Evolution
This concept defines species based on reproductive isolation and is challenged by hybridization in wolves
the Biological Species Concept
What dental features are most characteristic of an insectivorous mammal?
Numerous small, sharp, similarly shaped (homodont) teeth
The formation of a new geographic barrier that splits an existing population into two new populations is known as what?
Vicariance
Name the Four chambers in a Ruminants Stomach?
Rumen, reticulum, omasum, abomasum
Torpor and hibernation are functionally identical forms of dormancy that differ only in the species that use them (T/F)
FALSE. Torpor is a short-term, sometimes daily or involuntary, state, while hibernation is a prolonged, deep, seasonal, and regulated state often lasting weeks or months.
This evolutionary process explains how traits such as dentition or claw morphology become more common in a population when they increase survival or reproductive success.
Natural selection
Claws, nails, and hooves are all composed of (what protein) and differ primarily in shape and function rather than material. Is this statement true or false?
TRUE. Keratin.
Name the 7 Biogeographic realms that we covered in class.
- Nearctic
- Palearctic
- Neotropical
- Afrotropical
- Indomalayan
- Australian
- Oceanic
Name an advantage that foregut fermenters have over hindgut fermenters?
Fermentation prior to small intestine to maximize nutrient absorption.
How do mammals increase their metabolic rate to balance heat loss in their environment?
Primarily through endothermy, using mechanisms such as shivering, non-shivering thermogenesis (burning brown fat), increasing physical activity, and elevating food consumption to digest more nutrients
In genetic drift, traits do not influence survival (True/false)
True. If traits influenced survival then it would be natural selection!
This carnivore tooth pair (upper P4 and lower M1) functions to shear meat.
Carnassial teeth
What land formation allowed the Great American Biotic Interchange to take place?
Isthmus of Panama
Based on :
Simple stomach, short intestine, short colon, short cecum (sometimes absent);
High protein diet - energy efficient
What class of diet classifies this animal?
This term: _______________ describes animals that maintain a relatively constant internal body temperature through metabolic heat production.
What is one advantage of this type of temperature regulation?
Endothermy.
Advantages: constant internal temps allow for greater degrees of complexity, they are able to remain active over a wider range of temps, can colonize many diverse environments -- all lead to greater diversity.
This stochastic (random) process has stronger effects in small populations and can lead to fixation or loss of alleles.
Genetic drift
This order of mammals has a dental formula of 1/1 incisors, no canines, and ever-growing front teeth. A large gap (called _________) exists between the incisors and the molars/premolars. Name the order and term.
Rodentia. Diastema
Name 3 patterns noted in mammalian island populations.
- dwarfism
- gigantism
- Vulnerability to extinction
- Rapid divergence
The Hindbrain
The thermal neutral zone of arctic species is typically larger than the thermal neutral zone of tropical species (true/false)
True. The the thermal neutral zone of tropical species is typically smaller and has less variation than the thermal neutral zone of arctic species.
The main mechanisms for evolution are:
natural selection and genetic drift
Unlike claws, this primate structure is flattened and improves fine motor control.
Define Bergmann's and Allen's rule.
Bergmann's - Larger animals in colder climates
Allen's- Shorter appendages/limbs in colder climates.
The cognitive limit to number of individuals you can maintain a stable social relationship is known as?
Dunbar's number
This physiological response reduces heat loss by decreasing blood flow to extremities in cold environments.
Vasoconstriction (the narrowing of blood vessels caused by smooth muscle contraction, reducing blood flow and increasing blood pressure)