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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  • May 27, 2015
  • 08:00 AM
  • 40 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
  • 71 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
  • 81 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
  • 120 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
  • 124 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
  • 126 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
  • 141 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
  • 171 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
  • 175 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
  • 228 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
  • 231 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
  • 206 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
  • 194 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
  • 222 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
  • 283 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  

  • February 11, 2015
  • 08:00 AM
  • 279 views

Thinking Skinny Thoughts Won’t Help

by Mark Lasbury in As Many Exceptions As Rules

As with so many other things, we learn biology best by studying what happens when things go wrong. You won’t believe the diseases that are being linked to this most innocuous of cell structures. Without any exaggeration, primary cilia make you smart, skinny, and happy. Let’s find out how.... Read more »

Tong, C., Han, Y., Shah, J., Obernier, K., Guinto, C., & Alvarez-Buylla, A. (2014) Primary cilia are required in a unique subpopulation of neural progenitors. Proceedings of the National Academy of Sciences, 111(34), 12438-12443. DOI: 10.1073/pnas.1321425111  

Han, Y., Kang, G., Byun, K., Ko, H., Kim, J., Shin, M., Kim, H., Gil, S., Yu, J., Lee, B.... (2014) Leptin-promoted cilia assembly is critical for normal energy balance. Journal of Clinical Investigation, 124(5), 2193-2197. DOI: 10.1172/JCI69395  

Davenport JR, Watts AJ, Roper VC, Croyle MJ, van Groen T, Wyss JM, Nagy TR, Kesterson RA, & Yoder BK. (2007) Disruption of intraflagellar transport in adult mice leads to obesity and slow-onset cystic kidney disease. Current biology : CB, 17(18), 1586-94. PMID: 17825558  

Keryer, G., Pineda, J., Liot, G., Kim, J., Dietrich, P., Benstaali, C., Smith, K., Cordelières, F., Spassky, N., Ferrante, R.... (2011) Ciliogenesis is regulated by a huntingtin-HAP1-PCM1 pathway and is altered in Huntington disease. Journal of Clinical Investigation, 121(11), 4372-4382. DOI: 10.1172/JCI57552  

Miyoshi, K., Kasahara, K., Miyazaki, I., & Asanuma, M. (2009) Lithium treatment elongates primary cilia in the mouse brain and in cultured cells. Biochemical and Biophysical Research Communications, 388(4), 757-762. DOI: 10.1016/j.bbrc.2009.08.099  

  • February 4, 2015
  • 08:00 AM
  • 261 views

An Immovable Moving Part- That’s Just Cilia!

by Mark Lasbury in As Many Exceptions As Rules

Nothing is simple, and we wouldn’t want it that way. The cilia on cells; they’re for propelling a cell forward or back, or for moving fluid past the cell. Unless they don’t move at all. Could a broken cilium be important to us? You bet, they control every part of our lives. And some aren’t even cilia; sterocilia are made completely differently, but the diseases of cilia affect sterocilia as well – they can make you blind, deaf and unbalanced.... Read more »

  • January 28, 2015
  • 08:00 AM
  • 313 views

Crawling To The Top

by Mark Lasbury in As Many Exceptions As Rules

Nematodes cause horrible diseases, but they way they reproduce is the most fascinating thing about them. Their sperm aren’t shaped like typical animal male gametes. They crawl instead of swimming, and they have a type of cytoskeleton not seen in any other cell type on Earth. Yet, the nematode is the most numerous type of animal on Earth.... Read more »

Smith HE. (2014) Nematode sperm motility. WormBook : the online review of C. elegans biology, 1-15. PMID: 24715710  

H. Ferris. (2009) The beer mat nematode, Panagrellus The beer mat nematode, Panagrellus redivivus: A study of the connectedness of scientific discovery . J. Nematode Morphol. Syst., 12(1), 19-25. info:/

McKnight, K., Hoang, H., Prasain, J., Brown, N., Vibbert, J., Hollister, K., Moore, R., Ragains, J., Reese, J., & Miller, M. (2014) Neurosensory Perception of Environmental Cues Modulates Sperm Motility Critical for Fertilization. Science, 344(6185), 754-757. DOI: 10.1126/science.1250598  

  • January 21, 2015
  • 07:45 AM
  • 252 views

Evolving A Second Job

by Mark Lasbury in As Many Exceptions As Rules

Centrioles are the most amazing structures in your cell. They don’t have DNA, yet they duplicate to form more of themselves or they can form spontaneously if lost. They control the beating direction of the cell’s cilia; change one’s direction and all of the cells for hundreds of generations will remain moving in the wrong direction.... Read more »

Henderson, B., & Martin, A. (2014) Protein moonlighting: a new factor in biology and medicine. Biochemical Society Transactions, 42(6), 1671-1678. DOI: 10.1042/BST20140273  

Kobayashi, T., & Dynlacht, B. (2011) Regulating the transition from centriole to basal body. The Journal of Cell Biology, 193(3), 435-444. DOI: 10.1083/jcb.201101005  

Debec, A., Sullivan, W., & Bettencourt-Dias, M. (2010) Centrioles: active players or passengers during mitosis?. Cellular and Molecular Life Sciences, 67(13), 2173-2194. DOI: 10.1007/s00018-010-0323-9  

Boisvieux-Ulrich E, & Sandoz D. (1991) Determination of ciliary polarity precedes differentiation in the epithelial cells of quail oviduct. Biology of the cell / under the auspices of the European Cell Biology Organization, 72(1-2), 3-14. PMID: 1756309  

  • January 14, 2015
  • 08:00 AM
  • 312 views

Everybody In The Gene Pool - Plants That Swim

by Mark Lasbury in As Many Exceptions As Rules

Plants can be moved by wind and water. Their pollen and seeds can be moved by insects, wind, gravity, but plants themselves don't have motile cells. Well – that’s not always true. Some trees have swimming cells; they take the plunge in order to find a mate.... Read more »

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