Easter Eggs Un-Shelled

Happy Easter! To everyone who celebrates, I hope you are having a wonderful holiday with friends and family. To all who do not, Happy Sunday and I hope you are getting a ton of candy anyway.

So! Easter is a time of new life, new beginnings and eggs. Eggs eggs eggs. Candied, boiled and plastic. All of the eggs. But! The ones that are hidden and found (fresh now or rotten next year) are amniotic eggs. Anamniotic eggs remain lost and forgotten. Poor things, they represent new life too! Folks discriminate just because they’re a lot harder to paint. If you don’t know why that is, then gather round children and I shall tell you an Easter story.

Once upon a time there was an egg. We know this egg came before a certain tasty bird that everything tastes like because it has no shell. You see, it was an anamniotic egg. First evolved in fish, amphibians and other aquatic life, this egg was adapted for easy disposal of nitrogenous wastes. Denizens of the watery deep and not-so deep excrete ammonia in their waste, which is extremely toxic and needs a lot of water to dilute to safe concentrations. Not a problem for fish, etc. Their soft, jelly-like eggs are semi-permeable, so wastes can diffuse out of the egg into the environment.

Now along came some species that evolved over many generations to be live on land. They are probably reptiles. Since they lay their eggs on land and need more protection from drying in the sun, they have evolved shelled eggs. Like thus:

These are amniotic eggs. The difference between them and anamniotic eggs is not only the presence of a shell, but the presence of an amniotic cavity and defined allantois (waste sac, anamniotes can have this but it’s not as necessary). In fish, etc, the eggs have jelly layers with an analogous function to the amnion, only the composition of each is different. Besides being highly conducive to decoration, the shell is much less permeable. Oxygen and carbon dioxide can diffuse in and out, but not much else. What does that mean for our little egg? It means that they need to pick/evolve to produce a different form of nitrogenous waste. Also they can drown. But evolve they did, thank heavens. So now egg-laying (oviparous) vertebrates like reptiles and birds excrete non-toxic uric acid. This requires little water to dilute and may be stored in the allantois until the chick/baby turtle/snakelet hatches.

And all the little eggies lived happily ever after. The end.

Post Script: Once upon a different time, I was forced to watch Megashark vs. Crocasaurus by a certain someone who-shall-not-be-named (Ian, it was Ian). At one point Crocasaurus lays a ton of eggs off some nondescript coast and everyone is panicking because they somehow know she’s laid eggs (parthenogenic croc, I guess?) but not where. I could not get over it; “Why are they panicking, the eggs are dead. They drowned. This is why there are no other crocasauri.”

Source

Campbell, Niel A. “Nitrogenous Wastes.” Excretory System. 2^nd Ed. University of California, Riverside. March 31, 2013. <http://ex-anatomy.org/nitro.html>

Egg photo credit: Nicole. 2012. “Ready For Easter.” <http://daisyodd.deviantart.com/art/Ready-for-Easter-290000381?q=gallery%3Adaisyodd%2F5286180&qo=2&gt;

Stalling at Morning Glory Pool

Sorry to miss another post this week, but my brother has just gotten engaged and we’re all in an absolute tizzy! Tizzy, I say! Which means a lot of bridal magazines and pizza.

Speaking of which…

 

EDIT: This is Morning Glory Pool in Yellowstone National Park. Picture credit to me.

Mitosis Hand Jive

I would like to introduce you all to the Mitosis Hand Jive, it was a thing born out of high school biology class and has served me well in the years since. I cannot claim credit for the Mitosis Hand Jive, credit goes to my good friend who shall be known only as…Tay Tay.

What is the Mitosis Hand Jive, you ask? First off, it is a hand jive. Second, it involves mitosis, or cell division in eukaryotes (non-bacteria, basically). Seriously though, it’s a mnemonic I’ve used to help remember the basic steps of mitosis. So, be you in a park, office, coffee house or armadillo farm, I invite you to follow along. Imagine some chipper, appropriately tempo-ed music playing.

Prophase: Within the nucleus, DNA condenses from loose chromatin (less organized DNA) into compact, finger-like chromosomes. Prior to mitosis, the DNA replicated so the chromosome number is double and the new copies are paired with the originals. Meanwhile, the nuclear envelope dissolves and two structures called centrosomes are getting into position…

Metaphase: Once the nuclear envelope has dissolved, the centrosomes can grab the paired chromosomes by the centromere (point where the pair is bonded) and drag them to the middle of the cell.

Anaphase: With a mighty yank, the centrosomes pull the paired chromosomes apart and to opposite ends of the cell. Because the spindles attached at the centromere, no bits are left behind (though mistakes can happen, no one’s perfect, after all).

Telophase: Although the cell has not divided yet, two nuclear envelopes are forming around the separated chromosomes.

Cytokinesis: Separate nuclei now fully formed (with the correct number of chromosomes), a cleavage furrow (that is what it’s called, visualize it how you will) develops as the two cells pinch off and separate.

Bam! Now you know the Mitosis Hand Jive. It helps the most in understanding what the chromosomes are doing since your fingers directly represent those. But once you get that down, the rest comes along easier. Also, if you do it twice, you have the Meiosis Hand Jive. Only problem is that for meiosis (cell division of sex cells, like the precursors to sperm and eggs), the chromosome number starts out as doubled (2N) and ends halved (.5N) from normal cells. Kind of hard to incorporate that into a hand jive without also incorporating knives and impromptu surgery.

Don’t cut your hands for studying, it’s not worth it and you need those to take tests.

 

Source

-. 2010. GRE Subject Test: Biology 5th Ed. Kaplan, New York.

Mom for the photography and myself for the modeling.

Tay Tay.

Sea Penning an Apology

I’ve come down with a bug and I’m not feeling too well (see: John Mayer was Wrong). I’ve got something fun planned for tomorrow, but until then, here’s a sea pen to keep y’all entertained. Sea pens are cnidarians and colonial (one “pen” is made up of many individuals, here called polyps) relatives to jellyfish and anemones. They are benthic (sea-floor dwellers) but can detach and swim away if threatened. Also they bioluminesce when poked (see: A Glowing Review of Bioluminescence).

Okay, time now for me to settle in with some hot curry and a blanket. Probably a lot of tissues, too.

Homos and Anas

Because I can only be SO relevant to current events, today I am addressing homo…ology. Homology literally means “similar structures”, but in biology we differentiate between “serial” homology and “structural” homology. Both of these are very distinct from analogy.

First! Serial homology, for which snakes are an excellent example. Think of their ribs, you only have…uh, a limited number, but snakes have a lot more. Like the reticulated python above. Beautiful girl, 14 years old and 18 feet long (old enough and yet way too big for middle school. Poor thing will never get to prom), can you imagine the ribs she has? The many, many vertebrae and ribs of this python serve the same purpose in the same species and look…THE SAME. This is serial homology; those rib-vertebrae structures are in a series in the python and display homology.

Now, structural homology may require a slightly different image. Firstly, look at your hand, now look at the wings of this pooping Rodriguez Fruit Bat.

The bones in a bat wing are like elongate versions of your fingers. Just with some skin stretched between so that they can fly. Here, the structures are homologous, even if the function is not.

Finally, we have analogues. In biology, analogous structures have a similar function, but very different structures. Look at your hand, now look at this chicken.

NOW BACK TO YOUR HAND. Here are the fingers in the hand you love. THE FINGERS HAVE BECOME A BAT WING. By comparison the chicken wing is formed largely from only a couple fingers in the “hand” template, unlike the bat wing which uses all fingers. I’m on a horse. Anything is possible when you have functional structures with great flexibility in regards to adaptive variation.

Batting My Eyelashes/Stalling

Eyelash Viper while I try to come up with a good topic for today.

Gifts of the Spices and Seasonings Part 2

After yesterday’s post, I’m sure you’re all wondering HOW your curry is antimicrobial. If not, then I’m not doing my job right! Or you’re not eating enough curry. Anyway, the true heroes of microbial inhibition are sulfur dioxide and phenols. For those of you unaware, a sulfur dioxide molecule contains one atom of sulfur bonded to two oxygen atoms (hence the “dioxide” bit). In your bloodstream after a nice garlic-and-onion-filled meal, it relaxes the blood vessel walls and thereby reduces blood pressure while giving you the kind of breath that would scare buzzards. Great stuff, right? Bacteria would not agree. While some bacteria LOVE sulfur, those involved in food spoilage do not. Sulfur dioxide gets all up in bacterial protein business, completely messing up their shit by binding to components of oxidation. Enzymes are particularly affected and their reduced function is lethal for the bacteria.

Phenols on the other hand don’t roll that way. Carbon rings with an alcohol group and other various bells and whistles, “phenol” is a very broad chemical term. However, when you’re thinking of antimicrobial components of spices, you’re thinking of eugenol, thymol and carvacrol. Found in cinnamon, cloves, sage and oregano, these phenols are badass. Quite simply, they destroy cell membranes. Doesn’t matter where, doesn’t matter what, fungi, bacteria, in a box with a fox, whatever. They’ll take it down.

So next time your coworkers commence sniffling and sneezing, grab what cold remedy you will, but to really battle the bugs, just spice things up a little.

 

Oh, and since I don’t have any fun, pertinent pictures today, here’s a sea otter washing his face.

 

 

Source

-. 2009. Winemaking. Practical Winery and Vineyard Journal. March 26, 2013.

-. 2010. GRE Subject Test: Biology 5th Ed. Kaplan, New York.

Billing, J and PW Sherman. 1998. Antimicrobial functions of spices: why some like it hot. Quarterly Review of Biology 73(1):3-49.

Oyedomi, SO, AI Okoh, LV Mabinya, G Pirochenva and AJ Afolayan. 2009. The proposed mechanism of the bactericidal action of eugenol, terpineol and terpinene against Listeria monocytogenes, Streptococcus pyogenes, Proteus vulgaris and Escherichia coli. African Journal of Biotechnology 8 (7): 1280-1286.

Sherwood, Lauralee, Hillar Klandorf and Paul Yancey. 2005. Animal Physiology: From Genes to Organisms. Thomson Brookes/Cole, Belmont, CA.

Photo courtesy of me, otter courtesy of the Seattle Aquarium

Gifts of the Spices and Seasonings

Sadly, this is not a post about bacon, or bacon-flavored ice cream, for that matter. However bacon is a good segue into the science I AM going to toss your way and that is antimicrobials. Why do you think such a salty, blood-pressure destroying thing was invented (without knowing how delicious it would be)? Salt-cured meats are HIGHLY resistant to spoilage via microbes and fungi. The salty environment sucks moisture from microbial and fungal cells, making them so hypertonic (thirsty and shriveled) they die.

Yet salt is not the only antimicrobial seasoning out there. In hot, tropical climates, a lot of salty food is a very bad idea unless you enjoy severe dehydration. Instead, hot, tropical cooks employ various spices containing compounds that naturally reduce spoilage by inhibiting the growth of bacteria, yeasts and mold. Now for some anthropology/microbiology crossover action: a study examining the use of 43 different spices in meat-based dishes from 36 different studies found that the higher the average annual temperature, the more spices were used in individual recipes. In addition, recipes of total studied used more spices and the more of the most potently antimicrobial spices (Billing and Sherman, 1998). But wait! There’s more…Not only can spices keep your food germ-free, but they keep you healthy too. Cinnamon alone helps with cholesterol and bloodsugar management, while garlic and onion (a vegetable, but often used as a seasoning) are excellent for lowering blood pressure and warding off vampires.

More microbe mauling spices include allspice, clove, oregano and various peppers. As well as sage, rosemary and thyme. Haven’t found anything scientific supporting parsley though.

Tomorrow I plan on exploring the compounds that help these spices work these wonders. But right now it’s sunny in Seattle and I need to enjoy this while it lasts.

 

Sources

Billing, J and PW Sherman. 1998. Antimicrobial functions of spices: why some like it hot. Quarterly Review of Biology 73(1):3-49.

Snyder, P. 1997. Antimicrobial Effects of Spices and herbs. Retrieved March 25, 2013, from Hospitality Institute of Technology and Management, St.Paul, Minnesota Website: http://www.hi-tm.com/Documents/Spices.html.

 

Bonus points if you got the song I attempted to reference.

WTF Evolution- Devil’s Tooth Fungus

WTF Evolution- Devil’s Tooth Fungus

There are prettier, more shapely, more useful and tastier fungi out there, but Devil’s Tooth is my favorite.

Just thought I’d share that with you guys.

Scared Sticky

Some animals have armor, others are poisonous, still others put on light shows or hide to avoid predation. Then there are those…who just turn into a hot mess.

Slime Star

The slime star is probably the most exciting starfish you will meet.

GUESS HOW IT GOT ITS NAME. GUESS.