Adaptation Natural and Artificial Selectionscientificrealms.weebly.com/uploads/3/7/4/0/37403077/7th_unit_11... · Adaptation Tuesday, March 25, 2014 Adaptation is the evolutionary

Adaptation

Tuesday, March 25, 2014

Natural and Artificial Selection

Adaptation


Adaptation is the evolutionary

process whereby a population

becomes better suited to its

environment (where it lives).

This process takes place over

many generations, and takes

time to happen.

Beaver

How is this animal adapted

to fit it’s environment?


Beaver

Due to a unique respiratory system, the beaver can remain

underwater for up to 20-minutes at a time.

The tail of the beaver is unusually broad and covered in scales.

Can use it like a rudder and as a communication tool.

Nostrils and ears that can close while under water.

Flaps of skin behind incisors to prevent drowning.

They have specialized teeth that are extra sharp. Beavers exist on

a diet of bark, twigs and buds of trees.


Woodpecker




Woodpecker

A strong, pointed beak acts as both a chisel and a crowbar to remove

bark and find hiding insects.

Barbed or brush-like tongue to extract insects or sap.

Zygodactyl feet, two toes forward and two toes backward.

Skull adapted to absorb shock of pecking on wood. Woodpeckers

tap an estimated 8,000 – 12,0000 times/day.

Nose/nostril feathers to prevent inhalation of wood particles.


Camel




Camel

The camel‘s mouth adapted to eat desert plants. It has no teeth

on its front upper jaw, which is a hard pad. It has teeth on its lower

jaw and teeth in the back of its upper and lower jaws.

A camel’s fat filled hump can store up to 20 L of water, and it

can go up to three days without water.

Eyelashes (2 rows)/slit-like nostrils to keep out sand.

Large, flat feet to spread their weight on the sand.

Thick fur on the top and thin fur everywhere else.


AdaptationsHaving certain colors can help a n o rganism

blend in with thei r s u r roundings .

Certain o rgans help o rganisms survive in

thei r environments (ex. bird’s hollow bones,

camel’s hum p) .

Mimicking other animals (like h aving yellow

and black str ipes) only works if the other

animals in the environment a re familiar

with th a t predator.


Natural Selection

Natural selection is the process in nature by which only the

organisms that are best adapted to their environment tend

to survive and reproduce. This passes on their inherited traits

to the next generation. Individuals that are not well adapted to

their environment tend to die before reproducing.

Therefore the traits that helped the organism survive get passed

on to their offspring.

Natural selection is the tool by which animals are able to

adapt.


Survival of the Fittest

Millions of years of natural selection have led to a range of

canines adapted for survival in many diverse habitats.

Today 35 species of wild canines can be found from the

tropics to the tundra.

Wild canines make their homes in a wide variety of habitats.

From the hottest deserts to the icy arctic, each wild canine has

been modified by natural selection so that it is well suited for

survival.


GrasslandsThe maned wolf is well

adapted for life in the tall

grass plains of South

America. Their stilt-like

legs aren't for r unning –

it is speedster. Instead,

long legs help maned

wolves peer over tall

grasses to spot each

other and their prey.


DesertThe fennec fox makes its

home in the desert. Pale fur

reflects the sun's rays, and

extends over the soles of its

paws to protect against hot

desert sands. When fennec

foxes overheat, its body sends

blood to their large ears to

rapidly dump the excess body

heat into the environment.


ArcticThe arctic fox is the only

year- round small canine

resident of the Arctic.

Its fur goes from white in

winter to brown-gray in

summer. For warmth,

thick fur covers the soles

of its feet and tiny ears to

reduce heat loss when

the temperature dips far

below zero.


Artificial Selection

Artificial selection or more commonly called

selective breeding is a resul t of humans,

r a t h e r th an na tu re selecting for a certain

trai t , causing changes in a population.

There a re m a ny exam ples of a r tificial

selection, including the food we eat,

domesticated animals, our pets and even the

meats we eat.





Man’s BestFriend

Selective breeding or artificial selection has created the many different dog breeds we are familiar with.

With artificial selection, humans decide which dogssurvive and breed.

With natural selection, onlythose that can meet nature's challenges are the ones that survive and breed.


Downsides to SelectiveBreeding

A rtificial selection essential ly removes variation in a

population, so selectively bred organisms can be

especially susceptible to diseases or changes in the

environment tha t would not be a problem for a

na tu ra l population.

Inbreeding – the mating of closely related

individuals – is also a problem. In dogs, this has

resul ted in breeds tha t h ave heal th issues ranging

from decreased life span to crippling lameness or

painful a r thrit is .


Downsides

Labrador - arthritis

Doberman – narcolepsy

Hairless Chinese Crested -

skin problems


Darwin’s Finches

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Adaptation Natural and Artificial Selectionscientificrealms.weebly.com/uploads/3/7/4/0/37403077/7th_unit_11... · Adaptation Tuesday, March 25, 2014 Adaptation is the evolutionary