Life Sciences
tetrapodzoology | July 1, 2008
Distractions distractions distractions. Mayfly chameleons. Sea monster carcasses. Avian supertrees. Fake tiger photos. New pterosaurs. Frogs. But... must... complete... borhyaenoid... articles... For the intro, go here. Time now to crack on with hathlyacynids and prothylacinids. If you don't care, let me note that this is (to my knowledge) the biggest amount of information yet made available on these animals outside of the technical literature. Yes yes, I feel your love, thank you...
Hathlyacynidae is the biggest and longest-lived borhyaenoid clade, with members that range in age from Late…
edyong | July 1, 2008The mayfly is known for its incredibly short adult life. After spending months as larvae, the adults finally hatches only to fly, mate and die within the space of a day. Now, in the dry south-west corner of Madagascar, scientists have discovered the lizard equivalent of the mayfly - Labord's chameleon (Furcifer Labordi).
The lifespan of Labord's chameleon is hardly as compressed as that of a mayfly, but it is extraordinarily short for a tetrapod (an animal with four legs and a backbone). From laying of egg to kicking of bucket, the lizard's entire life is played out in a year and 7 months…
clock | June 30, 2008Mammalian Clock Protein Responds Directly To Light:
We all know that light effects the growth and development of plants, but what effect does light have on humans and animals? A new paper by Nathalie Hoang et al., published in PLoS Biology, explores this question by examining cryptochromes in flies, mice, and humans. In plants, cryptochromes are photoreceptor proteins which absorb and process blue light for functions such as growth, seedling development, and leaf and stem expansion. Cryptochromes are present in humans and animals as well and have been proven to regulate the mechanisms of the…
grrlscientist | June 30, 2008tags: smuggling parrots, poaching parrots, ProFauna Indonesia, endangered species, conservation, politics
Indonesians protest the illegal wildlife trade.
Image: ProFauna Indonesia.
You know that I am passionate about the parrots of the south Pacific Ocean -- I devoted my life to researching them, in fact. So it is my responsibility to bring a very important and tragic issue to your attention. Indonesia, home to many of the birds that I love so much, is killing its endemic parrots through poaching and smuggling.
There are 85 parrot species in Indonesia, 14 of which are globally threatened…
grrlscientist | June 30, 2008tags: Birds in the News, BirdNews, ornithology, birds, avian, newsletter
Ruby-crowned Kinglet, Regulus calendula, with insect egg or pupa in its beak.
Image: Dave Rintoul, KSU [larger view].
News of Birds in Science
A fascinating paper was just published by some of my colleagues in the top-tier journal, Science, that analyzes the largest collection of DNA data ever assembled for birds. This analysis effectively redraws avian phylogeny, or family tree, thus shaking up our current understanding of the early, or "deep", evolutionary relationships of birds. For example, one of the most…
tetrapodzoology | June 29, 2008
By now I hope it's clear, even to novices with no special interest in the extinct wildlife of the Cenozoic, that ancient South America had what we might technically call a Really Awesome Faunal Assemblage. Astrapotheres, sebecosuchians, phorusrhacids, teratorns, gigantic caimans, madtsoiid snakes, sloths, glyptodonts... and this is only half of it, there's so much more. It occurred to me a while back that it would be only fair and proper to cover yet another of South America's extinct Cenozoic groups, and yet again it's a bunch of animals on which comparatively little information is freely…
grrlscientist | June 29, 2008tags: Return To Warden's Grove, ornithology, birds, field research, biology dissertation, Christopher Norment, book review
Throughout my life, certain people have had the audacity to lecture me about how a scientific education and a scientific life forever destroys a person's ability to appreciate nature. I always tell them how science enhances my appreciation and .. dare I say it? .. my love of the natural world, but I sometimes think no one hears me. But thanks to the wonderful book, Return To Warden's Grove: Science, Desire, and the Lives of Sparrows by Chris Norment (Iowa City: University…
pharyngula | June 27, 2008
The paleontologists are going too far. This is getting ridiculous. They keep digging up these collections of bones that illuminate tetrapod origins, and they keep making finer and finer distinctions. On one earlier side we have a bunch of tetrapod-like fish — Tiktaalik and Panderichthys, for instance — and on the later side we have fish-like tetrapods, such as Acanthostega and Ichthyostega. Now they're talking about shades of fishiness or tetrapodiness within those groups! You'd almost think they were documenting a pattern of gradual evolutionary change.
The latest addition is a description…
edyong | June 27, 2008For humans, sight is the most important of senses but only after we are born. Within the womb, surrounded by fluid, muscle and darkness, vision is of limited use and our eyes remain closed. But not all animals are similarly kept in the dark.
Cuttlefish develop inside eggs that are initially stained black with ink, but as the embryo grows and the egg swells, the outer layer slowly becomes transparent. By this time, the developing cuttlefish's eyes are fully formed and we now know that even before they are born, they can use visual information from the outside world to shape their adult…
gregladen | June 26, 2008... is certainly still in the future. But we have seen a step in that direction in a new paper, coming out this week in Science. This research applies intensive and extensive genomic analysis to the avian phylogenetic tree. The results are interesting.
This paper is summarized in a number of locations, most notably here on Living the Scientific Life. Here, I will summarize it only very briefly. However, there are two observations I would like to make about this paper and its apparent meaning. One has to do with the nature of science, and the other has to do with the nature of…
grrlscientist | June 26, 2008tags: researchblogging.org, Early Bird Project, Tree of Life, avian evolution, deep avian evolutionary relationships, avian phylogenomics, location cues, Shannon J. Hackett, Rebecca T. Kimball, Sushma Reddy
Basic topology of the evolutionary relationships between birds.
Maximum Likelihood (ML) phylogram reveals the short internodes at the base of Neoaves and highlights certain extreme examples of rate variation across avian lineages. The phylogenetic tree was rooted to crocodilian outgroups (not shown). Branch colors represent major clades supported in this study: land birds (green),…
pharyngula | June 26, 2008
This is an amphioxus, a cephalochordate or lancelet. It's been stained to increase contrast; in life, they are pale, almost transparent.
It looks rather fish-like, or rather, much like a larval fish, with it's repeated blocks of muscle arranged along a stream-lined form, and a notochord, or elastic rod that forms a central axis for efficient lateral motion of the tail…and it has a true tail that extends beyond the anus. Look closely at the front end, though: this is no vertebrate.
It's not much of a head. The notochord extends all the way to the front of the animal (in us vertebrates, it…
kevin z | June 25, 2008That is the common theme in marine biology. Clara Moskowitz has an article up at LiveScience describing how scientists are struggling to keep up with marine life discoveries. Here is a short snippet:
"Scientists figure there are at least 1 million species of marine organisms on Earth.
Of these, only about 230,000 are known to science now, and some of those have more than one name. To keep them all straight, 55 researchers from 17 countries are working on a new list, the ultimate tally of sea creatures great and small.
The list is about half done, the team announced today. So far, the…
scientificactivist | June 24, 2008On Monday, the Supreme Court agreed to hear Winter v. Natural Resources Defense Council, a case regarding the Navy conducting sonar training exercises in the proximity of marine mammals--some of which are threatened or endangered species. A large body of evidence indicates that these sorts of sonar exercises--which generate extremely loud underwater sounds--damage the hearing of these animals and disrupt their behavior, often leading to beached whales. And, at their worst, these exercises have been linked to scores of whale deaths--likely from decompression sickness as the whales panicked…
laelaps | June 24, 2008In an essay called "The Reception of the 'Origin of Species'" printed in Life and Letters of Charles Darwin (and reprinted in Life and Letters of Thomas Henry Huxley), "Darwin's Bulldog" T.H. Huxley described the intellectual shock of understanding Darwin's theory of evolution by natural selection;
As I have already said, I imagine that most of those of my contemporaries who thought seriously about the matter, were very much in my own state of mind -- inclined to say to both Mosaists and Evolutionists, "a plague on both your houses!" and disposed to turn aside from an interminable and…
gregladen | June 23, 2008Continuing with our discussion of the Evolution 2008 conference ...
Karen Oberhauser talked about the "single species" approach to pedagogy. This involves focusing on a single species and using it throughout an entire course. Karen has taught classes on this approach for teachers' professional development programs.
The species she uses is the Monarch Butterfly.
Karen is a world class expert on this insect, and runs a major research project with them.
The idea of a single-species approach is that a student learns a great deal about one particular species, to the extent that this…
edyong | June 23, 2008In 2004, the Australian Government turned a third of the Great Barrier Reef into the largest network of no-fishing zones in the world. All fishing was banned in an area of sea just smaller than England. It was a bold and controversial political move - jobs and livelihoods, it was said, were on the line. But the plan went ahead and in just a few years, there are signs that it's working. One of the reef's most heavily fished species - the coral trout- is enjoying a dramatic comeback, thanks to this most ambitious of marine conservation projects.
The vast expanse of the Great Barrier Reef is…
jrosenhouse | June 21, 2008I have spent the last few days working my way through Ken Miller's new book Only a Theory: Evolution and the Battle for America's Soul. (OAT) Short review: Worth reading, but also a bit disappointing. Now for the long review:
My first published piece of writing on evolution was a review of Miller's book Finding Darwin's God, (FDG) for Skeptic magazine. My reaction to the book was probably typical among atheists. The first half of the book is a masterful smackdown of creationism and intelligent design. Miller's arguments were clear and convincing, and written in graceful prose that was a…
clock | June 19, 2008Great Apes Think Ahead: Conclusive Evidence Of Advanced Planning Capacities:
Apes can plan for their future needs just as we humans can - by using self-control and imagining future events. Mathias and Helena Osvath's research, from Lunds University Cognitive Science in Sweden, is the first to provide conclusive evidence of advanced planning capacities in non-human species.
Female Chimps Use Copulation Calls Strategically:
Female chimps are more concerned with having sex with many different males than finding the strongest mate, according to researchers. The new study by University of St…
tetrapodzoology | June 18, 2008
As if the revelations about Brontornis and all that new work on the ameghinornithids weren't enough, 2007 also saw the publication of a long-awaited new study on the age of Titanis walleri, North America's only phorusrhacid, and - supposedly - a species that survived until as recently as 15,000 years ago. Yes, it's time to crack on with more terror birds, or phorusrhacids. It's a story of ancient island-hopping, of the proposed re-evolution of clawed forelimbs, and of Raven, the giant claw-handed bird of Native American folklore...
Titanis walleri Brodkorb, 1963 is one of the largest and…