Mod 1 Flashcards
Darwin’s theory of evolution
- Variation
- Over reproduction
- Competition
- Natural selection
- Evolution
How many years ago did cetacians evolve?
53-54 mya
How many years ago did sirenians evolve
50 mya
How many years ago did baleen whales evolve?
35 mya
How many years ago did pinnipeds evolve?
25-27 mya
How many years ago did true seals evolve?
20 mya
How many years ago did the walrus evolve
15 mya
How many years ago did the fur seals evolve?
11 mya
How many years ago did sea otters evolve
1-3 mya
How many years ago did polar bears evolve?
0.5-1 mya
What is the first differentiator of a deuterostome?
The blastopore becomes the anus, and the gut does not travel through the brain
What structures do the pharyngeal slits form in chordates?
Jaw, hyoid, ears, larynx, and lungs
What does the dorsal hollow nervous system do?
Coordination of locomotion with sensory info from the environment
What does the notochord do?
stores energy for increased locomotion efficiency
Mammalian characteristics
Hair/fur, mammary glands, homeotherms/warm blooded
Names of the ear bones
Malleus, incus, stapes
deuterostome blastopore becomes the ___
anus end of the gut
t/f: early mammals gave live birth
false, they still laid eggs
material baleen is made of
keratin
specially adapted talus (ankle bone),smooth pulley on 2 sides, used by animals specialized in running, evidence that pakicetoid early whale ancestor
astralagus
The posterior gill slits become
The laryngeal skeletob
how many years ago did mammals first evolve?
125 mya
the first trait to evolve within the vertebrate lineage
bone protecting the brain and spinal cord
geological event that preceded the evolution of the major phyla of animal lineages
weathering of minerals from land into ocean
original function of hair in mammals
navigation in underground burrows
two structures that are analogous share
function
two structures that are homologous share
common ancestry
where pinnipeds, sea otters and polar bears first appeared in the marine environment
north pacific
manatees and dugongs are most closely related to this terrestrial animal
elephants
t/f: a pyruvate with less than 3 carbons in its chain can go through anaerobic respiration
false, only one with a chain of more than 3 carbons
why is o2 more concentrated in the blood in muscles than in the lungs in deep diving mammals?
the lungs deflate with more pressure from h2o at lower depths
how do marine mammals prevent the bends?
exhaling before diving, alveolar collapse
inadequate blood supply to an organ or part of body
selective ischemia
how do walruses eat?
via suction
how do toothed cetaceans eat?
suction through front gap in teeth
how do manatees eat?
grinding plant material with molar like teeth
marine mammals that hear with their jaws
cetaceans
how do manatees hear?
via the zygomatic arch
mustelidae
sea otters
