As Many Exceptions As Rules

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Exceptions to natural and biological rules are used to increase interest in biology. Recent studies, and not so recent studies, are described in order to demonstrate amazing organisms and practices. Core concepts of biology are emphasized, with side trips into the research of topics that give insight into the evolution and interelatedness of all life.

Mark Lasbury
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  • July 1, 2015
  • 08:30 AM
  • 13 views

Thinking Asymmetrically About Hormones

by Mark Lasbury in As Many Exceptions As Rules

Your endocrine glands are stimulated or suppressed by hormones. They in turn dump hormones into the blood. Blood goes everywhere equally. So why is your left adrenal gland bigger than your right? And why is the size difference larger in domesticated foxes as opposed to wild foxes? For that matter, why is the size of the right lobe of your thyroid gland depend on which hand you use to write!?... Read more »

Trut LN, Prasolova LA, Kharlamova AV, & Plyusnina IZ. (2002) Directional left-sided asymmetry of adrenals in experimentally domesticated animals. Bulletin of experimental biology and medicine, 133(5), 506-9. PMID: 12420075  

Hojaij, F., Vanderlei, F., Plopper, C., Rodrigues, C., Jácomo, A., Cernea, C., Oliveira, L., Marchi, L., & Brandão, L. (2011) Parathyroid gland anatomical distribution and relation to anthropometric and demographic parameters: a cadaveric study. Anatomical Science International, 86(4), 204-212. DOI: 10.1007/s12565-011-0111-0  

  • June 24, 2015
  • 08:00 AM
  • 63 views

The CPU In Your Head

by Mark Lasbury in As Many Exceptions As Rules

It’s hard to believe, but part of your brain – the part that controls your body systems – actually comes from your mouth! What’s more, that same part of the brain talks to cells in your lungs that can smell what you breathe in and may have something to do with Sudden Infant Death Syndrome.... Read more »

Gu, X., Karp, P., Brody, S., Pierce, R., Welsh, M., Holtzman, M., & Ben-Shahar, Y. (2014) Chemosensory Functions for Pulmonary Neuroendocrine Cells. American Journal of Respiratory Cell and Molecular Biology, 50(3), 637-646. DOI: 10.1165/rcmb.2013-0199OC  

  • June 19, 2015
  • 06:30 PM
  • 123 views

Fibonacci Numbers And Odd Lungs

by Mark Lasbury in As Many Exceptions As Rules

Most people think that because they have a pair of lungs, they must be symmetrical – but they’re far from it. The Fibonacci sequence has a lot to do with structural asymmetries in the lungs. On the other hand, some animals have only one lung, some have three lungs, and some have no lungs at all.... Read more »

Wilkinson M, Kok PJ, Ahmed F, & Gower DJ. (2014) Caecilita Wake . Zootaxa, 383-8. PMID: 24871732  

Bickford, D., Iskandar, D., & Barlian, A. (2008) A lungless frog discovered on Borneo. Current Biology, 18(9). DOI: 10.1016/j.cub.2008.03.010  

Goldberger AL, West BJ, Dresselhaus T, & Bhargava V. (1985) Bronchial asymmetry and Fibonacci scaling. Experientia, 41(12), 1537-8. PMID: 4076397  

  • June 10, 2015
  • 08:00 AM
  • 129 views

Everybody Is Just A Little Twisted

by Mark Lasbury in As Many Exceptions As Rules

You may have your head on straight, but your brain is still twisted. Everyone’s is. The symmetry of the brain is not absolute and the two halves are shaped differently, this results in your brain torquing (not twerking) inside your skull. The reasons are many, but one is gender: boy brains and girl brains really are different!... Read more »

Maller, J., Anderson, R., Thomson, R., Rosenfeld, J., Daskalakis, Z., & Fitzgerald, P. (2015) Occipital bending (Yakovlevian torque) in bipolar depression. Psychiatry Research: Neuroimaging, 231(1), 8-14. DOI: 10.1016/j.pscychresns.2014.11.008  

Maller, J., Thomson, R., Rosenfeld, J., Anderson, R., Daskalakis, Z., & Fitzgerald, P. (2014) Occipital bending in depression. Brain, 137(6), 1830-1837. DOI: 10.1093/brain/awu072  

Mock, J., Zadina, J., Corey, D., Cohen, J., Lemen, L., & Foundas, A. (2012) Atypical Brain Torque in Boys With Developmental Stuttering. Developmental Neuropsychology, 37(5), 434-452. DOI: 10.1080/87565641.2012.661816  

Witelson, S., Kigar, D., & Harvey, T. (1999) The exceptional brain of Albert Einstein. The Lancet, 353(9170), 2149-2153. DOI: 10.1016/S0140-6736(98)10327-6  

  • June 3, 2015
  • 08:15 AM
  • 133 views

Left-Handers Have Prettier Brains

by Mark Lasbury in As Many Exceptions As Rules

Take a quick look at the human brain and it seems very symmetrical. Well, it’s not. Which hand you use can help determine just how symmetrical your brain actually is, and for some people that’s really important – they were born with only half a brain!... Read more »

Rogers, L., Zucca, P., & Vallortigara, G. (2004) Advantages of having a lateralized brain. Proceedings of the Royal Society B: Biological Sciences, 271(Suppl_6). DOI: 10.1098/rsbl.2004.0200  

Muckli, L., Naumer, M., & Singer, W. (2009) Bilateral visual field maps in a patient with only one hemisphere. Proceedings of the National Academy of Sciences, 106(31), 13034-13039. DOI: 10.1073/pnas.0809688106  

  • May 27, 2015
  • 08:00 AM
  • 135 views

Hermit Houses And Fiddler Claws

by Mark Lasbury in As Many Exceptions As Rules

Fiddler crabs are an evolutionary marvel. Their major claw is huge, it plays a role in mate selection, but not just in the way you’d think.
Some species are right-clawed and some can have the major claw on either side, but if they lose one and grow it back, the major claw might switch sides! The new major claw isn’t as good for fighting, so he fakes being strong and tries to win without fighting.
... Read more »

Backwell, P., Matsumasa, M., Double, M., Roberts, A., Murai, M., Keogh, J., & Jennions, M. (2007) What are the consequences of being left-clawed in a predominantly right-clawed fiddler crab?. Proceedings of the Royal Society B: Biological Sciences, 274(1626), 2723-2729. DOI: 10.1098/rspb.2007.0666  

  • May 20, 2015
  • 08:00 AM
  • 171 views

The Ugly Butterfly Gets The Girl

by Mark Lasbury in As Many Exceptions As Rules

A current theory is that humans (and other animals) perceive symmetry as beauty and is desirable in a mate. Symmetric bodies and faces are correlated with strength, overall health, facial beauty, and dancing ability, but also with extramarital affairs. On the other hand, on butterfly thrives on ugliness. Asymmetric wings actually help males fly better during sexual competitions and gives them a reproductive advantage.... Read more »

Little, A., Paukner, A., Woodward, R., & Suomi, S. (2012) Facial asymmetry is negatively related to condition in female macaque monkeys. Behavioral Ecology and Sociobiology, 66(9), 1311-1318. DOI: 10.1007/s00265-012-1386-4  

Fink, B., Weege, B., Manning, J., & Trivers, R. (2014) Body symmetry and physical strength in human males. American Journal of Human Biology, 26(5), 697-700. DOI: 10.1002/ajhb.22584  

Thomas F, Doyon J, Elguero E, Dujardin JP, Brodeur J, Roucher C, Robert V, Missé D, Raymond M, & Trape JF. (2015) Plasmodium infections and fluctuating asymmetry among children and teenagers from Senegal. Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases, 97-101. PMID: 25725158  

  • May 13, 2015
  • 08:00 AM
  • 146 views

Half Male, Half Female, Completely Weird

by Mark Lasbury in As Many Exceptions As Rules

It’s tough being a guy. I imagine it’s just as tough being a girl. What if you were exactly half of each? Bilateral gynandromrophs are rare animals that are exactly one half of each sex. They have occurred in insects, crustaceans, spiders, and birds. We know how some come about, but the birds are giving scientists a heck of a time.... Read more »

Renfree, M., Chew, K., & Shaw, G. (2014) Hormone-Independent Pathways of Sexual Differentiation. Sexual Development, 8(5), 327-336. DOI: 10.1159/000358447  

Dumanski, J., Rasi, C., Lonn, M., Davies, H., Ingelsson, M., Giedraitis, V., Lannfelt, L., Magnusson, P., Lindgren, C., Morris, A.... (2014) Smoking is associated with mosaic loss of chromosome Y. Science, 347(6217), 81-83. DOI: 10.1126/science.1262092  

Zhao, D., McBride, D., Nandi, S., McQueen, H., McGrew, M., Hocking, P., Lewis, P., Sang, H., & Clinton, M. (2010) Somatic sex identity is cell autonomous in the chicken. Nature, 464(7286), 237-242. DOI: 10.1038/nature08852  

  • May 6, 2015
  • 08:00 AM
  • 198 views

Plants Aren’t Just Male Or Female

by Mark Lasbury in As Many Exceptions As Rules

It’s hard enough to believe that flowering plants have different sexes, but how about plants that have three sexes? One trioecious plant varies it sex ratio depending on how much water is around, while another only shows three sexes when it lives near a particular bat. But most amazing, man made the papaya into a three-sex plant. Your tropical fruit salad is made with a hermaphrodite.... Read more »

VanBuren R, Zeng F, Chen C, Zhang J, Wai CM, Han J, Aryal R, Gschwend AR, Wang J, Na JK.... (2015) Origin and domestication of papaya Yh chromosome. Genome research, 25(4), 524-33. PMID: 25762551  

  • April 29, 2015
  • 08:00 AM
  • 182 views

The Flower Child Must Be Confused

by Mark Lasbury in As Many Exceptions As Rules

Very few animal species have true hermaphrodites, but over 90% of flowering plants are bisexual. Even though the rest are exceptions, they aren’t all the same type of exception. Some plants are male and some are female all the time, but some change sex every morning they flower. And maple tress can decide to be male or female for a whole year and then change their mind for next year.... Read more »

Spigler, R., & Ashman, T. (2011) Gynodioecy to dioecy: are we there yet?. Annals of Botany, 109(3), 531-543. DOI: 10.1093/aob/mcr170  

Matallana, G., Wendt, T., Araujo, D., & Scarano, F. (2005) High abundance of dioecious plants in a tropical coastal vegetation. American Journal of Botany, 92(9), 1513-1519. DOI: 10.3732/ajb.92.9.1513  

Renner SS, Beenken L, Grimm GW, Kocyan A, & Ricklefs RE. (2007) The evolution of dioecy, heterodichogamy, and labile sex expression in Acer. Evolution; international journal of organic evolution, 61(11), 2701-19. PMID: 17894810  

  • April 22, 2015
  • 08:00 AM
  • 181 views

Boys Will Be Boys… And Then Girls

by Mark Lasbury in As Many Exceptions As Rules

Country teenagers still make summer money detasseling corn, but do you know why it has to be done? This is part of the interesting story of the many breeding systems in plants. Self-pollination is a bad idea, so some plants go to the trouble of switching sexes several times in a week just to avoid it!... Read more »

  • April 15, 2015
  • 08:00 AM
  • 199 views

Boy Plants Are From Mars …..

by Mark Lasbury in As Many Exceptions As Rules

Darwin missed the boat on plants. He recognized sexual dimorphism and sexual selection in animals, but didn’t see the same thing in flowers. Boy plants can look, grow, smell or locate very different from female plants. And it matters – some beetles seek out boy plants for their smell and deliver pollen to girl plants as a bribe for letting them lay eggs there! They have learned to tell guy from gal.
... Read more »

Okamoto, T., Kawakita, A., Goto, R., Svensson, G., & Kato, M. (2013) Active pollination favours sexual dimorphism in floral scent. Proceedings of the Royal Society B: Biological Sciences, 280(1772), 20132280-20132280. DOI: 10.1098/rspb.2013.2280  

  • April 8, 2015
  • 08:00 AM
  • 223 views

Why Do Males And Females Look Different?

by Mark Lasbury in As Many Exceptions As Rules

You see a spotted hyena – is it a male or female. There’s no way of telling without a blood test or a litter of pups. Other animals have obvious differences between males and females; eclectus parrots have green males but red and blue females, while male elephant seals weigh 10x as much as females. Are the differences for sexual selection or natural selection?... Read more »

Cunha, G., Risbridger, G., Wang, H., Place, N., Grumbach, M., Cunha, T., Weldele, M., Conley, A., Barcellos, D., Agarwal, S.... (2014) Development of the external genitalia: Perspectives from the spotted hyena (Crocuta crocuta). Differentiation, 87(1-2), 4-22. DOI: 10.1016/j.diff.2013.12.003  

Hammond, G., Miguel-Queralt, S., Yalcinkaya, T., Underhill, C., Place, N., Glickman, S., Drea, C., Wagner, A., & Siiteri, P. (2012) Phylogenetic Comparisons Implicate Sex Hormone-Binding Globulin in “Masculinization” of the Female Spotted Hyena . Endocrinology, 153(3), 1435-1443. DOI: 10.1210/en.2011-1837  

  • April 1, 2015
  • 08:00 AM
  • 228 views

The Bird Jaws Of Life

by Mark Lasbury in As Many Exceptions As Rules

Do birds have teeth? No, but they did once, and sometimes a throwback mutation can create a chick with a full set of chompers. That’s weird, but bird mouths get weirder. Birds can open their upper jaw, not just their lower. And some birds take being weird even farther. The crossbill has a mouth where the upper and lower beaks scissor past one another while the wrybill has a beak that always turns right. ... Read more »

Meredith, R., Zhang, G., Gilbert, M., Jarvis, E., & Springer, M. (2014) Evidence for a single loss of mineralized teeth in the common avian ancestor. Science, 346(6215), 1254390-1254390. DOI: 10.1126/science.1254390  

Smith, J., Sjoberg, S., Mueller, M., & Benkman, C. (2012) Assortative flocking in crossbills and implications for ecological speciation. Proceedings of the Royal Society B: Biological Sciences, 279(1745), 4223-4229. DOI: 10.1098/rspb.2012.1500  

Benkman, C., Parchman, T., & Mezquida, E. (2010) Patterns of coevolution in the adaptive radiation of crossbills. Annals of the New York Academy of Sciences, 1206(1), 1-16. DOI: 10.1111/j.1749-6632.2010.05702.x  

SNOWBERG, L., & BENKMAN, C. (2009) Mate choice based on a key ecological performance trait. Journal of Evolutionary Biology, 22(4), 762-769. DOI: 10.1111/j.1420-9101.2009.01699.x  

  • March 25, 2015
  • 08:00 AM
  • 274 views

This Nose Knows

by Mark Lasbury in As Many Exceptions As Rules

Evolution has given the sperm whale the most amazing head in the animal kingdom. They’ve got the biggest brain – all 18 lb.s of it. It has 1900 liters of sperm oil that almost caused in the extinction of the animal. It has one nostril that’s offset on its head, making the whale asymmetric. But most impressively, he can change the density of his head to help him dive or surface, and to do it he uses the same organ he uses for echolocation!... Read more »

  • March 18, 2015
  • 08:00 AM
  • 270 views

The Search For The Unicorn - Slightly Off Center

by Mark Lasbury in As Many Exceptions As Rules

One of the most amazing animals is one of the least often seen. It has one tooth that grows into a tusk that’s off center. The tusk is basically inside out, with the inside of the tooth exposed to the world. This animal also has the world’s only spiraled tooth, for strength and because that’s what keeps it growing straight. Finally, this animal spends an amazing amount of time on its back. Why do we care about these animal…..because they are so awesome!... Read more »

Christen AG, & Christen JA. (2011) The unicorn and the narwhal: a tale of the tooth. Journal of the history of dentistry, 59(3), 135-42. PMID: 22372187  

Kingsley, M., & Ramsay, M. (1988) The Spiral in the Tusk of the Narwhal. ARCTIC, 41(3). DOI: 10.14430/arctic1723  

Nweeia, M., Eichmiller, F., Hauschka, P., Donahue, G., Orr, J., Ferguson, S., Watt, C., Mead, J., Potter, C., Dietz, R.... (2014) Sensory ability in the narwhal tooth organ system. The Anatomical Record, 297(4), 599-617. DOI: 10.1002/ar.22886  

Dietz, R., Shapiro, A., Bakhtiari, M., Orr, J., Tyack, P., Richard, P., Eskesen, I., & Marshall, G. (2007) Upside-down swimming behaviour of free-ranging narwhals. BMC Ecology, 7(1), 14. DOI: 10.1186/1472-6785-7-14  

  • March 11, 2015
  • 08:00 AM
  • 241 views

The Eyes Have It

by Mark Lasbury in As Many Exceptions As Rules

The Cyclops had one eye in the middle of his forehead, but can you think of real animal with only one eye? Two eyes (or more) seem to be very important in evolution. This is so true that when flatfish lie down on the ocean floor they move one eye to the other side of their head! Research is showing that it’s more than just their eye that changes and the alterations are important for their survival. And by the way – there is one kind of animal that only has one eye, it’s the &he........ Read more »

  • March 4, 2015
  • 08:00 AM
  • 232 views

Looking Sideways In The Mirror

by Mark Lasbury in As Many Exceptions As Rules

Not every animal that’s bilaterally symmetric chooses to stay that way. Some parasitic worms must become asymmetric in order to attach to fish gills, and some fish have mouths that turn to the right or left for lepidophagy. What’s lepidophagy you ask? They rip off and eat the scales of other fish!... Read more »

  • February 25, 2015
  • 08:00 AM
  • 250 views

Mirroring Evolution

by Mark Lasbury in As Many Exceptions As Rules

Heads and symmetric bodies didn’t necessarily evolve at the same time, but we don’t know which was first. Some animals have heads and bilateral bodies, and some have radial bodies and no heads. Are there any in between? Yes, and no, but why would any group of animals lose heads after they had evolved them?... Read more »

  • February 18, 2015
  • 07:30 AM
  • 330 views

Space - It'll Mess You Up

by Mark Lasbury in As Many Exceptions As Rules

Extended spaceflight can wreak havoc on your body – your bones, muscles, brain and vestibular system all pay the price for exploration. And while your body might adapt to space, big problems can occur when you return to Earth gravity. You go into space as a virile astronaut, but return as fragile as a your great grandmother. ... Read more »

Finetti, F., Paccani, S., Rosenbaum, J., & Baldari, C. (2011) Intraflagellar transport: a new player at the immune synapse. Trends in Immunology, 32(4), 139-145. DOI: 10.1016/j.it.2011.02.001  

Troshichev, O., Gorshkov, E., Shapovalov, S., Sokolovskii, V., Ivanov, V., & Vorobeitchikov, V. (2004) Variations of the gravitational field as a motive power for rhythmics of biochemical processes. Advances in Space Research, 34(7), 1619-1624. DOI: 10.1016/j.asr.2004.02.013  

Fitts, R., Trappe, S., Costill, D., Gallagher, P., Creer, A., Colloton, P., Peters, J., Romatowski, J., Bain, J., & Riley, D. (2010) Prolonged space flight-induced alterations in the structure and function of human skeletal muscle fibres. The Journal of Physiology, 588(18), 3567-3592. DOI: 10.1113/jphysiol.2010.188508  

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