evolution
grrlscientist | January 24, 2008tags: researchblogging.org, neotropical ants, Cephalotes atratus, parasitic nematodes, Myrmeconema neotropicum, tetradonematid nematode, evolution, coevolution, fruit mimicry
A neotropical black ant, Cephalotes atratus,
infected with the newly described parasitic nematode,
Myrmeconema neotropicum.
The ant's infected and swollen abdomen does not actually take on a red pigment.
It becomes a translucent amber. With the yellowish parasite eggs inside and a touch
of sunlight, it appears bright red.
Image: Steve Yanoviak, University of Arkansas.
In the first known example of a parasite…
gregladen | January 24, 2008A hopeful monster is a mutant born with a genetically determined and large novel trait (compared to its parents) which confers enhanced fitness on that individual. This enhanced fitness increases the likelihood that the new mutant gene that determines this trait will be passed on and spread throughout the evolving population, so in a single generation a rapid process of speciation is initiated. For example, a fish with a mutation that causes both its eyes to grow on one side of its head could become the flounder of a new generation of flatfish. Well, just for the halibut, it might be fun…
pharyngula | January 24, 2008We had Neil Shubin here last week, and now Jerry Coyne is guest-blogging at The Loom. I look forward to the day that I can just sit back and invite prominent scientists to do my work for me here.
Although, I have to say that while Coyne is largely correct, he's being a bit unfair. He's addressing Olivia Judson's recent article on "hopeful monsters", a concept Coyne and the majority of the biological community reject. I reject it, too, but I think there are some legitimate issues that are associated with the idea that are also all too often and unfortunately discarded.
One point that Coyne…
loom | January 24, 2008How do new kinds of bodies evolve? It's a question that obsesses many scientists today, as it has for decades. Yesterday, Olivia Judson, an evolutionary biologist and book author, published a blog post entitled "The Monster is Back, and It's Hopeful," in which she declared that these transitions can happen in sudden steps.
Even before I had finished reading Judson's piece, I got an email from the prominent evolutionary biologist Jerry Coyne grousing about it. Coyne, who teaches at the University of Chicago, is an expert on the genetics of adaptation as well as the origin of new species. He…
evolvingthoughts | January 24, 2008
In 1972, David Raup published an influential paper on taxonomic diversity during the Phanerozoic. In that paper, he estimated extinction rates based on the number of fossil families and genera for the period and before and after. The idea was to estimate the "kill rate" of major disruptions in earth's history.
A new paper by Sarda Sahney and Michael J. Benton attempts to do this for the Permian extinction, arguably the biggest of all time. They attempt to reconstruct the "guilds", or ecological roles communities, of the Permian, and assess the biological diversity in terms of taxonomic…
gregladen | January 23, 2008So far no reliable reports seem to be available of a new and potentially interesting, but not necessarily earth-shattering, find in China.
China finds 100,000-year-old human skull: report from PhysOrg.com
An almost complete human skull dating back 80,000 to 100,000 years has been unearthed in central China, state media reported Wednesday.
[...]
grrlscientist | January 23, 2008tags: Speciation in Birds, Trevor Price, book review, evolution, birds
The question of what is a species and how they arise has generated numerous discussions and tremendous controversy throughout the decades. This interest is more than academic, as any bird watcher will tell you since the American Ornithologists' Union (AOU) routinely splits one species into two or lumps two species into one, thereby wreaking havoc with many birders' "life lists"; that master list of species seen that is kept by each birder. More than once, I have heard birders question the validity of one or another of the…
gregladen | January 23, 2008The end-Permian mass extinction event was the big daddy of all the known mass extinction events. Life on the planet Earth was almost entirely wiped out. A new paper explores the post-extinction recovery of ecological systems.
Post extinction dynamics can be understood in relation to several dimensions: Taxonomy (the range and structure of different taxonomic groups); ecology (the interrelationship between the new species and the niches available, as well as the structure and distribution of those niches); and morphology (the overall morphospace filled by the new taxa). The present study…
mikethemadbiologist | January 22, 2008Yesterday, I posted about how feral pigs might be responsible for the spinach-associated E. coli O157:H7 outbreak. A while back, I described the epidemic spread of a new strain of MRSA throughout pigs in Europe. What was puzzling to me was why this MRSA strain, found at forty to sixty-fold greater frequency than all commensal MRSA in humans hadn't entered the human population. A recent paper in Emerging and Infectious Diseases lays out one possible reason--this strain of MRSA does not grow well on retail meat (which is thought to be a major conduit of strains from the farm to humans):
A…
gregladen | January 22, 2008You are going to be hearing a lot more about Darwin in the month of February, which is Darwin Month here on The Internet. (It is also Creationist Home Schooling Science Fair month, so hang on to your mice and keyboards!!!!) I have a Darwin plan of my own that you will be learning of soon enough.
In the mean time, I wanted to remind you of the Beagle Project:
We aim to celebrate Charles Darwin's 200th birthday by building a sailing replica of HMS Beagle and recreating the Voyage of the Beagle with an international crew of researchers, aspiring scientists and science communicators. The…
evolvingthoughts | January 21, 2008
So, I just found out that I'm teaching this semester, which is a comfort (money will come in, and we can eat) and a pain (I am going to Arizona in March, so we will have to sort out some guest lectures or something). The subject is philosophy of the life sciences, but the blurb covers topics I wouldn't have put up myself:
This course looks at some of the philosophical issues arising out of the study of the life sciences-primarily biology & ecology. These issues include problems associated with the theory of evolution such as: (i) recent philosophical debate on the unit of selection; (…
clock | January 21, 2008A paper published back in September - Chimpanzees Share Forbidden Fruit by Hockings et al. is getting renewed attention these days.
Rebecca Walton has compiled links to the recent media and blog coverage of the paper (including those by my SciBlings Afarensis, Greg Laden and Brian Switek), the peer-reviewer's comments have been added to the paper, and The Animal Cognition Research Group at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany has posted a series of comment as part of a Journal Club on this paper.
Now, all you need to do is join in the conversation - log…
gregladen | January 21, 2008Is chimpanzee food sharing an example of food for sex?
One of the most important transitions in human evolution may have been the incorporation of regular food sharing into the day to day ecology of our species or our ancestors. Although this has been recognized as potentially significant for some time, it was probably the Africanist archaeologist Glynn Isaac who impressed on the academic community the importance of the origins of food sharing as a key evolutionary moment. At that time, food sharing among apes was thought to be very rare, outside of mother-infant dyads. Further research…
gregladen | January 20, 2008The Bell Museum, in Minneapolis, will sponsor a Valentine's Day Cafe Scientifique that will be especially close to my heart ...
... mainly because it is me doing it.
Evolution, Cuisine and Romance
Tuesday, February 19, 7 p.m.
Bryant-Lake Bowl, Uptown
Were the opposable thumb, an upright stance and a large brain the most important evolutionary events in human history? According to Anthropologist Greg Laden, these and other traits are only the byproducts of the truly important evolutionary transitions for our species: the rise of romance and the evolution of cuisine. Join Laden for a…
gregladen | January 20, 2008Scientists at The Scripps Research Institute have found that a naturally occurring peptide known for its antibacterial action can also inhibit viral infection.
The study was published in the January 17, 2008 edition of the journal Cell Host & Microbe.
The new study shows that defensins, short antimicrobial peptides that disrupt bacterial membranes and prevent bacterial invasion, use a separate mechanism to ward off adenovirus. Adenovirus is a group of viruses responsible for a number of respiratory diseases as well as infection of the stomach and intestine, eyes, bladder, and skin. While…
gregladen | January 19, 2008Discovery of 'creator' gene for cerebral cortex points to potential stem cell treatments
University of California, Irvine researchers have identified a gene that is specifically responsible for generating the cerebral cortex, a finding that could lead to stem cell therapies to treat brain injuries and diseases such as stroke and Alzheimer's.
Dr. Edwin Monuki, doctoral student Karla Hirokawa and their colleagues in the departments of Pathology & Laboratory Medicine and Developmental & Cell Biology found that a gene called Lhx2 serves as the long-sought cortical "creator" gene that…
jlynch | January 19, 2008
Today sees the formal start of the North Carolina Science Blogging Conference, an event which I unfortunately cannot attend. Instead of spending my Friday with Bora and other science bloggers, I was giving a public talk titled "Evolution Is ..." at Phoenix Country Day School in Paradise Valley. Basic content was to delineate some of the things evolution is (and is not) and to show some of the exciting things we can discover using fossils, molecules, behavioral studies etc. For those that might be interested, I’ve made the slides available here [PDF, 5.85M]
gregladen | January 19, 2008Education committees are beginning to review the science standards for Texas Schools this month. There are indications that efforts will be made to weaken the standing of evolution, or insinuate creationism, creation science, or intelligent design into the standards.
The current Texas Essential Knowledge and Skills standards includes a statement that sudents must learn "the theory of biological evolution." The standards also specify that students must apply critical thinking, address "strengths and weaknesses" in theories.
This does not sound like a bad idea, but it is exactly the kind of…
gregladen | January 19, 2008From the Texas Citizens for Science:
In an email message to its friends, the Institute for Creation Research proposes The Disjunctive Duality of Science Distinction, a new argument to support its effort to obtain Texas Higher Education Coordinating Board approval for its masters degree program in science education. The argument is actually an old one. It posits that two types of science exist, "experimental" science and "forensic, historical, or orgins" science. Only the first is real science, while the second--which, needless to say, includes evolutionary biology--is not a reliable science…