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As species are split up along the planet, they endure changes which better help they adapt to their surroundings. This is shown on a much smaller scale in the Galapagos islands as the Finches on different islands differ in beak size which is directly related to their food source.

Totaled 3/20/10 Mr F

Totaled 3/29 Mr F

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Closed 3/29/10 Mr F 

  Another area of evidence found and proven the theory of evolution is GEOGRAPHICAL DISTRIBUTION of species! It seems as though major isolated land areas and island groups often evolved their own distinct plant and animal communities.  For example, before humans evolved, Australia contained more than 100 species of kangaroos, koalas, and other marsupials but none of the more advanced terrestrial  placental mammals  such as dogs, bears and horses. 

     Land mammals were  absent from the more isolated islands.  Each of these isolated land areas and islands had a great # of plant, insect, and bird species that lived only in that region of land.  The  explanation for this existence of Australia's, Hawaii's and other islands and lands, mostly unique biotic environments is that the life forms in these areas had been evolving in isolation from the rest of the world for millions of years.  

Here is a video describing geographical distribution using an example of salamanders. It is really cool to figure out why there are so many variations of one species of salamander - just because they were separated through California. 

         Geographical distribution is the natural arrangement of animals and plants in particular regions.  For example. wild potatoes are found in significant numbers along the west coast of South America and Central America.  Along the borders of Mexico, Peru, Bolivia and Argentina.  They are found there because of the conditions that are present.  The conditions there are good for potatoes to grow, while other countries have conditions good for growing other plants.

          In other instances animals from the same species, get seperated, and therfore grow in different places.  This is where adaptation comes into place.  The better adapted animals will survive and reproduce, therefore making the next generation more adapted.  Such as birds that get seperated, some get longer beaks in order to eat insects out of small spaces, while some birds are scavengers and have bald heads in order to not attract harmfull bacteria.

     Animals who adapt the same tend to stay together. in the video above, the salamanders would join together if they had the same adaptation traits. 

     One of the earliest examples of geographical distribution would be pangea.  When all the earths land was together in one piece.  Once it started seperating into different continents the species were split.  This caused different species to adapt differently to the conditions on their continent, and forming different species.

Adaptation is the evolutionary process whereby a population becomes better suited to its habitat. This process takes place over many generations, and is one of the basic phenomena of biology.

Species adapt due to the location they are in. heres a fun video that talks about a camel. 

Speciation is the evolutionary process by which new biological species arise. The biologist Orator F. Cook seems to have been the first to coin the term 'speciation' for the splitting of lineages or 'cladogenesis,' as opposed to 'anagenesis' or 'phyletic evolution' occurring within lineages. Whether genetic drift is a minor or major contributor to speciation is the subject of much ongoing discussion. There are four geographic modes of speciation in nature, based on the extent to which speciating populations are geographically isolated from one another: allopatric, peripatric, parapatric, and sympatric. Speciation may also be induced artificially, through animal husbandry or laboratory experiments. Observed examples of each kind of speciation are provided throughout

Geographical Distribution can also lead to speciation- A process whereby over time one species evolves into a different species (anagenesis) or whereby one species diverges to become two or more species (cladogenesis).

It can lead to this because it can physically seperate a species with land barriers such as rivers, canyons, and mountains. An example of this is down below: 

This picture represents the geographical distribution of rusty crayfish, which have spread into rivers and streams in the Midwest.  This shows how a species can migrate to other locations (and possibly adapt.)  It shows where the species originally lives, and where else it is distributed.  It mostly migrated to areas near large bodies of water.

 Extent of the Fossil Record:

Despite the relative rarity of suitable conditions for fossilization, approximately 250,000 fossil species are known.The number of individual fossils this represents varies greatly from species to species, but many millions of fossils have been recovered: for instance, more than three million fossils from the last Ice Age have been recovered from the La Brea Tar Pits in Los Angeles. Many more fossils are still in the ground, in various geological formations known to contain a high fossil density, allowing estimates of the total fossil content of the formation to be made. An example of this occurs in South Africa's Beaufort Formation (part of the Karoo Supergroup, which covers most of South Africa), which is rich in vertebrate fossils, including therapsids (reptile/mammal transitional forms) It has been estimated that this formation contains 800 billion vertebrate fossils.

This picture shows the specialized traits of species based on where they live.

A good example of geographical distribution is how there were Neanderthals living in regions from western Asia to the Middle East to Europe close to 40,000 years ago.  There is genetic evidence to show that the Neanderthals that lived in each area were genetically different, and the size of their populations changed, and some migrated to other locations, possibly to find a habitat better suited for their characteristics.  Scientists discovered this mainly through paleoanthropology.  

In this picture, you can see how the Neanderthals had a similar structure to humans, but you can also see how they can resemble primates.  This shows a modification of the skeleton.

This picture shows the speciation of mockingbirds in the Galapagos Islands. Different islands contain different species that are unique to the territory they inhabit, in most cases, due to the food source on that island

This is a perfect representation of geographical distribution- the distribution of butterflies throughout Central and South America.  These butterflies are the species Heliconius melpomene.  Although they are technically the same species, they have differently colored wings, which shows their adaptations to their environments.  They have about 30 sub-species.

This video shows the geographical distribution of finches in the Galapagos Islands, and how Darwin used this to formulate his theory of evolution.  This is the best example of geographical distribution because the finches on each island had adapted to their environments through their beak shape and size.