Why do Creatures go Extinct?

[melanie]

Unfortunately not ...... at least not in the life of a Universe.

The genetic code is over 3 billion characters long .... in order for an extinct species to appear again ... that particular code would have to randomly appear again in that exact same order. The chances of this happening are almost negligible, we execute murderers if their DNA is found at the crime scene .... this is how unlikely it is to occur twice.

I agree Greg.
And because there are millions of creature that inhabit earth - including millions of other species of creature that are yet to be discovered.
It makes sense that each creature would probably be a once in a life time unique event never to be repeated once gone. That's logical.
The chances of the exact same creature appearing again once extinct is remote.
They can no more come back, than......

It would be like....Painting the same picture a million times, lets say of a cat playing with a ball of string - and expecting those pictures to manifest exactly identical to one another it would be virtually impossible.

That makes everything totally special and unique never to be repeated, that's something to feel good about imo.
We have no right to judge some one because of their appearance, because every one is a one off.
We should appreciate ''one off's'' for what they are - the universe made them that way, so they were meant to be.

'Species' is just a delineation that we place on life when we see it behaving in distinct 'groups'. The reason a particular DNA code rises up as a species is it is 'fit' for the environment at that particular point in time. many fortuitous things come together .... when the majority of these things change, species go extinct. But extinction is not always death ... it can be change.

Homo Heidelbergensis was a species that seperated .... one group going north and the other remaining in Africa. The Northern group 'morphed' into Neanderthal, due to the cold conditions, the extreme difficulty of surviving ....etc ... they developed short barrell like bodies to retain heat, large noses to prevent over heating under extreme physical exertion and lost most of their ability to feel pain ...... this made them extremely tough creatures ....

The species that remained in Africa, Homo Sapiens, were placed under conditions of extreme drought ... most of them died ... at last, when there was only approx 300 left, they too, pushed north ........ They had different physical characteristics that allowed them to out-compete Neanderthal ... in the same environment

Heidelbergensis had all the traits of Neanderthal and Sapiens inside his DNA .... different conditions caused different traits to come to the fore. Heidelbergensis went extinct (he morphed into us and Neanderthal, our brother) he became Homo Sapiens (us) and Neanderthal.

So as you can see this is one form of extinction ... another form would be Paranthropus Boisei ... when environmental conditions changed he could not adapt (morph) fast enough ... and so a day came when the last of his line laid down and died leaving no further descendents .... he was, if you like, our Uncle, if a species can have an Uncle.

CLICK

Thanks Greg for this well explained info - it makes perfect sense to me. It's all coming back to me now

[melanie]

Mel .... If you get a chance go to your local DVD rental shop and take out 'Walking with Caveman' ..... It tells the whole story ... another great two DVDs are 'Walking with Dinousaurs' and 'Walking with Beasts' ... these tell the story of species going extinct and new ones appearing ... and also they are great viewing


cool bananas ... greg (there is a lot more that i have not posted on this)

Thanks Greg. These ''Walking with...'' stories are shown periodically on the BBC TV channels here in Britain.
I have seen them before .... You can see them on youtube as well.......http://www.youtube.com/watch?v=V8KLm0Uc0eI

[melanie]

cool bananas ... greg (there is a lot more that i have not posted on this)

Good - please keep posting what you've got.

I'm all ears


Thanks.

[melanie]

Celebrate; live; be,
For everyone dies,
But not everyone lives.

Very wise words Austin.

Excellent posts from you too.

Keep them coming.

[Graybeard]

Sometimes Pliers go extinct too ! ...... Or evolve into more 'fit' forms to suit their environment.

When an Electrician needs to grip a contact tighter and tighter ... he needs to use stronger and stronger pliers.

Trees grow nuts containing seeds that are plundered by birds .... The tree's tougher nuts survive because the birds can't crack them ... the seeds from these nuts grow tougher nuts as well ..

Some birds have (accidently) stronger beaks and can just manage to crack the tougher nuts ... and so survive longer to breed ... baby birds with stronger beaks who can crack tougher nuts ... etc, etc, etc. ... and the Arms Race is on !!

And then, one day you revisit ... and you find the nuts and the birds no longer look anything like they used to..

Overview

Life forms reproduce to make offspring.
The offspring differs from the parent in minor random ways.
If the differences are helpful, the offspring is more likely to survive and reproduce.
This means that more offspring in the next generation will have the helpful difference.
These differences accumulate resulting in changes within the population.
Over time, this process gradually leads to entirely new types of life.
This process is responsible for the many diverse life forms in the world today.

cool bananas ... greggy .... lolol

[melanie]

Greg,great post above thanks.

Now talking about the uniqueness of things ... take a look at these grains of sand.

Sand grains magnified 110-250 times reveal each grain is unique.





Magnified 250 times. Every grain of sand in the world is unique when viewed through a microscope.

[Graybeard]

And each one pretty enough to be set into a gold ring. Natures hidden jewels.

Picking up Pebbles and throwing them into the Sea

cool bananas ... greg

[Graybeard]

ALL GONE FOREVER




Tetrabelodon lived in North Africa, Europe and Asia during the Miocene (24 million to 5 million years ago) and the early Pliocene (5 million to 1.8 million years ago). Tetrabelodons had four tusks and one species stood more than 15 feet tall.



The Giant Ground Sloth, Megatherium americanum, was 18 feet long, as big as an elephant, and lived in South America during the Pleistocene until just a few thousand years ago. Other species from the size of a cat to that of the the giant ground sloth lived from the Arctic to Antarctica. They were hunted by humans and some believe humans may even have farmed them.



Pteranodon

There were 29 pterodactyl species ranging from the size of a small bird up to the size of a Quetzalcoatlus which was 20 feet long and weighed 500 lbs. The largest Quetzalcoatlus wingspan measured over 36 feet. They probably soared over long distances. Another Pterodactyl species, the Pterodaustros, had one thousand teeth.



Hypohippos a Miocene Horse inhabitated heavy undergrowth in North America. Early North American Horses were not the ancestors of present day horses.

[Graybeard]

GONE FOREVER



Passenger Pigeon

"The passenger pigeon needs no protection. Wonderfully prolific, having the vast forests of the North as its breeding grounds, traveling hundreds of miles in search of food, it is here today and elsewhere tomorrow, and no ordinary destruction can lessen them, or be missed from the myriads that are yearly produced."

Report of a select committee of the Ohio Senate in 1857 on a bill proposed to protect Passenger Pigeons.

One of the most noted of extinct animals, passenger pigeons were reduced from numbers in the hundreds of millions for food.



At one time the Passenger Pigeon was the most populous North American species estimated to number more than three billion.



Huge flocks blackened the skies for days along migration routes and nested in colonies covering dozens of square miles.

Tens of thousands of birds were commercially hunted each day and shipped in barrels east to restaurants. While thousands of Passenger Pigeons survived the great hunts, a combination of conditions contributed to the species’ inability to recover. Their birth rate was always low as they usually laid just one egg. Deforestation and agriculture changed their habitat. They were conditioned to huge nesting areas containing hundreds of thousands of nests. Their must have been incredible trauma when they were blasted from their breeding grounds and sought new areas. Some flocks, already grossly reduced bred further north where extreme weather may have affected mortality.



GONE FOREVER

The Passenger Pigeon

We were counted not in thousands, nor millions, but in billions.
Billions we were, numerous as the stars in the heavens
As grains of sand at the sea, as the buffalo on the plains.
When we burst into flight we so filled the sky
That the sun was darkened and day became dusk
Humblers of the sun we were!
The world inconceivable without us.
Yet it’s 1914, and here I am
Alone caged in the Cincinnati Zoo.
The last of the passenger pigeons.

by Paul Fleischman


Passenger Pigeon

"The migratory or wild pigeon of North America was known by our race as O-me-me-wog."

By Chief Pokagon - Simon Pokagon - of Michigan, a full-blooded Indian, the last Pottawattomie chief of the Pokagon band. From The Chautauquan," November, 1895. Vol. 22. No. 20. Reprinted in The Passenger Pigeon, by W.B. Mershon.

Me-me-og, The Wild Pigeon

In springtime when the rosy hand of morning light
Unfolds the curtain of an April night.
And golden clouds float in the liquid blue.
As guardian spirits, weeping crystal dew,

The frightened woodsman, in wonder list'ning stands!
Thinks a whirlwind is abroad in the land!
Darkness increases, his eyes grow dim.
And as he seeks shelter from the impending wind,

Suddenly his fears are turned to joy, for he sees Sweeping through
and high above the forest trees Millions of pigeons, on their north-bound way,
Almost shutting out the morning light of day!

Captain O.W. Rowland. History of Van Buren County, Michigan. Volume 1.

GONE FOREVER

[austintorn@aol.com]

Squall Line

The country people began to reappear in the early spring: the maple sappers, the menders of the stone fences, the pigeon hunters, the harbingers, and the new King, Percevale.

“Guinevere,” the King said, “it is time that we went out amongst the people of our country. There they are out in the countryside shaking off their winter fever.”

And so they went, greeting their subjects at every turn. It was a good time for a new King to appear. All was peace and was almost prosperity in the Land. The quiet of this rare calm March day was soon shattered, however, when it was broken by the sounds of a distant movement of air coming from the southeast. About three miles away dark clouds could be seen moving northwest at a rather startling rate. They appeared to be the rolling, boiling, black fog of a squall.

“This is odd,” said Percevale. “I feel no mass of charged air surrounding us. Then, too, a squall is rare for this season.” However, the faint but almost constant rumblings of thunder announced the threat of an upcoming storm, for as far as the eye could see, darkness filled the sky. The clouds wavered and fluctuated, and before long the sun was almost totally eclipsed. These clouds were of abnormal length and breadth, rolling furiously forward as they neared the great Oaken Forest. The faint thunder became an uproar, the winds changed to a great vibration of air that caused the ground beneath to tremble. The clouds were alive!—alive and propelled by a billion wings flapping in unison. Bluish-white excreta from the flying cloud gave the illusion of a disintegrating sky or of a late winter snowfall. The air became heavy with the odor of birds, millions of birds. The passenger pigeons were here. They were coming back from their migratory flight to the south.


(Those pigeons carried a lot of passengers in their days before the railroads came along.)