Human evolution, fire and smoke


This video says about itself:

Smoking Causes Cancer, Heart Disease, Emphysema

20 jul. 2012

This 3D medical animation created by Nucleus Medical Media shows the health risks of smoking tobacco.

ID#: ANH12071

Transcript:

Every time you smoke a cigarette, toxic gases pass into your lungs, then into your bloodstream, where they spread to every organ in your body. A cigarette is made using the tobacco leaf, which contains nicotine and a variety of other compounds. As the tobacco and compounds burn, they release thousands of dangerous chemicals, including over forty known to cause cancer. Cigarette smoke contains the poisonous gases carbon monoxide and nitrogen oxide, as well as trace amounts of cancer-causing radioactive particles. All forms of tobacco are dangerous, including cigars, pipes, and smokeless tobacco, such as chewing tobacco and snuff.

Nicotine is an addictive chemical in tobacco. Smoking causes death. People who smoke typically die at an earlier age than non-smokers. In fact, 1 of every 5 deaths in the United States is linked to cigarette smoking.

If you smoke, your risk for major health problems increases dramatically, including: heart disease, heart attack, stroke, lung cancer, and death from chronic obstructive pulmonary disease.

Smoking causes cardiovascular disease.

When nicotine flows through your adrenal glands, it stimulates the release of epinephrine, a hormone that raises your blood pressure. In addition, nicotine and carbon monoxide can damage the lining of the inner walls in your arteries. Fatty deposits, called plaque, can build up at these injury sites and become large enough to narrow the arteries and severely reduce blood flow, resulting in a condition called atherosclerosis. In coronary artery disease, atherosclerosis narrows the arteries that supply the heart, which reduces the supply of oxygen to your heart muscle, increasing your risk for a heart attack. Smoking also raises your risk for blood clots because it causes platelets in your blood to clump together. Smoking increases your risk for peripheral vascular disease, in which atherosclerotic plaques block the large arteries in your arms and legs. Smoking can also cause an abdominal aortic aneurysm, which is a swelling or weakening of your aorta where it runs through your abdomen.

Smoking damages two main parts of your lungs: your airways, also called bronchial tubes, and small air sacs called alveoli. Cigarette smoke irritates the lining of your bronchial tubes, causing them to swell and make mucus. Cigarette smoke also slows the movement of your cilia, causing some of the smoke and mucus to stay in your lungs. While you are sleeping, some of the cilia recover and start pushing more pollutants and mucus out of your lungs. When you wake up, your body attempts to expel this material by coughing repeatedly, a condition known as smoker’s cough. Over time, chronic bronchitis develops as your cilia stop working, your airways become clogged with scars and mucus, and breathing becomes difficult.

Your lungs are now more vulnerable to further disease. Cigarette smoke also damages your alveoli, making it harder for oxygen and carbon dioxide to exchange with your blood. Over time, so little oxygen can reach your blood that you may develop emphysema, a condition in which you must gasp for every breath and wear an oxygen tube under your nose in order to breathe.

Chronic bronchitis and emphysema are collectively called chronic obstructive pulmonary disease, or COPD. COPD is a gradual loss of the ability to breathe for which there is no cure.

Cigarette smoke contains at least 40 cancer-causing substances, called carcinogens, including cyanide, formaldehyde, benzene, and ammonia. In your body, healthy cells grow, make new cells, then die. Genetic material inside each cell, called DNA, directs this process. If you smoke, toxic chemicals can damage the DNA in your healthy cells. As a result, your damaged cells create new unhealthy cells, which grow out of control and may spread to other parts of your body. Cigarettes can cause cancer in other parts of your body, such as: in the blood and bone marrow, mouth, larynx, throat, esophagus, stomach, pancreas, kidney, bladder, uterus, and cervix.

Smoking can cause infertility in both men and women. If a woman is pregnant and smokes during pregnancy, she exposes her baby to the cigarette’s poisonous chemicals, causing a greater risk of: low birth weight, miscarriage, preterm delivery, stillbirth, infant death, and sudden infant death syndrome. Smoking is also dangerous if a mother is breastfeeding. Nicotine passes to the baby through breast milk, and can cause restlessness, rapid heartbeat, vomiting, interrupted sleep, or diarrhea.

Other health effects of smoking include: low bone density and increased risk for hip fracture among women; gum disease, often leading to tooth loss and surgery; immune system dysfunction and delayed wound healing; and sexual impotence in men.

From Leiden University in the Netherlands:

Are modern humans simply bad at smoking?

Published on 21 September 2016

Scientists looked for the genetic footprint of fire use in our genes, but found that our prehistoric cousins – the Neanderthals – and even the great apes seem better at dealing with the toxins in smoke than modern humans.

Mixed blessing

The art of making and using fire was one of the greatest discoveries ‘ever made by man’, wrote Charles Darwin. Besides providing protection against cold temperatures, the use of fire in food preparation and the introduction of energy-rich cooked foods in our prehistoric diet had a major impact in the development of humankind. However, fire use comes at a cost. Exposure to the toxic compounds in smoke carries major risks for developing pneumonia, adverse pregnancy outcomes in women and reduced sperm quality in males, as well as cataracts, tuberculosis, heart disease, and chronic lung disease. In short, the use of fire is a mixed blessing.

Debate

This mixed blessing, however, put researchers at Leiden University and Wageningen University on the trail of finding genetic markers for the use of fire in prehistoric and recent humans. The use of fire is notoriously difficult to ‘see’ for archaeologists, and this has led to strong disagreement over the history of its usage. A very early start is advocated by Harvard primatologist Richard Wrangham, who argues that our Homo erectus ancestors were already using fire around two million years ago. However, numerous excavations and intensive research carried out by archaeologists in Europe and the Near East suggest that control of fire occurred much later, around 350,000 years ago.

Genetic markers for fire use

In order to bring fresh data into this ‘hot’ debate, the Leiden/Wageningen team studied the biological adaptations of prehistoric and recent humans to the toxic compounds of smoke: fire usage implies frequent exposure to hazardous compounds from smoke and heated food, which is expected to result in the selection of gene variants conferring an improved defence against these toxic compounds. To study whether such genetic selection indeed occurred, the team investigated the gene variants occurring in Neanderthals, in Denisovans (contemporaries of the Neanderthals, more related to them than to modern humans), and in prehistoric modern humans.

Tobacco

Single nucleotide variants in 19 genes were tested that are known from modern tobacco-smoking studies to increase the risk of fertility and reproduction problems when exposed to smoke and hazardous compounds formed in heated food.

These genes were compared with variants observed in Neanderthals and their Denisovan cousins, and were also studied in chimpanzees and gorillas, two closely related species that are obviously not using fire, and are therefore not exposed to smoke on a regular basis.

Neanderthal more efficient in handling smoke?

In a study now published in PLOS ONE, the team shows that Neanderthals and the Denisovan predominantly possessed gene variants that were more efficient in handling the toxic compounds in smoke than modern humans. Surprisingly, these efficient variants were also observed in chimpanzees and gorillas, and therefore appeared to be evolutionary very old (ancestral) variants.

Plant toxins

The less efficient variants are observable from the first modern human hunter-gatherers for which we have genetic information onward, i.e. from about 40,000 years ago. The efficient defence against toxic compounds in chimpanzees and gorillas may be related to the toxins in their plant food. Smoke defence capacities in humans apparently hitchhike on those adaptations, developed deep in our primate past. Our prehistoric ancestors were probably already good at dealing with the toxic compounds of smoke, long before they started producing it through their campfires. What allowed for the emergence of less efficient hazardous chemical defence genes in modern humans is a question for future research.

Ancient Indian primates discovered


This video is called 54 Million Year Old Fossils Point To India As Key In Primate Evolution.

From Science News:

Fossils hint at India’s crucial role in primate evolution

Limb bones may reveal what common ancestor looked like

By Bruce Bower

9:00am, September 8, 2016

Remarkably preserved bones of rat-sized creatures excavated in an Indian coal mine may come from close relatives of the first primatelike animals, researchers say.

A set of 25 arm, leg, ankle and foot fossils, dating to roughly 54.5 million years ago, raises India’s profile as a possible hotbed of early primate evolution, say evolutionary biologist Rachel Dunn of Des Moines University in Iowa and her colleagues. Bones from Vastan coal mine in Gujarat, India’s westernmost state, indicate that these tiny tree-dwellers resembled the first primates from as early as 65 million years ago, the scientists report in the October Journal of Human Evolution.

These discoveries add to previously reported jaws, teeth and limb bones of four ancient primate species found in the same mine. “The Vastan primates probably approximate a common primate ancestor better than any fossils found previously,” says paleontologist and study coauthor Kenneth Rose of Johns Hopkins University School of Medicine.

The Vastan animals were about the size of living gray mouse lemurs and dwarf lemurs, weighing roughly 150 to 300 grams (roughly half a pound), the investigators estimate. Dunn’s group has posted 3-D scans of the fossils to Morphosource.org (SN: 3/19/16, p. 28) so other researchers can download and study the material.

Most Vastan individuals possessed a basic climbing ability unlike the more specialized builds of members of the two ancient primate groups that gave rise to present-day primates, the researchers say. One of those groups, omomyids, consisted of relatives of tarsiers, monkeys and apes. The other group, adapoids, included relatives of lemurs, lorises and bushbabies. The Indian primates were tree-dwellers but could not leap from branch to branch like lemurs or ascend trees with the slow-but-sure grips of lorises, the new report concludes.

Vastan primates probably descended from a common ancestor of omomyids and adapoids, the researchers propose. India was a drifting landmass headed north toward a collision with mainland Asia when the Vastan primates were alive. Isolated on a huge chunk of land, the Indian primates evolved relatively slowly, retaining a great number of ancestral skeletal traits, Rose suspects.

“It’s possible that India played an important role in primate evolution,” says evolutionary anthropologist Doug Boyer of Duke University. A team led by Boyer reported in 2010 that a roughly 65-million-year-old fossil found in southern India might be a close relative of the common ancestor of primates, tree shrews and flying lemurs (which glide rather than fly and are not true lemurs).

One possibility is that primates and their close relatives evolved in isolation on the island continent of India between around 65 million and 55 million years ago, Boyer suggests. Primates then spread around the world once India joined Asia by about 50 million years ago.

That’s a controversial idea. An increasing number of scientists suspect primates originated in Asia. Chinese primate fossils dating to 56 million to 55 million years ago are slightly older than the Vastan primates (SN: 6/29/13, p. 14; SN: 1/3/04, p. 4). The Chinese finds show signs of having been omomyids.

And in at least one respect, Boyer says, some of the new Vastan fossils may be more specialized than their discoverers claim. Vastan ankle bones, for instance, look enough like those of modern lemurs to raise doubts that the Indian primates were direct descendants of primate precursors, he holds.

Dunn, however, regards the overall anatomy of the Vastan fossils as “the most direct evidence we have” that ancestors of early primates lacked lemurs’ leaping abilities, contrary to what some researchers have argued.

Madagascar dwarf lemurs, sleep and hibernation


This video from the USA says about itself:

2 May 2013

Two new species of dwarf lemurs have been found hibernating during the lean months of winter in Eastern Madagascar. Scientific Reports, May 2, 2013. An interview with researcher Marina Blanco, PhD, with footage from field research and still images from the Duke Lemur Center. See story here.

From Science News:

Dwarf lemurs don’t agree on sleep

Fat-tailed species dozes during hibernation, but latest tests find different twist in relatives

By Susan Milius

10:00am, September 5, 2016

Contrary to many adorable children’s stories, hibernation is so not sleeping. And most animals can’t do both at the same time.

So what’s with Madagascar’s dwarf lemurs? The fat-tailed dwarf lemur slows its metabolism into true hibernation, and stays there even when brain monitoring shows it’s also sleeping. But two lemur cousins, scientists have just learned, don’t multitask. Like other animals, they have to rev their metabolisms out of hibernation if they want a nap.

Hibernating animals, in the strictest sense, stop regulating body temperature, says Peter Klopfer, cofounder of the Duke Lemur Center in Durham, N.C. “They become totally cold-blooded, like snakes.” By this definition, bears don’t hibernate; they downregulate, dropping their body temperatures only modestly, even when winter den temperatures sink lower. And real hibernation lasts months, disqualifying short-termers such as subtropical hummingbirds. The darting fliers cease temperature regulation and go truly torpid at night. “You can pick them out of the trees,” Klopfer says.

The fat-tailed dwarf lemur, Cheirogaleus medius, was the first primate hibernator discovered, snuggling deep into the softly rotting wood of dead trees. “You’d think they’d suffocate,” he says. But their oxygen demands plunge to somewhere around 1 percent of usual. As trees warm during the day and cool at night, so do these lemurs. When both a tree and its inner lemur heat up, the lemur’s brain activity reflects mammalian REM sleep.

Klopfer expected much the same from two other dwarf lemurs from an upland forest with cold, wet winters. There, C. crossleyi and C. sibreei spend three to seven months curled up underground, below a thick cushion of fallen leaves. “If you didn’t know better, you might think they were dead because they’re cold to the touch,” Klopfer says.

Unlike the tree-hibernators, the upland lemurs take periodic breaks from hibernating to sleep, Klopfer, the Lemur Center’s Marina Blanco and colleagues report in the August Royal Society Open Science. The lemurs generated some body heat of their own about once a week, which is when their brains showed signs of sleep (REM-like and slow-wave).  “My suspicion is that sleep during torpor is only possible at relatively high temperatures, above 20º Celsius,” Klopfer says. Sleep may be important enough for cold-winter lemurs to come out of the storybook “long winter’s nap.”

Ancient hominin Lucy died by fall from tree


This video says about itself:

Lucy fell from a tree 3.18 million years ago

29 August 2016

Lucy died after falling from a tree, new research suggests. Lucy is a 3.18-million-year-old specimen of Australopithecus afarensis considered one of the oldest and most complete fossil hominins, an erect-walking human ancestor.

From Nature:

Perimortem fractures in Lucy suggest mortality from fall out of tall tree

Published online 29 August 2016

The Pliocene fossil ‘Lucy’ (Australopithecus afarensis) was discovered in the Afar region of Ethiopia in 1974 and is among the oldest and most complete fossil hominin skeletons discovered.

Here we propose, on the basis of close study of her skeleton, that her cause of death was a vertical deceleration event or impact following a fall from considerable height that produced compressive and hinge (greenstick) fractures in multiple skeletal elements. Impacts that are so severe as to cause concomitant fractures usually also damage internal organs; together, these injuries are hypothesized to have caused her death.

Lucy has been at the centre of a vigorous debate about the role, if any, of arboreal locomotion in early human evolution. It is therefore ironic that her death can be attributed to injuries resulting from a fall, probably out of a tall tree, thus offering unusual evidence for the presence of arborealism in this species.

Tim White, a paleoanthropologist at the University of California, Berkeley, has studied Lucy and other Australopithecus fossils, and he doesn’t think there is enough evidence to say how Lucy died. “Most, if not all of the breaks appear to be the result of geological processes well after the time of death,” he tells NPR’s Christopher Joyce. “Fossilization makes bones brittle, and when fossils are embedded in sediment they are often cracked, crushed, and distorted”: here.

Fossil autopsy claims Lucy fell from tree. Disputed analysis says early hominid broke multiple bones: here.

Piltdown man hoax perpetrator exposed


This 2014 video is about the Piltdown man fraud.

From daily The Independent in Britain today:

Piltdown hoax: Culprit behind one of history’s greatest ruses finally exposed

Arthur Conan Doyle was even suspected of being the perpetrator

Kate Nelson

The culprit behind one of the greatest scientific hoaxes in history has been found after new forensic techniques revealed his identity.

Between 1912 and 1914, museum palaeontologist Arthur Smith Woodward and solicitor Charles Dawson claimed to have discovered fossils which supposedly showed the link between man and ape.

Known as the Piltdown Man, after the area of Sussex the remains were allegedly found, the discovery fooled even the most eminent scientific minds of the time.

It took more than 40 years to discover the hoax.

The new fossil had an ape-like jaw and brain-case like a modern human.

Mr Dawson claimed to have discovered further evidence at a second site, close to the original, prior to his death in August 1916.

Doubts were immediately raised but many thought the amateur archeologist was incapable of such a sophisticated ruse.

At one point Sir Arthur Conan Doyle, author of Sherlock Holmes, was under suspicion.

Some thought he wanted to mock scientists for ridiculing his spiritualist beliefs.

New research has now revealed that the forgeries were created using a limited number of specimens all constructed using a consistent method – suggesting the perpetrator acted alone.

It is highly likely that an orangutan specimen and at least two human skeletons were used to create the fakes, which are still kept at the Natural History Museum.

The work, which points the finger of suspicion firmly at Mr Dawson, was undertaken by a team led by Liverpool John Moores University and used the latest scientific methods.

Dr Isabelle De Groote, from the university and lead author on the paper which is published in Royal Society Open Science, said: “Although multiple individuals have been accused of producing the fake fossils, our analyses to understand the modus operandi show consistency between all the different specimens and on both sites.

“It is clear from our analysis that this work was likely all carried out by one forger – Charles Dawson.”

DNA analysis found that both the canine tooth planted at the first Piltdown site and the molar from the second probably came from one orangutan.

Holes in the skull bones were filled with dental putty, which was also used to re-set the teeth in the jaw and to reconstruct one of the teeth that fell apart while it was being ground down.

Chris Stringer, human origins expert at the Natural History Museum, said: “Our work shows that a century on, we can add a new chapter to the Piltdown story through new investigative techniques.

“We found surprising evidence that the forger had even removed the molars in order to modify them, and had then replaced them in the jawbone.”

Madagascar lemurs’ love life, video


This video says about itself:

Lemur‘s Scent Attracts Females – Animal Attraction – BBC

24 January 2016

Ring tailed lemurs waft their special scent to attract females, but the very latest science suggest that his scent contains clues to a different strength…

The Madagascan fat-tailed dwarf lemur could hold the secret to human hibernation and mankind’s chances of exploring the deepest reaches of the known universe, according to a team of top neuroscientists: here.

Most threatened primates top 25


This video from the USA is called RED RUFFED LEMURS at DUKE LEMUR CENTER.

From AFP news agency:

Over half of world’s primates on brink of extinction: experts

24 Nov 2015 at 08:55 ET

More than half the world’s primates, including apes, lemurs and monkeys, are facing extinction, international experts warned Tuesday, as they called for urgent action to protect mankind’s closest living relatives.

The population crunch is the result of large-scale habitat destruction — particularly the burning and clearing of tropical forests — as well as the hunting of primates for food and the illegal wildlife trade.

Species long-known to be at risk, including the Sumatran orangutan, have been joined on the most endangered list for the first time by the Philippine tarsier and the Lavasoa Mountains dwarf lemur from Madagascar, scientists meeting in Singapore said.

“This research highlights the extent of the danger facing many of the world’s primates,” leading primatologist Christoph Schwitzer, director of conservation at Bristol Zoological Society in Britain, said in a statement.

“We hope it will focus people’s attention on these lesser known primate species, some of which most people will probably have never heard of.”

This includes the Lavasoa Mountains dwarf lemur — a species only discovered two years ago — and the Roloway monkey from Ghana and Ivory Coast, which experts say “are on the very verge of extinction”.

There are 703 species and sub-species of primates in the world.

Madagascar and Vietnam are home to large numbers of highly threatened primate species, the statement said.

In Africa, the red colobus monkey was under “particular threat”, as were some of South America’s howler monkeys and spider monkeys, it added.

“All of these species are relatively large and conspicuous, making them prime targets for bushmeat hunting,” the statement said.

Russell Mittermeier, chair of the Species Survival Commission of the International Union for Conservation of Nature (IUCN), said he hoped the report would encourage governments to commit to “desperately needed biodiversity conservation measures”.

Mittermeier said ahead of next month’s global climate conference in Paris, there was growing evidence some primate species might play key roles in dispersing tropical forest tree seeds, which in turn “have a critically important role in mitigating climate change”.

Here is the list of the world’s top 25 most endangered primates for 2014-2016 and their estimated numbers remaining in the wild.

The list is compiled by the IUCN, Bristol Zoological Society, International Primatological Society and Conservation International and is updated every two years:

Lavasoa Mountains dwarf lemur — unknown

Lake Alaotra bamboo lemur — about 2,500-5,000

Red ruffed lemur — unknown

Northern sportive lemur — around 50

Perrier’s sifaka — 1,700-2,600

Rondo dwarf galago — unknown but remaining habitat is just 100 square kilometres (40 square miles)

Roloway monkey — unknown but thought to be on the very verge of extinction

Preuss’ red colobus monkey — unknown

Tana River red colobus monkey — 1,000 and declining

Grauer’s gorilla — 2,000-10,000

Philippine tarsier — unknown

Javan slow loris — unknown

Pig-tailed langur — 3,300

Cat Ba langur (golden headed langur) — 60

Delacour’s langur — 234-275

Tonkin snub-nosed monkey — less than 250

Kashmir grey langur — unknown

Western purple-faced langur — unknown

Hainan gibbon — 25

Sumatran orangutan — 6,600

Ka’apor capuchin — unknown

San Martin titi monkey — unknown

Northern brown howler monkey — less than 250 mature animals

Colombian brown spider monkey — unknown

Ecuadorian brown-headed spider monkey — unknown