Showing posts with label extinct. Show all posts
Showing posts with label extinct. Show all posts

August 12 - Quagga - gone!

 Posted on August 2, 2022     


This is an update of my post published on August 2, 2011: 


   



Have you ever heard of quagga? This kind of zebra looked as if whoever was in charge of painting stripes ran out of paint. The horselike animal, native to South Africa, had vivid stripes on the head and neck. In the mid-section of the animal the white stripes faded and dark in-between stripes became wider. The rear section was solid brown.

The quagga used to be be classified as an individual species, but now it is considered a sub-species of the plains zebra.



Unfortunately, the quagga was hunted to extinction for meat, hides, and to prevent it from competing with farm animals. The last of the wild quagga was probably killed in the late 1870s. There were still some quagga in zoos, but on this day in 1883, the last one died in a zoo in Amsterdam.

One of the foals of the Quagga Project

The quagga is the first extinct animal to have its DNA studied. Recently a natural historian began a project to recreate the quagga by selective breeding from plains zebra stock. In 2005 the first foal of the Quagga Project was born, and by 2006 creatures that look very much like the quagga-of-old had appeared. 

This sort of “breeding back” project is controversial. Apparently the project's goal is to reintroduce the quagga back into the wild, but some scientists say that even creatures that look like the quagga will not be true quagga. There is no technology, so far, to use DNA recovered from quagga specimens in breeding—and that, some say, would be what was necessary to truly bring back an extinct species.






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June 29 - Discovery of an Island Oxymoron

  Posted on June 29, 2022     


This is an update of my post published on June 29, 2011:



On this day in 1994, Dr. Tom Rockwell and his student Kevin Colson found the fossilized skull and shoulder blades of a pygmy mammoth sticking out the sand and rock on Santa Rosa Island, in California.

(The word pygmy means “small,” and of course mammoth means “large,” so the pygmy mammoth's name is an oxymoron—that is, a phrase that seems to contradict itself. Of course, mammoths were creatures in the elephant family; the various now-extinct mammoth species were quite hairy compared to modern elephants because they lived during the Ice Age and at higher latitudes than the equator-hugging lands where modern elephants live. The pygmy mammoth fossils discovered on a California island represents a kind of mammoth that is smaller than other mammoths.)


Pygmy mammoths compared in size to "regular
mammoths," above, and to a full grown human, below.




It turned out that the fossilized skeleton that Rockwell and Colson found was nearly complete. This is the only full-sized skeleton of this particular species found anywhere, and it is also the first to be dated—it's about 12,840 years old.

How do skeletons become fossils?

Most organisms rot away to nothing when they die. Very few become fossils—but so many creatures have lived in earth's loooong history, scientists have still managed to find billions of fossils, representing hundreds of thousands of different species.



Here's one way in which an organism can become fossilized:

  • An animal dies and falls to the bottom of a sea or lake.

  • Soft parts rot away, leaving the skeleton.

  • Dirt, sand, bits of rock and shell, and other sediment falls onto the skeleton and buries it.

  • As more sediment piles on, pressure increases on the lower layers, and they turn to hard rock.

  • The bones dissolve by ground water, leaving holes of the same shape, which act as molds.

  • Minerals crystallize inside the molds, creating fossils that are made of minerals but that have the same shape as the original bones.

  • Later (as in millions of years later), the rock is uplifted and exposed by erosion. The fossils are now exposed, waiting to be discovered.


Of course, some fossils are not mineralized bones (above)...
but rather impressions of shells or bones or even leaves or footprints (below)...




For a longer description of the process of fossilization, go here.




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June 4 - The Great Auk Goes Extinct!

   Posted on June 4, 2022     


This is an update of my post published on June 4, 2011:




Called “the penguin of the north,” although not closely related to penguins, the great auk was, in the 1800s, very much endangered by human hunting. People hunted this bird for its meat, feathers, and oil. It had disappeared from Norway by the 1300s, and its population had dramatically dipped elsewhere by the end of the 1600s. By the 1800s, one of the bird's last breeding spots was a small volcanic island off the coast of Iceland.

In 1830, an underwater volcanic eruption and earthquake destroyed that island.


With only a few survivors left in the entire world, the great auk settled on a few nearby islands. Someone beat the last bird on St. Kilda to death because he thought it might be a witch. The last pair, who lived on Eldey Island, were beaten to death by collectors—and their egg was broken, as well—on this date in 1844.

Was everyone blind to the problem that extinction is forever? Did nobody think ahead and realize that, if ALL the birds were killed for meat, oil, feathers, and trophies, then our supply of those things would be gone forever?

Actually, some people did realize that human exploitation was driving the bird to extinction, and they did plead with governments to protect the birds—to “stop the massacre.”  And some laws were passed and even enforced. But not enough.

Not enough laws and not enough enforcement, not soon enough, and not widespread enough, to save the great auk.


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