Geographic isolation

Содержание

Слайд 2

Geographical Isolation Geographic isolation is a term that refers to a

Geographical Isolation
Geographic isolation is a term that refers to a population

of animals, plants, or other organisms that are separated from exchanging genetic material with other organisms of the same species. Typically geographic isolation is the result of an accident or coincidence
Слайд 3

Since the two groups are in their own unique ecosystems and

Since the two groups are in their own unique ecosystems and each experience

unique pressures, they will adapt to their environment over time and can eventually become very different from each other. This has the end result of speciation.
For example, if snails slowly travel beyond a big canyon, the snails on one side will adapt to that environment and the snails on the other side will do the same with their environment. On one side, dark shells might hide them from predators. On the other side, bright coloring might let them stay cool in strong sunlight.
Over time, the two populations become more genetically differentiated and might become two distinct species with independent geographic ranges.
Слайд 4

Geographic isolation can be caused by many factors such as: Isolation

Geographic isolation can be caused by many factors such as:

Isolation by

Barriers
Isolation by Distance
Isolation after an Event
Isolation by Separation
Слайд 5

Isolation by Barriers The people of Finland, who are secluded to

Isolation by Barriers

The people of Finland, who are secluded to some

degree from the rest of the world by water, develop certain diseases due to the lack of genetic material from other ethnicities and races.
Physical barriers prevent fish from one stream from mating with fish from another stream, leading to a less varied gene pool among those fish. As time passes, the fish become unable to successfully mate with other groups.
A mountain range prevents two types of goat from mating, causing the gene pool to become less varied.
Слайд 6

Слайд 7

Isolation by Distance Cheetahs separated from a larger group mate with

Isolation by Distance

Cheetahs separated from a larger group mate with each

other, resulting in a less varied gene pool.
Genetic interchange between finches is prevented when a flock becomes isolated from the rest on an island. Eventually, the isolated group emerges as a completely separate species.
A group of genetically differentiated chimpanzees is unable to mate with any other chimpanzees outside of their group due to physical isolation, leading to the development of certain diseases that genetic material from the other chimpanzees would have prevented.
A group of genetically differentiated bottlenose dolphins is separated from other members of its species and eventually goes extinct.
Слайд 8

Слайд 9

Isolation after an Event An earthquake causes two populations to become

Isolation after an Event

An earthquake causes two populations to become separate

from each other. Over time, each species experiences genetic makeup specific only to their own smaller, less diverse populations.
When a piece of land breaks off from a continent, the animals on the piece of land are only able to reproduce with their own populations. This results in the animals becoming entirely separate species over time.
Temporary isolation from a larger population of flies results in species behavior that causes a subgroup of flies not to mate with one another. When the subgroup joins the larger group, the two are now unable to produce fertile offspring.
A forest fire causes the permanent separation of a group of deer from their native population, causing the small group to interbreed only with one another. Over time, the group becomes an entirely different species.
Слайд 10

Слайд 11

Isolation by Separation An isolated group of beetles on a hill

Isolation by Separation

An isolated group of beetles on a hill only

work, eat and mate with one another. As a result, only genetic material within that small group is exchanged, leading to a less varied beetle population than others that mate with different subgroups.
A population of brown-haired people is separated from those with other hair colors and, as such, does not mix genetically with populations of any other hair color, leading to a population that is of homogenous brown hair color.
A small and isolated town contains individuals who do not marry anyone who was not raised in the town, resulting in a less diverse gene pool than a less homogenous population.
Слайд 12

Examples Geographic isolation occurs when two populations of the same species

Examples

Geographic isolation occurs when two populations of the same species are divided by some type

of geographic event or object. This event or object physically prevents two populations from being in the same area, preventing them from mating.
As an example, let's look at a species of fish. These fish are all members of the same species, though some fish happen to have green scales and others happen to have pink scales. All the fish live in the east of the river.
One day, strong rain caused the river to flood, and the currents in the river became overpowering, sweeping some fish to the west of the river. Once in the west, the fish were unable to get back to the east.
Слайд 13

Population A happens to have more green fish than Population B.

Population A happens to have more green fish than Population B.

However, both groups are still members of the same species. Since the two populations will never be reunited, eventually the ratio of green fish will increase in Population A, and the ratio of pink fish will increase in Population B. Over time, each population will only have one color.
Слайд 14

THANK YOU


THANK YOU

Слайд 15

How nervous system can be damaged ? The nervous system is

How nervous system can be damaged ?

The nervous system is vulnerable

to various disorders. It can be damaged by the following:
Trauma
Infections
Degeneration
Structural defects
Tumors
Blood flow disruption
Autoimmune disorders
Disorders of
Слайд 16

Signs and symptoms of nervous system disorders Persistent or sudden onset

Signs and symptoms of nervous system disorders

Persistent or sudden onset of

a headache
A headache that changes or is different
Loss of feeling or tingling
Weakness or loss of muscle strength
Loss of sight or double vision
Memory loss
Impaired mental ability
Lack of coordination
Muscle rigidity
Tremors and seizures
Back pain which radiates to the feet, toes, or other parts of the body
Muscle wasting and slurred speech
New language impairment (expression or comprehension)
Слайд 17

These are some branch of medicine that deals with such disorders

These are some branch of medicine that deals with such disorders

Neurology
Neurological

surgery
Neuroradiologists and interventional radiologists
Rehabilitation for neurological disorders
Слайд 18

Neurology The branch of medicine that manages nervous system disorders is

Neurology

The branch of medicine that manages nervous system disorders is called neurology.

The medical healthcare providers who treat nervous system disorders are called neurologists. Some neurologists treat acute strokes and cerebral aneurysms using endovascular techniques.
Слайд 19

Rehabilitation for neurological disorders The branch of medicine that provides rehabilitative

Rehabilitation for neurological disorders

 The branch of medicine that provides rehabilitative care

for patients with nervous system disorders is called physical medicine and rehabilitation. Healthcare providers who work with patients in the rehabilitation process are called physiatrists.