0
   

Rain Forest #65 - Lions, and Tigers, and Bears, Oh My!

 
 
sumac
 
  1  
Reply Sat 7 Jan, 2006 09:02 am
http://www.nytimes.com/2006/01/06/science/06cats.html?ei=5070&en=996007c6e16b8f2f&ex=1137301200&pagewanted=print

January 6, 2006
DNA Offers New Insight Concerning Cat Evolution
By NICHOLAS WADE

Researchers have gained a major insight into the evolution of cats by showing how they migrated to new continents and developed new species as sea levels rose and fell.

About nine million years ago - two million years after the cat family first appeared in Asia - these successful predators invaded North America by crossing the Beringian land bridge connecting Siberia and Alaska, a team of geneticists writes in the journal Science today.

Later, several American cat lineages returned to Asia. With each migration, evolutionary forces morphed the pantherlike patriarch of all cats into a rainbow of species, from ocelots and lynxes to leopards, lions and the lineage that led to the most successful cat of all, even though it has mostly forsaken its predatory heritage: the cat that has induced people to pay for its board and lodging in return for frugal displays of affection.

This new history of the family, known as Felidae, is based on DNA analyses of the 37 living species performed by Warren E. Johnson and Stephen J. O'Brien of the National Cancer Institute and colleagues elsewhere.

Before DNA, taxonomists had considerable difficulty in classifying the cat family. The fossil record was sparse and many of the skulls lacked distinctiveness. One scheme divided the family into Big Cats and Little Cats. Then, in 1997, Dr. Johnson and Dr. O'Brien said they thought most living cats fell into one of eight lineages, based on the genetic element known as mitochondrial DNA.

Having made further DNA analyses, the researchers have drawn a full family tree that assigns every cat species to one of the lineages. They have also integrated their tree, which is based solely on changes in DNA, with the fossil record. The fossils, which are securely dated, allow dates to be assigned to each fork in the genetic family tree.

Knowing when each species came into existence, the Johnson-O'Brien team has been able to reconstruct a series of at least 10 intercontinental migrations by which cats colonized the world. The cheetah, for instance, now found in Africa, belongs to a lineage that originated in North America and some three million years ago migrated back across the Bering land bridge to Asia and then Africa.

Dr. O'Brien said the cats were very successful predators, second only to humans, and quickly explored new territories as opportunity arose. Sea levels were low from 11 million to 6 million years ago, enabling the first modern cats, in paleontologists' perspective (saber-tooth tigers are ancient cats), to spread from Asia west into Africa, creating the caracal lineage, and east into North America, generating the ocelot, lynx and puma lineages.

The leopard lineage appeared around 6.5 million years ago in Asia. The youngest of the eight lineages, which led eventually to the domestic cat, emerged some 6.2 million years ago in Asia and Africa, either from ancestors that had never left Asia or more probably from North American cats that had trekked back across the Bering land bridge.

Sea levels then rose, confining each cat species to its own continent, but sank again some three million years ago, allowing a second round of cat migrations. It was at this time that the ancestors of the cheetah and the Eurasian lynxes colonized the Old World from the New.

Chris Wozencraft, an authority on the classification of carnivorous mammals, said the new cat family tree generally agreed with one that he had just published in Mammal Species of the World, a standard reference. Dr. Wozencraft, a taxonomist at Bethel College in Indiana, based his classification on fossil and zoological information, as well as on DNA data already published by Dr. O'Brien's laboratory.

Cat fossils are very hard to tell apart, because they differ mostly just in size, and the DNA data emerging over the last decade has helped bring the field from confusion to consensus, Dr. Wozencraft said.

Despite their evolutionary success, most of the large cats are in peril because their broad hunting ranges have brought them into collision with people. "With the exception of the house cat and a few other small cat species, nearly every one of the 37 species is considered endangered or threatened," Dr. Johnson and Dr. O'Brien write in the current Annual Review of Genomics and Human Genetics.

Fewer than 15,000 tigers, cheetahs and snow leopards remain in the wild, they estimate, and pumas and jaguar populations have been reduced to about 50,000 each.
0 Replies
 
danon5
 
  1  
Reply Sat 7 Jan, 2006 09:17 am
sumac, very interesting. It appears there is a formula involved - "more humans, fewer cats"

---------

Here is a totally unrelated story I just read =

"DAYTON, Ohio The first black American to earn a pilot's license will be enshrined in the National Aviation Hall of Fame next year.

Atlanta, Texas native Bessie Coleman earned her pilot's license in France in 1921. She postponed her dream to start a flying school for blacks and earned a living performing aerobatic flying demonstrations at air shows.

Coleman died in an aviation accident in 1926 while flying with a mechanic in preparation for an air show in Florida. The mechanic was operating the plane when it malfunctioned. Coleman fell from the open cockpit to her death.

Other enshrinees announced today include pilot and actor Cliff Robertson, David Lee "Tex" Hill and Robert White.

They'll be inducted in July."

That's my home town............. While in France learning to fly - her instructor pilot was Anthony Fokker (the famous WWI aviator and founder of the Fokker Aircraft Company which still builds planes to this day.)
0 Replies
 
pwayfarer
 
  1  
Reply Sat 7 Jan, 2006 09:57 am
Here in Connecticut to celebrate the twin's fifth birthday. Leader board still reads
49.992 cres. I KNOW we must have gone over. What a wild clicking bunch - and ebeth, I remember when you put up the clothes line. So long ago!
0 Replies
 
ehBeth
 
  1  
Reply Sat 7 Jan, 2006 11:24 am
aktbird57 - You and your 285 friends have supported 2,178,218.9 square feet!

Marine Wetlands habitat supported: 92,169.1 square feet.
You have supported: (0.0)
Your 285 friends have supported: (92,169.1)

American Prairie habitat supported: 45,926.6 square feet.
You have supported: (11,307.0)
Your 285 friends have supported: (34,619.6)

Rainforest habitat supported: 2,040,123.1 square feet.
You have supported: (167,864.3)
Your 285 friends have supported: (1,872,258.8)

~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~

whooooooooooooooohoooooooooooooooooooooo

[/color][/size]

<drumroll please>
0 Replies
 
ehBeth
 
  1  
Reply Sat 7 Jan, 2006 11:28 am
http://www.prosperity.com/fun/nathan/graphics/drumroll.jpghttp://www.sitcomsonline.com/photopost/data/947/4485Scott_Baio_playing_drumroll.jpghttp://www.subdudes.com/images/shows/fitzgeralds2005-07cj/Drum%20roll,%20please.jpg



2178218.9 square feet is equal to 50.01 acres[/i][/color][/size]
0 Replies
 
Anon-Voter
 
  1  
Reply Sat 7 Jan, 2006 12:24 pm
Way to go you guys!!

Anon
0 Replies
 
ehBeth
 
  1  
Reply Sat 7 Jan, 2006 12:27 pm
Anon - you've been one of the team for a long time <discovered that when I sent the announcement email from inside the account - found a couple of your old accounts that you'd clicked from in the Abuzz day>

so - way to go - you guy! Very Happy
0 Replies
 
Stradee
 
  1  
Reply Sat 7 Jan, 2006 01:00 pm
WhuuuuuuuuuuuuuuuuuuuuuHuuuuuuuuuuuuuuuuuuuuu

Just too cool wildclickers!! Very Happy Very Happy Very Happy Very Happy

terrific articles sumac and Dan!!

alls well sumac, thanks! walls still holdin' - more rain today though after a reprieve from the weather - nature brought two beautiful sunny days for the Sierras illuminating snow covered mountains at higher elevations.
Tahoe breathakingly beautiful - the air crisp, clean, and well - just a picture post card that i have no words for describing.

Drum rolls reverberating, a2k rockin', and ehBeths clothline waves from Canada! Very Happy



Have a terrific day all ~
0 Replies
 
devriesj
 
  1  
Reply Sat 7 Jan, 2006 01:09 pm
Here's hoping you and yours continue to stay dry, Stradee!

I've only been part of it for the last few acres or so, but I'll be around for the next 50! Yeah, wildclickers!!
0 Replies
 
sumac
 
  1  
Reply Sat 7 Jan, 2006 01:59 pm
WHOOP!!!!!![/b]
0 Replies
 
sumac
 
  1  
Reply Sat 7 Jan, 2006 02:13 pm
Heads up, Stradee.

SEATTLE POST-INTELLIGENCER
http://seattlepi.nwsource.com/local/254746_stardust06.html

On the trail of cosmic mysteries, Stardust heading home
Craft carrying tiny particles with big secrets heads home

Friday, January 6, 2006

By TOM PAULSON
SEATTLE POST-INTELLIGENCER REPORTER

In about a week, a space capsule carrying the oldest material in the solar system will create a night fireball as bright as the moon, potentially visible from Washington to Utah, as it re-enters the atmosphere faster than any other man-made object has ever returned to Earth.


MULTIMEDIA
Please see NASA's site at stardust.jpl.nasa.gov/theater/index.html for animations and other information on the returning spacecraft.

Everyone is hopeful the parachutes will open this time.

"It's hard to convey to people how tense these situations can be," said University of Washington astronomer Don Brownlee, principal scientist for NASA's Stardust mission.


On Jan. 15, at 2:12 a.m. PST, Brownlee and his colleagues hope to celebrate the successful touchdown in the Utah desert of a 100-pound space capsule that will set all sorts of astronomical science and space exploration records -- the first deep space sample return, the farthest return trip of any spacecraft (nearly 3 billion miles) and the fastest re-entry speed (28,000 mph when it first hits the atmosphere).

And that doesn't even begin to describe the potential scientific breakthroughs to come from studying the collected dust of a pristine comet and other interstellar particles.

The tiny particles contain big secrets. They are thought to hold the original materials from which everything in our solar system, including life, was created.

But before the science begins, they have to get Stardust's precious cargo back on Earth safe and sound. The last NASA space capsule to "land" at the same place, the Air Force Utah Test and Training Range southwest of Salt Lake City, was the Genesis probe in September 2004. Genesis' parachutes failed to deploy, and it smashed into the desert floor, cracking open and contaminating some of its cargo of collected solar wind particles. NASA officials say they are confident that Stardust's parachutes will not fail, despite the fact that Lockheed Martin Space Systems built both spacecraft and their chute systems.

Brownlee shrugged off the concerns, noting Stardust's parachutes are different, simpler, so there's less to go wrong. Besides, he added, "We really have no control over it anyway once it starts coming back in."

Launching the $212 million Stardust spacecraft Feb. 7, 1999, was much more nerve-racking, Brownlee said. Launches have a 95 percent success rate, he noted, which from a grimmer perspective means they don't succeed one out of every 20 times.

When Stardust first went up, the radio signals from the craft began fading. Everyone went silent, Brownlee said, until the signals returned. Then, he said, there were indications the spacecraft was starting to fire some of its thrusters (made in Redmond by what was then Primex, now Aerojet) willy-nilly -- technically, "uncommanded thrusting."


"It felt like the whole thing was on the verge of disaster," Brownlee said. "There was this guy with his finger on a button to blow the vehicle up if it went off range. ... No one said anything for minutes."

Then, somehow, Stardust pulled itself together, began operating as expected and headed off on its interplanetary journey to rendezvous with a comet named Wild 2 (pronounced "vilt") that recently had come in from the edge of our solar system.

The mission since then, Brownlee said, has been amazingly glitch-free and has already produced new insights into comets. When Stardust finally encountered Wild 2, on Jan. 2, 2004, the spacecraft was able to shoot some close photos of the comet.

"They were spectacular and surprising," Brownlee said.

Wild 2 didn't look like it was supposed to, according to standard theory. Distant analyses of other comets such as Halley's had led scientists to think of comets as loose, unstructured piles of ice, dust and rocks. Wild 2 had craters and spires hundreds of feet tall -- indicating a firm structure. Numerous gas jets were shooting out of it.

"It was really weird-looking," Brownlee said.

But the real scientific prize was obtained not by looking, but by snatching.

"The primary purpose of the Stardust mission was to collect comet dust, the most basic material of the solar system, and bring it back to Earth for study," said Brownlee, as if repeating the proposal he made to NASA more than a decade ago.


Paul Joseph Brown / P-I
UW astronomer and Stardust lead scientist Don Brownlee illuminates, with a laser pen, a material called aerogel, a superlight glass foam used on Stardust to collect cosmic dust.
The UW astronomer, a member of the National Academy of Sciences, is world-renowned for his work studying cosmic dust, interstellar particles -- stardust. But all of the particles studied so far have been collected relatively close to home.

Earth's proximity to the sun alters these particles, chemically and physically.

Brownlee wanted to get his hands on some pure stardust, the unadulterated material from which everything -- including life itself -- was created.

"Virtually all of the atoms in our bodies came from the kind of grains we collected from the comet," he said. Billions of years ago, he said, our solar system was mostly a swirl of comets and cosmic dust that eventually aggregated into stars and planets.

But exactly how this happened, how the solar system came to be, how the Earth formed to retain a little water (and, relative to the size of our planet, the water is just a thin film), how biological life first came about and all the rest, Brownlee said, is still not fully understood. The public paid little attention to Stardust when it encountered the 3-mile-wide Comet Wild 2 in 2004, likely because of competing space news that NASA's Mars rover Spirit was about to land for an extended hike about the red planet. But many in the scientific community were more focused on Brownlee's spacecraft, anxiously waiting to hear if it succeeded.

The best way to imagine what it took for Stardust to capture and preserve the comet dust is to think of a ballet dancer being shot from a cannon into an active combat zone and told to execute a perfect "tours en l'air" while getting sandblasted.

The spacecraft approached to within 150 miles of Wild 2, flying through the coma -- the cloud of dust, gas and water vapor at the front of the comet. Most of the spacecraft was shielded from the particles striking it at high speeds. But one instrument, a tennis-racket shaped collector, was exposed to meet the particle storm head on.

In this instrument were trays of aerogel, an aerosolized glass-like substance that is the lightest solid material on Earth (99.8 percent air trapped in a silicon framework). Based on flyby measurements taken at the time of the space rendezvous, Brownlee and his colleagues believe the aerogel captured thousands of comet particles. Scientific teams around the world have been promised samples and are eagerly awaiting Stardust's return.

Once the capsule is recovered, the UW astronomer and his colleagues will head to NASA's Johnson Space Center in Houston where it will be opened inside a clean room. Some observations could be made within days, but study will go on for years, perhaps decades.

Will Wild 2 provide startling new insights about our origins? Will the dust have more than simple carbon molecules? Could we find more complex biological precursors, say a helical molecule or some other chemical clues as to where we came from?

The Joni Mitchell song "Woodstock," which contains the lyrics "We are stardust" and which, besides being golden, we are "billion-year old carbon," also says:

"I don't know who I am, but you know life is for learning."

"This is when the real science begins," Brownlee said. "And I wouldn't be surprised if what we find includes some surprises."
0 Replies
 
danon5
 
  1  
Reply Sat 7 Jan, 2006 07:25 pm
8 days to wait..... I can BEARLY wait the landing of this BIRD..... I'm like a CAT on a hot Florida beach.

Nice article sumac....... That's interesting stuff.
0 Replies
 
Stradee
 
  1  
Reply Sat 7 Jan, 2006 10:25 pm
Now that is interesting, sumac! Should be quite an exhibition. If the parachute works, then we'll probably have more questions than answers from floating particles <or is the dangling participles> grin

at any rate, will be an interesting study, and Dan - the beaches of Florida are mighty cool this time of year don't ya know - so hold on to yur britches...
0 Replies
 
Stradee
 
  1  
Reply Sat 7 Jan, 2006 10:33 pm
Check out Lake Tahoes Diamond Peak ya all ~

http://lava.nationalgeographic.com/pod/pictures/normal/SP160_50056.jpg
0 Replies
 
danon5
 
  1  
Reply Sun 8 Jan, 2006 07:51 am
I miss snow. It's been in the 70's down here for weeks. This isn't Winter!!!!!

Morning all,

All clicked for Aa, Ma and myself.
0 Replies
 
sumac
 
  1  
Reply Sun 8 Jan, 2006 10:05 am
It certainly looks beautiful. Like everyone in the south, I would like to see that fir a day or so and then have it be gone. But we have the temperatures of winter, which is enough. We have seasons here.
0 Replies
 
sumac
 
  1  
Reply Sun 8 Jan, 2006 11:08 am
http://www.nytimes.com/2006/01/08/opinion/08powers.html?th&emc=th

Nice companion piece to Mozart skull identity, being announced today in Vienna.
0 Replies
 
ehBeth
 
  1  
Reply Sun 8 Jan, 2006 01:11 pm
g'day all !!!

we've got some very nice snow right now ... but it's supposed to melt again Confused

~~~~~~~~~~~

clicked for the aktbird, devriesj and my sub-team

~~~~~~~~~~~

You and your 285 friends have supported 2,179,647.1 square feet!

Marine Wetlands habitat supported: 92,333.0 square feet.
You have supported: (0.0)
Your 285 friends have supported: (92,333.0)

American Prairie habitat supported: 45,950.0 square feet.
You have supported: (11,307.0)
Your 285 friends have supported: (34,643.1)

Rainforest habitat supported: 2,041,364.0 square feet.
You have supported: (167,887.8)
Your 285 friends have supported: (1,873,476.3)

~~~~~~~~~~~

1 Aktbird57 .. 1335 50.034 acres
0 Replies
 
danon5
 
  1  
Reply Sun 8 Jan, 2006 06:25 pm
Wow.......

Still can't believe we have clicked OVER 50 acres....

ehBeth, Have you told Andrew Keith about it ??

He may be surprised.
0 Replies
 
ehBeth
 
  1  
Reply Sun 8 Jan, 2006 06:29 pm
danon - the aktbird57 would have received the same note, and link to this thread, that the other wildclickers did - since he's been clicking daily through that account, I have to hope he read the message.
0 Replies
 
 

Related Topics

 
Copyright © 2025 MadLab, LLC :: Terms of Service :: Privacy Policy :: Page generated in 0.04 seconds on 01/08/2025 at 12:20:25