Category Archives: Evolution

Your Microbiome

Microorganisms from a Human Mourh
Microorganisms from a Human Mouth, Magnified About a Zillion Times
How many cells make up your body? It’s actually not all that easy to answer that simple question. But recently, scientists have made a pretty good effort. And their final count is…37.2 trillion.
October 24, 2013

 

You know that your body is made up of cells. Right? But 37 trillion of them! Who could have guessed? And now that we know, what does it really mean? How many is 37 trillion, anyway? And how did they come up with this number in the first place?

Estimate based on volume, and you get only 15 trillion cells; by weight, you get 70 trillion cells. Unfortunately, nobody has actually counted them all yet. (I wonder why?)

They divided the body into parts and estimated the number of cells in each part, from intestines to knees. This works better because cells are packed more densely in some organs than others.

The smallest cell in the human body is the sperm; the largest, the egg. The ostrich lays the largest egg of any living bird, weighing up to 3.3 lb and measuring up to 7.0 in × 5.5 in; but the largest cell on the planet is probably the egg of the whale shark, measuring up to 11.8 in × 5.5 in × 3.5 in. That’s one big cell!

But I haven’t even mentioned your microbiome yet. That consists of all the single-celled bacteria, archaea, fungi, and protists that live and make their living on and in your body. The generally accepted figure is that there are ten times more microbes living on and in you than there are of your own human cells in your own human body.

Blood Cells
Blood Cells

This is possible because a human cell can easily have 1,000 times the volume of a bacterial cell, for example. Again, nobody ever sat down one afternoon and counted them. It’s an estimate.

So that’s 372 trillion critters crawling, swimming, and otherwise making their ways around your body, or just sitting still. Many of them are essrntial to your own health. A few are harmful and any number of them may be neutral, neither harming or hurting you. There are so many and they are so tiny and hard to study that it’ll be a long, long time before all that gets sorted out.

So how many is 372 trillion? It’s 372,000,000,000,000. If they were minutes into the past, no animal or plant life had evolved on earth yet. Your ancestors and mine were teensy, tiny, single-celled creatures not terribly different from an amoeba.

If these 372 trillion microbes were inches, they’d reach more than half-way across the galaxy. Any way you look at it, that;s a lot of bugs! All on you.

Wash your hands before you eat.

Sources:

_______________________________________________

Kakapo Joy

No wonder the kakapo is the most endangered parrot in the world!

The kakapo here trying to copulate with a man’s head is Sirocco. His species of large, flightless, nocturnal, ground-dwelling parrots endemic to New Zealand is critically endangered because of humans, but not for the reason you may be thinking.

After New Zealand broke off from the supercontinent  Gondwana, around 82 million years ago, any major predators on it became extinct. Among other creatures that survived were a population of parrots, which eventually evolved into several species, including the kakapo.

There were several species of hawk and an owl that occasionally preyed on the kakapo. but nothing on the ground. Even the avian predators are extinct now, except for two species of hawk. The giant Haast’s eagle died out when humans hunted its main prey, the giant moa, another flightless bird which could reach up to twelve feet tall, to extinction.

The bird was of high value to the Maori, who arrived in New Zealand in several waves of canoe voyages beginning about 1250 a.d., bringing with them the rats and other vermin that accompany humans everywhere. They hunted the birds for meat and for their beautiful feathers and sometimes kept them as pets.

Sirocco
Sirocco the Kakapo

Then European settlers came in the seventeenth century, bringing dogs, cats, foxes, ferrets and other beasts that go feral and devour the native fauna and flora. The flightless, ground-nesting birds didn’t have a chance!

The Europeans also hunted them for meat and kept
them as pets. One settler wrote that his kakapo’s behavior toward him and his friends was “more like that of a dog than a bird”.

New Zealand has no native non=marine mammals except bats, for the obvious reason that bats flew there and other mammals couldn’t. Why did they? I dunno. Maybe they got lost. Maybe a storm blew them off course from wherever they intended to go.

Birds often lose the power of flight and grow larger on islands with no predators to escape from, and this is what happened to the kakapo. It’s the largest parrot on earth and accumulates masses of body fat, but it didn’t need to fly until humans came with their vermin. Since there were no predators, it also nested on the ground. Big mistake!

After the Polynesian and European colonizations, the kakapo was almost wiped out. Now, all surviving kakapos are kept on three predator-free islands, where they are closely monitored. Two large islands have been the subject of large-scale ecological restoration to create self-sustaining ecosystems with suitable habitats for the kakapo. As of April 2018, there were 149 known adult kakapos.

Sources:
______________________________

The Great Tree of Life

From VisuallyThe Great Tree of Life.

The “Tree of Life,” which shows relationships among all forms of life to the extent we know them, is no longer a tree. It has taken the form of an arc with many thick branches. On seeing it depicted this way, one is inclined to remember Charles Darwin’s words:

It is interesting to contemplate an entangled bank, clothed with many plants of many kinds, with birds singing on the bushes, with various insects flitting about, and with worms crawling through the damp earth, and to reflect that these elaborately constructed forms, so different from each other, and dependent on each other in so complex a manner, have all been produced by laws acting around us (the laws of nature).

Sources:
_________________
On the Origin of Species (First Edition), by Charles Darwin

Happy Birthday, Richard Dawkins

Richard Dawkins
Richard Dawkins

On this date in 1941, evolutionary biologist and freethought champion Richard Dawkins was born in Nairobi. His father had moved to Kenya from England during the Second World War to join the Allied Forces and the family returned to England in 1949.

Dawkins graduated from Oxford in 1962, earned his doctorate, became assistant professor of zoology at the University of California at Berkeley 1967-1969 and a fellow of New College in 1970.

The Selfish Gene, his first book, published in 1976, became an international bestseller. It and the award-winning Blind Watchmaker were translated into all major languages.

His other books include The Extended Phenotype (1982), River Out of Eden (1995), Climbing Mount Improbable (1996), Unweaving the Rainbow (1998) and A Devil’s Chaplain (2003). His 2006 iconoclastic book, The God Delusion, which he wrote with the public hope of turning believing readers into atheists, became a bestseller in both the UK and the U.S.

Dawkins has held the Charles Simonyi Chair of Public Understanding of Science since 1995, and was elected a Fellow of the Royal Society of Literature in 1997. He is married to actress and artist Lalla Ward, who has illustrated several of his books and other works.

Dawkins has advanced the concept of cultural inheritance or “memes,” also described as “viruses of the mind,” a category into which he places religious belief. He has also advanced the “replicator concept” of evolution.

A passionate atheist, Dawkins has coined the memorable term “faith-heads” to describe certain religionists. Since his remarks in The Guardian (Feb, 6, 1999): “I’m like a pit bull terrier being released into the ring, as a spectator sport, to attack religious people . . .,” Dawkins is now affectionately known as “Darwin’s pit bull.”

Dawkins, a vice president of the British Humanist Association, was named Humanist of the Year in 1999. He is the 1997 winner of the International Cosmos Prize, and received an Emperor Has No Clothes Award from the Freedom From Religion Foundation in 2001. His column for The Observer (“Children Must Choose Their own Beliefs,” Dec. 30, 2001) pointed out: “We deliberately set up, and massively subsidise, segregated faith schools (Note: In the UK, where he lives). As if it were not enough that we fasten belief-labels on babies at birth, those badges of mental apartheid are now reinforced and refreshed. In their separate schools, children are separately taught mutually incompatible beliefs.”

Following the terrorist attacks of Sept. 11, 2001, he eloquently warned in a Guardian column, “Religion’s Misguided Missiles” (Sept. 15, 2001): “To fill a world with religion, or religions of the Abrahamic kind, is like littering the streets with loaded guns. Do not be surprised if they are used.”

Photo by David Shinbone under CC 3.0

“My respect for the Abrahamic religions went up in the smoke and choking dust of September 11th. The last vestige of respect for the taboo disappeared as I watched the ‘Day of Prayer’ in Washington Cathedral, where people of mutually incompatible faiths united in homage to the very force that caused the problem in the first place: religion. It is time for people of intellect, as opposed to people of faith, to stand up and say ‘Enough!’ Let our tribute to the dead be a new resolve: to respect people for what they individually think, rather than respect groups for what they were collectively brought up to believe.

—-“Time to Stand Up,” written for the Freedom From Religion Foundation, Sept. 2001. See Dawkins’s Emperor Has No Clothes Award

Compiled by Annie Laurie Gaylor

© Freedom From Religion Foundation. All rights reserved.

– See more at: http://ffrf.org/news/day/26/03/freethought/#richard-dawkins

Be wary of this man.

blame I think this may be the guy I wrote about yesterday. Remember? The one who said, “God is watching over us” while eleven people died? Be wary of this man.

I just found this guy’s picture on Facebook and thought I ought to post it here, because you probably know him. If not, you almost certainly know somebody like him.

He’s conservative; he probably votes Republican, though he’ll tell you he’s politically independent; and he thinks the United States is a Christian nation, even though our Constitution never mentions Christ. He loves sinners–well, except maybe faggots and godless, atheistic secular humanists–and wants to save them from themselves and the world from them. He honors the presidency of the United States, but despises our President; and he loves our country so much he wants to tear up the Constitution and establish a theocracy. By force, if necessary.

He’ll tell you climate change is “the biggest fraud ever perpetrated against the American people,” even as we complete the hottest year in the history of climate studies. He’ll lie to your face and claim it’s not true that 13 of the 14 hottest years on record have been since the turn of this century and the other one was 1998. He’ll laugh about the possibility that sea level could rise enough to notice, even while small island nations prepare to be swallowed up by the waves.

He’ll say that “if you tell your kids they came from animals, they’ll act like animals.” Then he’ll claim we were all made out of dirt.

This man is a Fundamentalist. What makes him dangerous is not just that he’s so wrong about so many things, but that he’s absolutely certain he is right about them. Ask him what could potentially shake his faith in his beliefs and he’ll probably answer truthfully, “Absolutely nothing.” He is so certain, in fact, that he wants you to live your life according to the dictates of his conscience.

Saudi Arabia is ruled by men just as certain of their wrong ideas. Iran is ruled by men just as certain of their wrong ideas. North Korea is ruled by a man just as certain of his wrong ideas. America needs leaders who get their ideas and ideals from science and reason and compassion, and who understand they might be wrong about anything they believe and willing to learn better.

Be wary of this man. Be very wary of this man

____________________________________

Sources:

Genetics and Evolution Classes Online

What Is Evolution? with Mohamed Noor, Earl D. McLean Professor and Chair of the Biology Department of Duke University.

Professor Noor is an avid researcher into complex areas of evolution, hybridization, and genetics. He is known for (among other things) helping develop “a model wherein regions of restricted recombination, as by chromosomal inversions, facilitate the persistence of hybridizing species.” In 2008, he was awarded the Darwin-Wallace Medal from the Linnean Society of London.

He has served as editor for the international journal Evolution and associate editor for several other journals, as well as authoring over 100 publications. He has served as president of the American Genetic Association and Society for the Study of Evolution and as a board member for the Genetics Society of America.

Genetics and Evolution Classes

Noor and his group have also developed laboratory activities for high schools and colleges and a commercial kit for observing natural selection in Drosophila.He  has been active in education and outreach, receiving numerous teaching and mentoring awards from his institution, and more recently teaching online genetics and evolution classes.

This is the first lesson of that course, and it leads directly to the whole series of classes. For people with a desire to understand basic genetics and evolution, watching these videos is an excellent way to learn.


Sources:

What Controversy?

http://carbon-comic.com/

No Controversy

The cartoonist notes:

With the heightened political coverage, the ridiculous anti-science popping up in my newsfeed is reaching frustrating levels. Yes, I’m talking about you, Texas.

Do your part in the fight for science literacy and buy a copy of Sounds Sciencey for a friend!

Anyway, keep calm and science on!

Texas is my state. Most of the time, I’m proud  to be a Texan. But I know that Dallas Independent School District and many others are teaching creationism and Intelligent Design in biology classes, I have to hang my head.

No controversy!

There is no controversy among scientists. The controversy is all among politicians and certain religious people. Evolution is real and should be taught in public school biology classes. Creationism and intelligent design are phony and should not be taught. It’s as simple as that?

97% of all scientists accept evolution as the way we and other living things got here, and far more than 99% of scientists working in biological fields. There is no controversy among them!

Women’s rights, too

When I read how our state legislature has restricted women’s reproductive rights in the last couple of years, my head hangs even further. In some ways, we haven’t progressed in the last and 65 years.

Science and women’s rights don’t necessarily go together, but they’re both important. Extremely important! Fellow Texans, we need to build a fire under our governor and our legislature and force them into the 21st-century.

In varying degrees, the same is true of the other states in our country and of our federal government. America can be great again, but not this way.


Source:

Kimbetopsalis simmonsae: Newly discovered mammal species survived dinosaur extinction

reconstruction of Kimbetopsalis simmonsae

Kimbetopsalis simmonsae discovered

Paleontologists recently found a species of mammal that survived the extinction of the dinosaurs and named it Kimbetopsalis simmonsae, meaning “Simmon’s cutting shears of Kimbeto Wash,” in honor of the scientist who found the fossils, the place where they were found, and the snipping front teeth of the beast.

The deadly asteroid almost six miles across struck the earth at several tens of thousands of miles per hour, producing a greater explosive force than a billion Hiroshima bombs and creating worldwide earthquakes and tsunamis. About the same time, huge lava flows in and around India (maybe also caused by the impact) filled the atmosphere with suffocating and poison gasses. Fires started by the impact and its ejecta and by the lava spread around the planet, filling the air with particulates and more gasses. Particles blocked the sun, cooling the world and cutting off photosynthesis for years. Over half of all life on Earth was wiped out.

Plants that were not destroyed in the initial cataclysm died from cold and lack of sunshine. Animal herbivores starved without plants to feed upon. Carnivores starved without herbivores to feed upon. Within probably a year, most life on earth had died. Before it was over, all non-avian dinosaurs and three quarters of earth’s other species were extinct.

It was not a good time to be alive, and most species made a swift exit from the global stage: Vegetation withered. Ocean life gasped for air and energy, then collapsed. Gone were the fearsome Tyrannosaurus, the winged Pterosaurs, the massive Triceratops with its three horns and bony neck frill. The dinosaurs’ 100 million-year reign had ended. And when the smoke cleared, a new hero had taken over.

Washington Post

That new “hero” was the mammal.

Kimbetopsalis simmonsae, the newly discovered species, was a plant-eating mammal that resembled a beaver. More specifically, it was a multituberculate, a superficially rodent-like order of extinct mammals named for the numerous cusps, or tubercles, found on their teeth. They lived another 30 million years after the extinction.

Those teeth may have been their secret of success in the wake of the mass-extinction. The anatomy of their jaws gave them “a grinding-focused chewing stroke,” according to the report. Together with their snipping incisor teeth, these allowed them to eat a large variety of whatever vegetation was available.

This particular species lived about 64.5 million years ago in what is now the San Juan Basin of northern New Mexico. Estimated at around three feet long and over 22 pounds. That’s quite large when one considers that most mammals living in the age of dinosaurs were about the size of a mouse.

The world had been wrecked. An asteroid impact in Mexico compounded by colossal volcanism in India 66 million years ago had killed about three-quarters of Earth’s species including the dinosaurs.

But relatively soon afterward, a plucky critter that looked like a beaver was thriving, exemplifying the resilience of the mammals that would arise from the margins of the animal kingdom to become Earth’s dominant land creatures.

Scientists on Monday announced the discovery in northwestern New Mexico’s badlands of the fossil remains of Kimbetopsalis simmonsae, a plant-eating, rodent-like mammal boasting buck-toothed incisors like a beaver that lived just a few hundred thousand years after the mass extinction, a blink of the eye in geological time.

Kimbetopsalis, estimated at 1 metre, would have been covered in fur and possessed large molar teeth with rows of cusps used to grind down plants.

Asked what someone’s impression of Kimbetopsalis might be, New Mexico Museum of Natural History and Science curator of paleontology Thomas Williamson said, “They would probably think something like, ‘Hey, look at that little beaver! Why doesn’t it have a flat tail?”

Stuff.co.NZ

Dr Stephen Brusatte from the University of Edinburgh told how Carissa Raymond, a student on his team, found the fossils of Kimbetopsalis simmonsae while prospecting at a site in New Mexico. The Zoological Journal of the Linnean Society published it.

While Earth’s ecosystems struggled to recover from the catastrophe, New Mexico became a lush area of forests, rivers, streams and lakes. Kimbetopsalis grew from the size of a mouse to the size of a very large beaver over the course of just 500,000 years — a mere blink of an eye in evolutionary terms. It had a beaver’s broad face and chunky frame, but probably no paddle-like tail. It is known from a partial skull and parts of the upper jaws, including teeth still in their sockets.

Mammals originated from early dinosaurs.

 jaws of Kimbetopsalis simmonsae

Mammals had originated about the same time as the dinosaurs got their start; but nearly all of them remained very small until the dinosaurs were superseded by rodents. With the “terrible lizard” predators gone, they were finally free to grow larger without being eaten.

Multituberculates were one of evolution’s greatest success stories. That may seem odd to say now, being that they’ve been extinct for over 30 million years, but that’s why a Deep Time perspective is essential to comprehending Life. As New Mexico Museum of Natural History and Science paleontologist Thomas Williamson and colleagues write at the top of their latest paper on the beasts, multituberculates originated and thrived while the dinosaurs still gripped the world in their claws, survived the mass extinction at the end of the Cretaceous, and again proliferated during the “Age of Mammals” for tens of millions of years before finally expiring. And thanks to some pieces of skull found in northern New Mexico, Williamson and colleagues have identified one of the pioneering “multis” that evolved soon after the dinosaurs had global dominance wrested from them.

National Geographic (Phenomena:Laelaps)

The mass extinction not only killed all the dinosaurs except for the specific lineage that was already evolving into birds; it also devastated the world’s biodiversity. But it gave mammals an opportunity to quickly fill the niches left by the reptiles, and for a particular group of them to evolve into you and me.


Sources:

Dawkins Debunked? Guess Again!

Professor Richard Dawkins is highly respected worldwide as a scientist, an outspoken atheist, and author of The Selfish Gene, The God Delusion, and a dozen or so other best-selling books about biology, biography, and atheism. On February 13, 2009, he was part of a team of scientists invited to take part in the dissection of a giraffe’s neck to study its recurrent laryngeal nerve. Such a dissection had been done on a giraffe only once before that we have record of, in 1838. So it was good to be able to do it again on a giraffe that had died in a  zoo.

As expected, this nerve — two nerves actually; one on each side — was found to go from the animal’s brain all the way down its long neck to the area of its its heart, just missing the larynx by about an inch. Then it wrapped around a major artery (a different on one each side), and ran back up to control the larynx at the top of the neck. Altogether, the nerve is about 15 feet longer than necessary, which exposes it to a variety of unnecessary dangers.

Dawkins says we expect imperfections from evolution.

Dawkins points out that this is exactly the kind of thing we expect from evolution, and he explains why. The giraffe inherited its incredibly long nerves from its fish ancestors, where the arrangement was practical because fish have no necks.  As fish morphed into amphibians, then reptiles, and finally birds and mammals, the arrangement became less and less practical. But evolution can’t change something like that just because it’s no longer the best arrangement; evolution has to work with what it has. When a problem is serious enough, it can lead to the extinction of a species. This is one reason why an estimated 99% (at least) of all species that ever lived live no more.

Dawkins points out several reasons why no intelligent designer would have created the giraffe that way. It’s the kind of thing one would only expect to find if evolution were true, as it is.

In the video below, Rick Gerhardt, who is both a conservation biologist and a Christian apologist, discusses Dawkins’ video and tries pitifully to debunk it. He specializes in avian ecology and has special interests also in beetles and snakes. The kinds of of arguments he makes here don’t sound like a scientist of any kind, but they sound exactly like the kinds of arguments I read from ignorant creationists all the time.

You be the judge. I say, “Shame on Rick Gerhardt for trying to debunk good science.”

__________________________________

Sources: