Are Butterflies Two Different Animals in One? The Death And Resurrection Theory: Krulwich Wonders: NPR

Are Butterflies Two Different Animals in One? The Death And Resurrection Theory

Updated Aug. 2, 2012: We have added an update to this post, which you can find below the original. Click here to read it.

Here’s a dangerous, crazy thought from an otherwise sober (and very eminent) biologist, Bernd Heinrich. He’s thinking about moths and butterflies, and how they radically change shape as they grow, from little wormy, caterpillar critters to airborne beauties. Why, he wondered, do these flying animals begin their lives as wingless, crawling worms? Baby ducks have wings. Baby bats have wings. Why not baby butterflies?

His answer — and I’m quoting him here — knocked me silly.

«[T]he radical change that occurs,» he says, «does indeed arguably involve death followed by reincarnation.»

So he says it again: «[T]he adult forms of these insects are actually new organisms.»

I’m sorry. Maybe I didn’t hear that right .

«In effect, the animal is a chimera, an amalgam of two, where the first one lives and dies . and then the other emerges.»

What he’s saying is, while a moth appears to be one animal, with a wormy start and a flying finish, it’s actually two animals — two in one! We start with a baby caterpillar that lives a full life and then dies, dissolves. There’s a pause. Then a new animal, the moth, springs to life, from the same cells, reincarnated.

According to this theory, long, long ago, two very different animals, one destined to be wormy, the other destined to take wing, accidently mated, and somehow their genes learned to live side-by-side in their descendants. But their genes never really integrated. They are sharing a DNA molecule like two folks sharing a car, except half way through the trip, one driver dissolves and up pops his totally different successor. Driver No. 2 emerges from the body of driver No. 1.

When this theory was first proposed (not by Bernd, but by an English zoologist), eminent scientists scoffed.

Said Duke biologist Fred Nijhout, this idea fits better in «The National Enquirer than the National Academy (of Sciences).» Said paleontologist Conrad Labandiera, «You must be kidding!»

But Donald Williamson, a zoologist from the University of Liverpool in England, wasn’t kidding. And if Bernd Heinrich is now warming to this notion, it’s time to take a closer look at Death And Resurrection in insects.

The Death And Resurrection Cycle?

Many insects begin life as worm-shaped, leggy, tubular thingies that spend lots of time eating. We call them grubs or maggots or caterpillars, and they are programmed by a set of genes that sit in their DNA, spelled out in chemical letters, A, C, T and G.

Notice I’ve put my «caterpillar» instruction genes on the left side of the DNA. The instructions on the right side are, temporarily, silent.

So the caterpillar grows and grows until one day, it spins itself a silk coverlet (a cocoon) or a harder pupa or chrysalis container that dangles off a twig and it goes . well, silent.

This phase is, as Heinrich puts it, «a deathlike intermission.» Inside, these caterpillars shrink, shed their skin, their organs dissolve. Their insides turn to mush. Most of their cells die. But lurking in the goo are a few cells (the so-called adult or «imaginal» cells) that at this moment jump into action, reorganize all the free-floating proteins and other nutrients and turn what was once caterpillar into . here comes the resurrection . a moth!

What’s happened, says Heinrich, is that the caterpillar section of the DNA has been turned off, and the butterfly instructions have been turned on.

«[T]here are indeed two very different sets of genetic instructions at work,» he writes, and this switch, turning «caterpillar» off, turning «butterfly» on, means that «most of one body dies and the new life is resurrected in a new body.»

Two In One

There is no controversy about the mechanics I just described; it’s the explanation that’s new and controversial. The old view was that over millions of years, animals evolved this habit of switching from one set of instructions to the other. The new view is that this is not one animal gradually changing shape, but rather instructions for two different animals sandwiched together and this change is so radical, says Bernd, «with no continuity from one to the next, that the adult forms of these insets are actually new organisms.«

A caterpillar is born and dies; a butterfly is resurrected from its juices.

It’s a stunning idea. (But with all kinds of problems: How to explain two very different creatures from different ancient species «mating»? Usually, they can’t do that. How do you get DNA to not mix, so that the two creatures stay distinct? How do you define «death»?)

But still, I can’t stop thinking about this. If cross-species matings were once possible, who knows what you could die and turn into? Could dandelions dream of becoming spruce trees? Could tadpoles, instead of morphing into frogs, become catfish? This is silly, I know, but radical metamorphoses, from tadpoles to frogs, maggots to flies, grubs to beetles, remain largely mysterious, so new explanations are intriguing, even if they startle. (Especially if they startle.)

On The Other Hand.

By ROBERT KRULWICH

I have a post-script to this blog. Yes, Bernd Heinrich is intrigued by Donald Williamson’s Death and Resurrection thesis, and yes the strangeness of this theory makes it fun to write about. But there is, of course, an alternate possibility: that this idea is just plain wrong. I mentioned that Donald Williamson’s paper was very controversial when it was first published. It still is. A few hours after this post went up, I was sent a critique of Williamson’s work written by two scientists, Michael Hart and Richard Grosberg.

They think there is no credible evidence for this idea of ancient mating between different species, and that, to summarize their view, they think Williamson’s theory is scientifically indefensible. So far, however, Williamson’s original paper has not been retracted, which is what happens when an idea is so off, or so insupportable that it is no longer scientifically plausible. (However another subsequent Williamson paper — describing another possible ancient mating — has been retracted from a different journal.)

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So, what we have here is one of my favorite scientists embracing an idea that a great many other scientists find noxious and wrong. «You must be kidding!» is still the cry from many men and women who do cell and developmental biology for a living. Eventually, somebody’s face will be red. Maybe Bernd’s. Maybe the other guys’. That’s how science works. But I think you should know that wondering about butterflies and moths can get feisty.

Bernd Heinrich discusses death and resurrection in his new book, Life Everlasting, the Animal Way of Death. His descriptions are often very gripping. Several earlier posts, an essay on chalk, another on vultures, came from this book.

www.npr.org

Butterfly Photography: How to Photograph Butterflies

Home » Photography Tutorials » Macro » Butterfly Photography: How to Photograph Butterflies

It is fair to say that bugs and mini-beasts don’t have the same far-reaching photo appeal as other natural subjects. They lack the ‘ahhhh factor’ and interest of things that are feathered or furred. They can also prove difficult to locate, fiddly, and challenging to shoot. However, in frame-filling close-up, insects are actually hugely photogenic. Butterfly photography is easily accessible; you can find subjects to shoot in your own back garden or a local meadow.

Admittedly, some insects are more appealing than others. While ladybirds and dragonflies compete for top spot in the insect world for being most colourful and appealing, there can surely be only one-winner: butterflies.

Small pearl-bordered fritillary (Clossiana selene), Marsland mouth (DWT/CWT), Cornwall/Devon, UK.

Butterflies are fantastically beautiful and photogenic – even fully subscribed insect-phobes can’t help but be seduced by their colour, intricate markings, delicacy and design. There is somewhere in the region of 20,000 species of butterfly worldwide, with fritillaries, swallowtails, blues and skippers being among the better known families. They’ve inhabited almost every type of environment and can migrate large distances – and in large numbers too.

The UK is home to around 60 types of butterfly and now, during summer, is the best time to dust off your macro lens or close-up attachment in order to embark on some butterfly photography. However, they are challenging subjects. To achieve both aesthetically and technically good butterfly images requires good field-craft, knowledge and skill.

Do your research

Just like any other animal, if you wish to get close to butterflies and capture their character, you need to do your homework first. Fail to do your research, and you won’t know when or where to look.

If you wish to target a specific species, study its preferred habitat – for example, does it favour heath, meadowland, unimproved grassland, chalk downland or woodland? Also, what months of the year do adults emerge and what are their larval food-plants?

You need to photograph butterflies soon after they emerge when they are still in pristine condition. The window of opportunity is brief – mistime your visit, and you may need to wait until the following year before you can try again. The Butterfly Conversation is a great source of information and your local branch will list a number of good butterfly-rich sites. However, butterflies can be found almost anywhere and nectar rich gardens are a good place to look for widespread species, like painted lady, small tortoiseshell and red admiral.

Marbled White, Melanargia galathea, backlit and resting on yellow-rattle. Braunton Burrows, Devon, UK. July 2012.

Once you’ve identified a butterfly-rich habitat to visit, you can begin taking photos. Regarding equipment for butterfly photography, I’ve already written about recommended kit and the best lens for macro. In summary, a tele-macro lens is the best choice as it provides a practical working distance from your subject, but you can capture good butterfly shots with any close-up attachment.

Finding your subject for butterfly photography

Butterflies are most active and easiest to locate on warm, still, sunny days. However, they can prove difficult to get close to, being flighty and sensitive to movement.

During daytime, stalking is the best technique. This is when you follow (not chase!) butterflies around, waiting for them to rest, feed or bask. When they do, you need to efficiently move into position – just be mindful of the sun’s position; if you cast your shadow across your subject, you will likely frighten it away. Also, do not disturb adjacent grasses or vegetation, as butterflies are very sensitive to movement.

Unfortunately, during the middle of the day, the light will be harsh and not particularly conducive to photography. Instead, early morning and late evening are the best times for photography, when butterflies are cool and inactive and the quality of light more attractive.

Small pearl-bordered fritillary, Clossiana selene, backlit in late evening sunshine. Boscastle, UK. May 2010.

The majority of my butterfly photography occurs at either end of the day. During summer, this can involve a painfully early start but, being wildlife photographers, we’re fairly accustomed to tiring, unsociable hours, aren’t we?

I now know several nearby nature reserves intimately, so I know exactly where to look for different butterflies – never underestimate the benefits of local knowledge. I look for subjects roosting in tall grasses or on flowers. When they are cooler, butterflies are less likely to fly away and so it is often possible to set-up a tripod. Using a support is hugely advantageous, allowing you to compose and focus with greater precision.

Recommended camera settings for butterfly photography

Depth of field is inherently shallow at higher magnifications, so there is no leeway for error when focusing. However, if you are using a tripod you can focus via LiveView – something I always prefer to do when practical, as I’m able to magnify the live image and manually focus on the butterfly’s head/eyes with unrivaled precision. A tripod also allows you to select a smaller aperture to achieve the depth of field needed, and – if necessary – use a reflector to relieve ugly shadow areas.

Orange Tip Butterfly, Anthocharis cardamines, female resting on bluebell. Lanhydrock woodland, Cornwall. May 2012.

Personally, I usually want my subject to stand out boldly against a nicely diffused, out of focus backdrop, so I will typically opt for the largest aperture possible (lowest f-stop number) that will still generate sufficient focus. Doing so also provides a faster shutter speed.

In fact, these days I regularly increase my ISO to 800 or 1600. Like many of the latest breed of digital SLRs, my Nikon D810 handles noise very well. Using higher ISOs doesn’t significantly affect image quality anymore, but the faster shutter speed helps to ensure sharp results when wind movement is causing problems.

The wind is a big consideration when shooting butterflies – even the slightest breeze can prove hugely problematic. Look at the forecast before you plan your shoot – a wind speed of below 10-15kph (kilometres per hour) is ideal. Not only are insects less active and flighty at either end of the day, but also the sun’s lower position allows you to be more creative with lighting. Personally, I love backlighting and this type of light suits butterflies well, highlighting the translucency of their wings and emphasising shape and form.

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Background choice is also important when shooting butterflies, so explore the background for any distractions – for example, grasses, or ugly highlights. For more information about general macro photography technique, read my article “Introduction to Macro Photography: Technique“.

From a compositional perspective, butterflies can be photographed in many different ways and angles. The most popular is from above when the insect’s wings are open flat. To maximise depth of field, try to keep your camera parallel to its wings – this is because there is only one geometrical plane of complete sharpness, and normally you will want to place as much of your subject in this plane as possible.

Finally, be patient… very patient. When shooting butterflies, be prepared for moments of complete and utter hair-pulling frustration. You wouldn’t believe the number of times a butterfly will disappear into the distance just at the moment you are about to trigger the shutter! However, thanks to subject knowledge, good technique, perseverance and a little lady luck, you will soon be capturing great butterfly images this summer.

www.naturettl.com

Hives (Urticaria & Angioedema)

Hives facts

  • Hives (medically known as urticaria) are red, itchy, raised welts on the skin that appear in varying shapes and sizes; each one characteristically lasts no longer than six to 12 hours.
  • Although hives are very common, their cause is often elusive.
  • Hives can change size rapidly and move around, disappearing in one place and reappearing in other places, often in a matter of hours.
  • Ordinary hives flare up suddenly.
  • Occasionally hives are produced by direct physical stimulation by environmental forces like heat, cold, and sunlight.
  • Treatment of hives is directed at symptom relief until the condition goes away on its own.
  • Antihistamines are the most common treatment for hives.
  • Hives typically are not associated with long-term or serious complications.

Can Stress Cause Hives?

Hives can also develop as a result of sun or cold exposure, infections, excessive perspiration, and emotional stress. The reason why stress seems to precipitate an outbreak of hives in many people is not completely understood but is likely related to the known effects of stress on the immune system. In many cases, the cause of hives in a given individual cannot be identified.

What are hives (urticaria) and angioedema? What do hives look like?

Hives (medically known as urticaria) appear on the skin as wheals that are red, very itchy, smoothly elevated areas of skin often with a blanched center. They appear in varying shapes and sizes, from a few millimeters to several centimeters in diameter anywhere on the body.

It is estimated that 20% of all people will develop urticaria at some point in their lives. Hives are more common in women than in men. One hallmark of hives are their tendency to change size rapidly and to move around, disappearing in one place and reappearing in other places, often in a matter of hours. An individual hive usually lasts no longer than 24 hours. An outbreak that looks impressive, even alarming, first thing in the morning can be completely gone by noon, only to be back in full force later in the day. Very few skin diseases occur and then resolve so rapidly. Therefore, even if you have no evidence of hives to show the doctor when you get to the office for examination, the diagnosis can be established based upon the accurate recounting of your symptoms and signs. Because hives fluctuate so much and so fast, it is helpful to bring along a photograph of what the outbreak looked like at its most severe point.

Swelling deeper in the skin that may accompany hives is called angioedema. This swelling of the hands and feet, as well as the face (lips or eyelids), can be as dramatic as it is brief.

What causes hives and angioedema? Are hives contagious? Does stress cause hives?

Hives appear when histamine and other compounds are released from cells called mast cells, which are normally found in the skin. Histamine causes fluid to leak from the local blood vessels, leading to swelling in the skin.

Hives are very common and are not considered contagious. Although annoying, hives usually resolve on their own over a period of weeks and are rarely medically serious. Some hives may be caused by an allergic reaction to such things as foods, infections by different organisms, medications, food coloring, preservatives and insect stings or bites, and chemicals; but in the majority of cases, no specific cause is ever found. Although people may find it frustrating not to know what has caused their hives, maneuvers like changing diet, soap, detergent, and makeup are rarely helpful in preventing hives unless there is an excellent temporal relationship. Since hives most often are produced by an immune mechanism, the condition is not contagious. If an infectious disease were the cause of hives in a particular person then it is possible, but not likely, that an infected contact could develop hives.

Having hives may cause stress, but stress by itself does not cause hives.

What are the different kinds of hives?

Hives fall into two categories on the basis of the time they have been present: acute urticaria (ordinary hives, which resolve after six to eight weeks) and chronic idiopathic urticaria (that continues longer than six to eight weeks). Since hives are so common and acute urticaria, by definition, resolves spontaneously, physicians do not generally expend much time or expense to evaluate the cause of hives of less than eight weeks’ duration.

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What are the signs and symptoms of ordinary hives?

Symptoms of ordinary hives flare up suddenly and usually for no specific reason. Welts appear, often in several places. The welts may be skin-colored, pink, or red, and they flare, itch, cause swelling, and go away in a matter of a few minutes to hours, only to appear elsewhere. This sequence may go on from days to weeks. Most episodes of hives last less than six weeks. Although that cutoff point is arbitrary, cases of hives that last more than six weeks are often called chronic hives.

What are the risk factors and causes of ordinary hives?

As noted above, many cases of ordinary hives are «idiopathic,» meaning no cause is known. Others may be triggered by allergic reactions or viral infections. A few may be caused by medications, usually when they have been taken for the first time a few weeks before. (It is less likely for drugs taken continuously for long periods to cause hives but certainly not impossible.) When a medication is implicated as a cause of hives, the drug must be stopped, since testing is rarely available to confirm the cause. In most cases, drug-induced hives will go away in a few days. If a drug is stopped and the hives do not go away, this is a strong indication that the medication was not the cause of the hives.

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Some medications, like morphine, codeine, aspirin, and other nonsteroidal anti-inflammatory drugs (NSAIDs, such as ibuprofen [Advil]), cause the body to release histamine and produce urticaria through nonallergic mechanisms. People with urticaria should avoid these medications.

Despite the reputation of hives being an «allergic» condition, there is often no obvious connection to any provoking substance. In this situation, random allergy testing is not usually helpful. If you know what is causing your hives, then avoiding the cause, if possible.

What are the causes of chronic hives?

Chronic hives (defined as lasting six weeks or more) can last from months to years. The evaluation of this condition is difficult, and allergy testing and other laboratory tests are only occasionally useful in such cases. The accurate evaluation of this condition requires the patient to give his or her physician precise information regarding their complete medical history, personal habits, and oral intake. Occasionally, it may be necessary to limit specific foods or drugs (potential allergens) for a time to observe any affect upon the skin condition. Certain systemic diseases and infections, including parasitic infestations, may occasionally present in the skin as hives. If an inciting cause can be determined, then specific treatments for that condition ought to be effective, or in the case of food allergies or drug allergy, strict avoidance would be necessary. There are additionally rare forms of chronic urticaria that are produced when the patient makes antibodies against molecules on the surface of their own mast cells. There are tests available to identify this type of hives.

Physical urticaria (for example, heat hives) is a type of chronic urticaria produced by physical stimuli. Common environmental provocations such as sunlight (solar urticaria), water, cold, heat, exercise, and pressure occasionally induce hives. Dermatographism, which literally means «skin writing,» is a common cause of physical urticaria. This is an exaggerated form of what happens to anyone when their skin is scratched or rubbed; a red welt appears at the site of the scratch. In dermatographism, raised, itchy red welts with adjacent flares appear wherever the skin is scratched or where belts and other articles of clothing rub against the skin, causing mast cells to leak histamine.

Another common form of physically induced hives is called cholinergic urticaria. This produces hundreds of small, itchy bumps. These occur within 15 minutes of exercise or physical exertion and are usually gone before a doctor can examine them. This form of hives happens more often in young people.

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Are there conditions or other causes that mimic hives?

There are other rashes that may look like hives, but the fact that they remain stable and do not resolve within 24 hours is helpful in distinguishing them from hives. Such rashes may need to have a small specimen of skin removed and examined under the microscope (biopsy) to accurately determine the nature of the skin disease.

When to visit the doctor

If hives are making it difficult to sleep, then it may be necessary to see a physician. This would be especially important if you are taking nonprescription antihistamines. If your hives last longer than two months, it is also likely you will benefit from visiting a physician.

What specialists treat hives?

Some family physicians or internists may feel comfortable caring for patients with chronic urticaria. Most dermatologists and allergists are able to care for patients with urticaria.

How do health care professionals diagnose and evaluate chronic urticaria?

Blood tests, including a complete blood count (CBC) and erythrocyte sedimentation rate (ESR, a marker of inflammation), are all that is typically recommended for evaluation.

SLIDESHOW

What are hives treatment options and home remedies?

How to stop hives

The goal of treating most cases of ordinary acute urticaria is to relieve symptoms while the condition goes away by itself. The most commonly used oral treatments are antihistamines, which help oppose the effects of the histamine leaked by mast cells. The main side effect of antihistamines is drowsiness.

Many antihistamines are available without prescription, such as diphenhydramine (Benadryl), taken in doses of 25 milligrams, and chlorpheniramine (Chlor-Trimeton), taken in a dose of 4 milligrams. These can be taken up to three times a day, but because these medications can cause drowsiness, they are often taken at bedtime. Those who take them should be especially careful and be sure they are fully alert before driving or participating in other activities requiring mental concentration.

Loratadine (Claritin, 10 milligrams) and fexofenadine (Allegra) are antihistamines available over the counter that are less likely to cause drowsiness (non-sedating). Also approved for over-the-counter use is hydroxyzine (Atarax, Vistaril), which causes drowsiness, and its breakdown product, cetirizine (Zyrtec, 10 milligrams), which is less sedating.

Antihistamines that require a prescription include cyproheptadine (Periactin), which tends to cause drowsiness. A prescription antihistamine that causes little sedation is levocetirizine (Xyzal). Sometimes physicians combine these with other types of antihistamines called H2 blockers, such as ranitidine (Zantac) and cimetidine (Tagamet). This antihistamine list is not exhaustive. Physicians individualize treatment plans to suit specific patients and modify them depending on the clinical response.

Oral steroids (prednisone, [Medrol]) can help severe cases of hives in the short term, but their usefulness is limited by the fact that many cases of hives last too long for steroid use to be continued safely. Other treatments have been used for urticaria as well, including montelukast (Singulair), ultraviolet radiation, antifungal antibiotics, agents that suppress the immune system, and tricyclic antidepressants (amitriptyline [Elavil, Endep], nortriptyline [Pamelor, Aventyl], doxepin [Sinequan, Adapin]). Evidence to support the benefit of such treatments is sparse. In ordinary cases, they are rarely needed. A new treatment now indicated for chronic urticaria is the monthly subcutaneous injection of a monoclonal antibody, omalizumab (Xolair), directed against the IgE receptor on human mast cells.

Topical therapies for hives are available but are generally ineffective. They include creams and lotions which help numb nerve endings and reduce itching. Some ingredients which can accomplish this are camphor, menthol, diphenhydramine, and pramoxine. Many of these topical preparations require no prescription. Cortisone-containing creams (steroids), even strong ones requiring a prescription, are not very helpful in controlling the itch of hives.

Applying cool compresses may help soothe the itch of an urticarial rash.

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