Gut bacteria may cause diabetes

13 Friday Apr 2012

Tags

animals, biology, diabetes, Education, Health, Immune response, insulin, microbes, microbiome, Mouse, Popular science, science, TLR2

According to a recent study, your chances of developing adult onset diabetes may depend on what kind of bacteria are living in your gut. It’s been known for some time that type 2 diabetes can be caused by a combination of genetic and lifestyle factors; over the past few years, it’s become clear that these factors somehow interact with the microbiome, but the nature of this interaction and the microbiome’s role in determining susceptibility to diabetes hasn’t been properly explored. Last year a team of scientists from Brazil published results showing that changes in the community composition could completely reverse the effect of genetic factors.
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Natural selection: selfish genes & emergent properties

09 Monday Apr 2012

Posted by sedeer in Evolution, Natural Selection

≈ 8 Comments

Tags

altruism, biology, emergence, emergent properties, Gene, Gene-centered view of evolution, Group selection, macroevolution, Popular science, Richard Dawkins, science, selfish gene, Stephen Jay Gould

I briefly mentioned “gene centred views of evolution” in the final paragraph of my previous post in this series about natural selection. In this post, I’d like to expand a bit on the “selfish gene”, which has proven to be quite a powerful idea, and to present my thoughts on why it nevertheless provides an incomplete view of evolution. I know this can be a controversial subject, so feel free to chime in and start a discussion in the comments.

Earlier posts in this series: Modes of selection, Sexual selection, On fitness.

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Novel approach in plant breeding can recreate parental lines

02 Monday Apr 2012

Posted by sedeer in Genetics, Plants

≈ 5 Comments

Tags

Agriculture, biology, breeding, Chromosome, farming, Heterosis, hybrid, hybrid vigor, Meiosis, Popular science, science, Seed

In a really neat piece of work based around a remarkably simple bit of engineering and some textbook genetics, a team of scientists has found a way to regenerate a plant’s parents through breeding — a technique they call “reverse breeding”. This clever bit of research, which is described in a paper appearing in Nature Genetics, should be applicable to a wide range of crop species, opening up the possibility of significant advances in crop improvement and breeding programmes.

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Excessive hygiene lets the immune system run amok

29 Thursday Mar 2012

Posted by sedeer in Bacteria, Immunology, Microbiology

≈ 8 Comments

Tags

Allergy, animals, Asthma, biology, colitis, Health, Hygiene Hypothesis, Immune system, Mouse, Popular science

Since moving to Finland, I’ve become accustomed to asking guests whether they have any allergies before I prepare dinner. I grew up in the developing world where allergies and asthma seem to be much less common than they are here; in fact, various studies have found higher rates of allergy and autoimmune conditions in developed than developing countries. One explanation for this is the “hygiene hypothesis“, which proposes that excessive hygiene early in life can affect the development of the immune system and result in allergic conditions and autoimmune diseases in later life. In a recent study appearing in Science, a team of scientists in Germany and the United States present evidence supporting the hygiene hypothesis and the importance of an early challenge to the immune system.
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Mammals didn’t have to wait for the dinosaurs to die out

24 Saturday Mar 2012

Posted by sedeer in Dinosaurs, Evolution, Mammals

≈ 1 Comment

Tags

adaptive radiation, animals, Cretaceous–Tertiary extinction event, dinosaur, diversity, mammal, Popular science, teeth

A study recently published in Nature challenges the prevailing wisdom that the extinction of the dinosaurs paved the way for an explosion of mammalian diversity. By studying the fossils of a group of mammals called multituberculates, the researchers have cast doubt on the traditional view of dinosaurs constraining small, shrew-like mammals to a secondary role as nocturnal insectivores. Instead, this group seems to have diversified millions of years before the dinosaurs died out.
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Natural selection: On fitness

20 Tuesday Mar 2012

Posted by sedeer in Evolution, Natural Selection

≈ 6 Comments

Tags

biology, Darwinism, Education, evolution, fitness, natural selection, Popular science, replicator, science, selfish gene, tautology

For the third part in my series about natural selection I’d like to address the concept of fitness. Thanks to the phrase “survival of the fittest”, fitness is quite a prominent idea in the popular perception of evolution. It was originally coined by Herbert Spencer after he read On the Origin of Species; Darwin adopted the phrase in later editions and it’s been popular ever since. Unfortunately, this glib phrase has often eclipsed a more accurate depiction of evolution, leading to some common misunderstandings. This confusion arises because “fitness” has a different meaning in evolutionary biology than it does in general usage. (Have a look at the earlier posts in this series if you haven’t already read them; the first was about the different modes of natural selection and the second discussed selection mechanisms, focusing on sexual selection in particular.)

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