Omne vivum ex ovo

In his book The Blind Watchmaker Richard Dawkins waxes poetic when discussing DNA, genes, and the mutability and movement of both through time. His fifth chapter, The Power of the Archives, includes the following description of seeds falling from a Cotton Wood tree …

It’s raining DNA outside …The cotton wool is mostly made of cellulose, and it dwarfs the tiny capsule that contains the DNA, the genetic information. The DNA content must be a small proportion of the total, so why did I say that is was raining DNA rather than cellulose? The answer is that it is the DNA that matters. Those fluffy specks are, literally, spreading instructions for making themselves. They are there because their ancestors succeeded in doing the same … It is raining instructions out there; it’s raining programs; it’s raining tree-growing, fluff-spreading, algorithms. That is not a metaphor, it is the plain truth. It couldn’t be any plainer if it were raining floppy discs. [I love the  anachronistic reference to floppy discs … the text was first published in 1986.]

I captured the image below on a windy and dry day when several Milkweed seed pods had opened to release their contents. Although I am not enamored with the vernacular concept of the Bucket List, the delicate seed of the Milkweed is a photographic subject that I have had in the recesses of my mind for some time. I must have looked quite the fool to Joanna as I scurried about the pasture inspecting each little bit of fluff as it landed. Several carried what appeared to be aborted seeds. These would not do. Many had landed chaotically and rendered their silky threads in disarray. Some landed on the ground while others floated aloft and into the adjacent wood. The flight trajectory and soft landing of only a very few rendered them appropriate subjects. In our very vertebrate way of thinking it can be easy to assume that all reproductive processes take place somewhere inside. Whether it be spermatogenesis, oogenesis, fertilization, or embryonic development and gestation, events such as these are entirely hidden from view. Vertebrates are rather curious in this regard but remember that they comprise just 3% of the animal kingdom. This proportion is vanishingly small if one includes a variety of other organisms in the calculation. So, vertebrate reproductive processes take place inside. In many other organisms however, including a vast number of both plants, invertebrate animals, and fungi, much of reproduction takes place exclusively outside. In the case of a great number of marine animals, especially those that are either sessile or sedentary, the act of spawning eggs and sperm into the water column is simply a means of achieving fertilization. The liberation of plant pollens into the air or onto an obliging pollinator does the same thing. So the next time you find yourself sneezing because of a nose-full of pollen, enjoying a shower of whirling Maple seeds, or viewing a flotilla of tadpoles cruising the shallows realize that life begets life and it does so in a myriad of fascinating and very different ways. In case you were wondering, the title of this post, Every living thing comes from a living thing (an egg in particular), is one of many phrases which grew out a movement which began with the work of Louis Pasteur who, of course, is known to have disproved the idea of spontaneous generation. The words are those of Francesco Redi who showed that maggots did not arise de novo from decaying meat but rather developed from eggs deposited therein. Click on the image for a view with higher resolution.


POSTSCRIPT: Milkweed belongs to a group of plants which are well known for producing chemicals called cardiac glycosides, a medically important group of drugs which have both therapeutic and toxic effects on the heart. Perhaps you think it strange that a plant should generate such a compound? Did you know that Monarch caterpillars and adult butterflies feed on the milky latex produced by Milkweed and that this material is high in a cardiac glycoside called cardenolide? Cardenolide is noxious and highly toxic to most anything that ventures to ingest it and what we see as beautiful coloration in the Monarch is, in an evolutionary sense, a warning to would-be predators to stay away. What’s even more fascinating is that certain other lepidopterans, such as the Viceroy for example, mimic the Monarch. Ecologists continue to debate whether the Viceroy might be palatable and is avoided by predators because of its resemblance to its noxious partner (this is Batesian Mimicry) or whether the Viceroy is every bit as noxious as its partner and is avoided because of its own display of warning coloration (and this is an example of Müllerian Mimicry).

22 thoughts on “Omne vivum ex ovo

  1. Pingback: If It Only Would Be Edible … | Theory and Practice of Trying to Combine Just Anything

    • Certainly. It is Nikon’s AF-S VR Micro-Nikkor 105mm f/2.8G IF-ED. I spent some time trying to decide between the 60 mm and the 105. Another photoblogger suggested that I go down to a good photo store and put each lens on my camera to see the real difference. Even though both lenses allow a maximum reproduction ratio of 1:1 the 105 allows for a greater working distance. You had to be ‘on top’ of everything with the 60 mm lens. So, the decision was pretty simple after that. I really like the 105 mm and only wish I had more time to play (oops, I mean ‘work’) with it. D

  2. David, this photo is stunning, it’s left me smiling in wonder at nature’s beautiful tiny details. I love the way you caught the flowing milky ‘hair’ of the seed … just beautiful. And as always lots of fascinating science woven around your intriguing photo. Also I find it best not to think about how I look as I’m lying on my belly in the mud, or bending over in a most unladylike fashion … such are the demands of the camera and her art 🙂

  3. I just read your response to Mom’s comment and was wondering how on earth you got such a clear image of something so tiny! The colors and textures are so beautiful! Must have taken you a while to find just the right seed suspended in just the right spot! You clearly have patience which I do not! I could see this blown up and displayed on a gray wall. Very pretty.

    PS: I just finished blowing all the whirly birds from the maple trees off my driveway. This is one seed I do not want to see sprouting this spring!

      • Tell me about it. The Cardinals pitching has been so good, I was skeptical that we could have won in extra innings, but alas, we never got the chance. That play was so damn confusing. Even the players were confused and stunned by it. Gearing up for tonight! If the Sox manage to win this series, I’ll have to get Joanna a commemorative T-shirt!

  4. One of my favorite posts so far… a little biology, a little evolution, a little philosophy and some poetry for good measure…plus a stunning photo. The fibers are so fine, they look like smoke!

    I am actually currently reading a book about how the brain has evolved the capability to read (very meta, I know) and it starts off with a neat reference to the blind watchmaker. The basic premise of the book is the paradox of the fact that the structure and function of human eyes/brains is eerily perfectly suited to reading…but it’s difficult to imagine how all those capabilities evolved independently to allow such a synchronized, complex activity.

    A bit off-topic perhaps, but it’s been making me think about evolution and adaptation a lot lately and your post was a perfect complement to my current state of mind.

    • Absolutely … Dawkins’ The Blind Watchmaker is a really good place to start such a consideration. He talks about coadapted genes and something called linkage disequilibrium – both apply here. He argues that one of the environments within which genes evolve is their immediate genetic environment. Genes share bodies with other genes … and they have to ‘get along’ with these other genes to be selectively advantageous. So .. this is the coevolution part. And as a result of the fact that these complexes work well together, the grouping is selectively advantageous, they tend to move together in evolutionary time … together. He argues that (the genes which are expressed as) herbivore stomachs and herbivore teeth and a number of other herbivore architectures move through time together – because they get along. (the genes which are expressed as) Carnivore stomachs and carnivore teeth and other carnivore architectures similarly move through time together … in the bodies of successful carnivores. So, the same could be same of brain architectures and optic machinery and all of the hardware and software connections that come together as our ability to read. There has been cumulative step selection over millions upon millions of years which has resulted in a phenomenally complex system we call our visual system. Because it is so complex and so seemingly improbable does not mean that selection could not have been responsible for it. They say that, given enough time, the impossible becomes probable. Such wisdom! Let me know what you think of such off-the-cuff analysis. D PS: I have written this in haste … I hope there are not too many typos and mistakes!

  5. This beautiful image will hopefully let me appreciate seeds like that more in the future! I “grow” (or better “let grow”) wild flowers in the garden in a semi-controlled way, among them Fireweed, Chamerion angustifolium (, I needed to google this – “Fireweed” is a much better name than the German equivalent which I didn’t know either before searching for images). Each autumn our office is full of those annoying seeds desperately trying to reproduce 🙂 Though they appear so fluffy and ethereal they stick to all surfaces that are not perfectly plain. This year we cut the plants before the majority of seeds started to float. Probably I should have had a closer look!

    • Yes .. I clicked on the description … “The seed capsule splits from the apex. It bears many minute brown seeds, about 300 to 400 per capsule and 80,000 per plant. The seeds have silky hairs to aid wind dispersal and are very easily spread by the wind, often becoming a weed and a dominant species on disturbed ground.” Sounds like your Fireweed and my Milkweed have converged on a very similar mechanism of seed dispersal! Isn’t evolution wonderful? Thanks for the response and the link Elke. D

  6. That is a gorgeous image. The other day I took photos of the milkweed in our pasture as Char & I walked the line to measure/repair. We’re planning on installing more welded wire and had to get the count for how much to buy, right now it is all electric roping (horse pasture fencing.) Angora Goats are coming my way in November! Interesting article about milkweed. One of my very favorite plants. I’m like a kid when I’m in the fields with them, inspecting for monarch eggs/caterpillars throughout the seasons. Looking for plants with signs of being a host … brings out the September school-child in me. I really enjoyed the quote from Pasteur – I am a word-nerd and Latin was a favorite study of mine in school. Also, though, the Dawkins excerpt makes me want to read his work! Poetic, indeed. When I was moving my son into his new apt. this summer, there were Cottonwoods raining DNA everywhere. He, being a fisherman, informed me about what hatches to be aware of, what the patterns of the fish were, in the season of the Cottonwoods. Apparently there are dams in some reservoirs that have massive “Piles” of fish where the Cottonwood parachutes collect below. Something he would pay attention to when he is fishing a tournament. Beautiful post and photography as always. Hope you are enjoying this late autumn. We had our first frost, here in the Banana Belt of Shaftsbury, last evening. Brought in all of my plants that I wanted to keep, didn’t bother covering the garden because it is pretty empty by now.

    Have a super Wednesday.

    • What a super response Tammy – thanks. I have a couple of friends who are anglers and they too are always going on about the ‘hatch.’ I have never been much of an enthusiast so I usually just nod with appreciation. I am happy to know that there will soon be Angora goats at Wing and a Prayer! We had a Spanish buck once that produced cashmere for us but the stink was a bit off-putting! Our autumn has not been as dramatic as I had been hoping. We’ve had some color but lots of dull weather and sprinkles to go along with it. Few days of the blue sky and puffy white clouds to act as accents to the yellows, oranges, and reds of the foliage. We put the rams out with the ewes just this past Sunday … so we’ll have lambs in the middle of March. Joanna and I are still wanting to make the move back east and we are quite sad about having to part with the flock. [We traveled to New Hampshire a few weeks back to look at a place which turned out to be a real disappointment. Joanna was crushed.] We’ve worked hard for nearly 25 years to get our natural color palette just where we want it – and to now be thinking about giving it up is tough. Hey … you know lots of nice sorts of folks up there in Vermont … you should keep this in the way back of your mind … might you know someone with enough land and enough desire to want really nice fiber flock of Shetlands? Keep the possibility in mind. And might you know of anyone who might know someone who might know someone who knows of opportunities for a not-quite-over-the-hill-yet professor of Biology looking for a bit of a change? Didn’t think it could hurt to ask! D

  7. When I came to the part about your better half watching you scurry about in search of the perfect image (which, by the way, you did find) I was reminded of just a couple of weeks ago when my better half, daughter, and I drove out to Alex and Gertie’s place for the night. On the way along, as we passed the Doe Hills, a fairly high group of hills in the middle of the narrow isthmus that joins the Avalon Penninsula to the rest of the Island of Newfoundland, I just had to stop the car, get out, run to the top of the hills and take a few pictures on what proved to be a beautiful fall evening. She didn’t think much of my scurrying either. I was planning a blog post but couldn’t think of anything suitable to tie them together with. I just popped them up on Imjur if you are interested, by the way. As I read your postscript I chuckled as I realized that’s not far from the real reason why college fraternities all show their colours. Specifically as we know they are as noxious as their brethren and, so, avoid them 🙂 Oh, did I mention that I spent a very pleasant Saturday evening reminiscing at a reunion of my old university residence-mates. It was such fun to discover that even after 35 years we were still basically the same, even if we no longer saw it necessary to ‘show our colours.’ Not sure how noxious we were. Fortunately the inn gave us a private room so we could eat, drink and tell stories without bothering anyone else. Perhaps all women are correct and we men are ‘all alike’ just as they say …

    • ! Wow ! Really nice pictures Maurice. You should surely post them here. Joanna’s reaction as she looked over my shoulder was that the rocks were beautiful and granite (she loves granite and is looking forward to getting out the state of Pennsylvania and leaving behind its sedimentary stones!). She also observed that the rocks you so carefully captured were covered in lush growths of lichen, moss, and lots of other wonderful stuff – the rocks had obviously been there, undisturbed, for a very, very long time. What a beautiful part of the world you live in. Promise you will never, ever, hesitate to stop and photograph it when it presents itself in so lovely a manner! D PS: Your comments about college-age males and fraternity brothers in particular ring a very familiar bell!

  8. Wow and double wow! This picture is amazing! It’s hard to believe you could capture such an image. It is impressive, indeed. The text is for one more scholarly than me, but I appreciate a pretty picture when I see one.

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