bears, brown bears, and black bears reveals that:
o polar bears are an older, distinct species than previously thought by as much as several
hundred thousand years
o this extra evolutionary time has given polar bears more time to adapt to the Arctic
environment
§ however, climate change has been and is rapidly occurring over the past 100 –
200 years… L
• The marine mammal species we’ll be studying in this course:
o Harbor seals
§ Sub-order: Pinnipedia
§ Family #1 of 3 families in total: Phocidae (true or ‘earless’
seals)
o Sea lions
§ Sub-order: Pinnipedia
§ Family #2 of 3 families in total: Otariidae (eared seals)
o Walruses
§ Sub-order: Pinnipedia
§ Family #3 of 3 families in total: Odobenidae
Based on morphology, there
should be 10 dolphin species….
… but based on DNA, there
should be 12 dolphin species….
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Based on morphology, there should be 10 dolphin species . However, climate change has been and is rapidly occurring over the past 100 . 200 years l: the marine mammal species we"ll be studying in this course, harbor seals. Family #1 of 3 families in total: phocidae (true or earless" seals: sea lions. Family #2 of 3 families in total: otariidae (eared seals: walruses. Family #3 of 3 families in total: odobenidae. Sub-order #1 of 2 sub-orders in total: odontoceti toothed whales (teeth + 1 blowhole: humpback whales. Sub-order #2 of 2 sub-orders in total: mysticeti baleen whales (no teeth + 2 blowholes: manatees (3 species) Family #1 of 2 families in total: trichechidae: dugong (1 species) Family #2 of 2 families in total: dugongidae: sea/marine otter. 3: class mammalia = all species classified as mammals, have the following similar characteristics: Body covered with hair which molts (sheds hair) 4 limbs (may be visually absent in some!)
