Lab 8 Animal Adaptations Flashcards Preview

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Flashcards in Lab 8 Animal Adaptations Deck (22):
0

Variation that we see among species in coloration, morphology and behavior reflects

Adaptations to specific environments or to particular ecological lifestyles

1

What does fossil records indicate about earliest mammals

1. Small
2. Shrew- like
3. Fed on small prey and insects
4. Evolutionarily conservative for 10s of millions of years

2

Evolution of early mammals after extinction of dinosaurs ( 65 million years ago)

Mammals underwent adaptive radiation and evolved into a wide variety of life forms

Secondary bouts of adaptive radiation later gave rise to most of our modern groups such as primates, rodents and ungulates

3

Mammals evolved from

Reptiles

4

How are mammals distinguished from reptiles

A variety of derived traits
Presence of hair
Mammary glands which produce milk
Internal development of embryos
Tooth morphology ( reptiles.... Homondont/ mammals heterodont)

5

Homodont

. Found in reptiles
. Condition where all teeth are roughly similar in size and shape

6

Heterodont

. Found in mammals
. Teeth differ in size and shape

7

What does tooth shape and number correlate with

. Feeding biology of mammals

8

What caused a dramatic increase in the diversity of tooth shapes and sizes

Adaptive radiation

9

What are the 4 major types of teeth found in mammals

Incisors
Canines
Premolars
Molars

10

Why do reticle have homodont teeth

?

11

Incisors

Incisors.... Tearing
Canines.... Piercing
Premolars and molars ..... Crushing and grinding

12

DENTAL FORMULA

. Used to describe the number and kinds of teeth found in mammals
. Consist of the number and type found on the upper and lower portions of one side of the mouth. Then multiplied by 2 gives the total number of teeth in the mouth

13

Carnivores

CARNIVORES : such as dogs and cats, generally have large pointed incisors and canine that can be used to kill prey, or rip or cut away pieces of flesh. Jagged premolars and molars crush and shred food.

14

Herbivore

Such as horses and deer, usually have molars and premolars with broad ridged surfaces that grind tough plant material. Incisors and canines are modified to bite off pieces of vegetation. In some herbivores canines are absent

15

Omnivores

As in humans are adopted to eating both plants and meat.
Incisors for biting
Canines for tearing
Premolars for grinding
Molars for crushing

16

Purpose of hair

To provide heat

17

2 classifications of hair

Guard hair
Under fur

18

Guard hairs

Larger, coarser hairs that are more apparent on the outer surface of the body

19

Underfur

Is composed of finer, shorter hairs that are not apparent until the fur is parted

20

Why is hair shed

Because they are dead at maturity

21

Function of hair

Heat conservation
Special air filled for buoyancy caribou
Camouflage
Water repellent
Protection from predators