evolution
evolgen | February 6, 2007Where the variation comes from.
Evolution proceeds by the action of many different evolutionary forces on heritable variation. Natural selection leads to the increase in frequency of variation that allows individuals to produce more offspring who, themselves, produce offspring. Genetic drift changes the frequency of variation through random sampling of individuals from one generation to the next. Population subdivision divides the variation into isolated groups where other forces (selection, drift, etc) act upon it. But where does all this variation come from?
Given the title of the post, the…
clock | February 6, 2007For Some Species, An Upside To Inbreeding:
Although breeding between close kin is thought to be generally unfavorable from an evolutionary standpoint, in part because harmful mutations are more easily propagated through populations in this way, theory predicts that under some circumstances, the benefits of inbreeding may outweigh the costs.
Researchers have now reported real-life evidence in support of this theory. Studying an African chiclid fish species, Pelvicachromis taetiatus, in which both parents participate in brood care, the researchers found that individuals preferred mating with…
clock | February 5, 2007Just quickly for now without commentary:
Totally cool paper in the last Science:
S. Libert, J. Zwiener, X. Chu, W. VanVoorhies, G. Roman, and S.D.Pletcher
Regulation of Drosophila lifespan by olfaction and food-derived odors:
Smell is an ancient sensory system present in organisms from bacteria to humans. In the nematode Caeonorhabditis elegans, gustatory and olfactory neurons regulate aging and longevity. Using the fruit fly, Drosophila melanogaster, we show that exposure to nutrient-derived odorants can modulate lifespan and partially reverse the longevity-extending effects of dietary…
evolvingthoughts | February 4, 2007
The Biohumanities Project of Paul Griffiths, of which I am a minor part, has a page up of talks and discussions at conferences and workshops, recorded for podcasting. We have just revamped and shifted our podcast page to here. If you want to stay abreast of these, subscribe to our RSS feed.
Some of the crispy goodness: A conference on mechanism and reduction, a conference on the philosophy of ecology, and a conference on evidence based medicine, plus talks on emotion, essentialism and biological hierarchies.
evolvingthoughts | February 3, 2007
Some time back I added a little piece of conceptual mapping to the Talk.Origins Archive entitled "So you want to be an anti-Darwinian?" Now Laurent Penet has (I trust faithfully - my French is non-existent, as I found out in Paris) turned it into a French essay, along with Mark Isaak's Bombadier Beetle essay (English version here). It's amazing how much more important my own words look in French. Thanks to Laurent - now I can die happy, having been translated into at least one language other than English (and believe me, translating the contents of my head into English is no small task).
pharyngula | February 3, 2007Reader Ted sent along a rebuttal to that pathetic evolution "simulation" written by a creationist—it's a much better simulation that was presented at TAM5, called IC Evolver. The simulation plays a simple game that has a strategy that can be encoded in strings, and it starts with a set of randomized strategies, which it then uses and modifies, generation after generation, to maximize the score. Two cool things about it: one is that it modifies the strategy with common genetic operations, like insertions, deletions, point mutations, and recombination, and displays them graphically so you can…
evolvingthoughts | February 2, 2007
Rob Skipper has a relatively accessible post on what Fisher and others think the Fundamental Theorem of Natural Selection means. The old joke has it that it's neither fundamental nor a theorem, but Rob goes into more detail based on a seminar he and his students did.
One thing - "genic variance" is undefined. As I understand it, that is the amount of phenotypic variation in a population that is due to genetic differences between individuals. Thats the definition I could find, anyway.
clock | February 2, 2007A few weeks ago I mentioned (and kinda joked about it - see the accompanying images) a study about the adaptive function of the giraffe's neck. Now Darren Naish goes into more detail about the study and does it much more seriously than I did. And John Wilkins adds a historical context (to which I alluded in my older post).
evolvingthoughts | February 2, 2007
Darren Naish has a typically wonderful post up about the evolution of giraffe necks, with the delightful snippet that until 1999 people thought they had fewer neck vertebrae than they do.
I can't add to the biology, so allow me to make a few comments about the role of the giraffe in the history of biology.
In the middle ages, the giraffe was known to most Europeans only by travellers' reports, and from classical times it was called the "cameleopard", as it was thought to be a hybrid between a camel, which was a familiar enough animal, at least to the eastern Mediterranean Europeans, and…
clock | February 2, 2007I guess I will bug you about this for the next ten days - my personal pet cause if you want. No takers yet....
Here is the e-mail newsletter about it I got today:
Dear All,
Beagle Project updates:
⢠We are now a UK registered company and have applied for charitable
status; now that we officially exist and are accountable we have
started fundraising,
we have paypal donate buttons on the
Homepage and weblog page:
www.thebeagleproject.com
www.thebeagleproject.com/beagleblog.html
we're asking individuals for a Darwin (£10) or a Jackson ($20 - he was
US President at the time of the voyage.…
evolvingthoughts | February 2, 2007
Recently, John Lynch mentioned a short passage in a book by historian Peter Dear, called The intelligibility of nature. Dear wrote this:
It is one of the remarkable facts about nineteenth-century natural history that the practices of taxonomists were not thrown into disruption by the eventual publication and acceptance of Darwin's ideas after 1859. Darwin was to rely on taxonomy for much of his argument in Origin of Species, reinterpreting its meaning in terms of the branching theory of descent. He never paused to ask whether the very meaning of the category "species" might have been…
evolvingthoughts | February 2, 2007
Canadian blogger, columnist and science fiction writer Ed Willett has a nice piece on some taxonomic jokes that have a point, entitled Lazarus, Elvis, zombies and Jimmy Hoffa. It's also a column in the Regina Leader-Post, which speaks well of Canadian media.
Willett discusses "Lazarus taxa", which are taxonomic groups that are found , either today or as fossils, long after the first instances become unrecorded in the fossil record. The star example of this is the Coelocanth. He gives a good short introduction to Linnaean systematics.
He mentions also Elvis taxa, which are taxa that look…
clock | February 1, 2007I first saw about this on Pharyngula the other day and I think it is a majestic idea! A group of Brits are trying to build a replica of HMS "Beagle" and, on the Darwin Bicentennial in 2009, sail around the world following the exact path Charles Darwin made on his historic voyage. Have scientists, journalists and, yes, bloggers, on board who will do research, take pictures and videos, and write their ship-logs for everyone to read (if a ship-log is on a blog, is it called shlog?). Stop at every port and promote evolution!
Most definitely take your time to check out their website and blog…
pharyngula | January 31, 2007I was thinking of doing something with this paper, but dang it, Omics! Omics! beat me to it. Read it anyway…I suppose there might be some other science in the universe left for me.
evolvingthoughts | January 31, 2007
I didn't know my dad all that well. He died when I was 11, after a long illness that saw him in hospital for nearly 5 years, and he didn't show much evidence that he liked me much. All we ever shared was a love of science fiction.
I'm a father myself, of two wonderful kids, but I feel deeply the lack of a relationship, as a kid or as an adult, with my father. I have tried to be to my kids the father I wanted, and in so doing, made many mistakes. The lack of role models, of experience of father-ness, left me trying to work it out for myself.
The other night, I saw a documentary on…
jrosenhouse | January 31, 2007It's been a while since I've replied to anything over at Uncommon Descent. But this entry from Salvador Cordova really caught my eye.
It is based on this paper, by mathematician Gregory Chaitin, The paper's title: “The Halting Probability Omega: Irreducible Complexity in Pure Mathematics.”
Goodness! There's irreducible complexity again. Let's check in with Salvador first:
On the surface Chaitin's notion of Irreducible Complexity (IC) in math may seem totally irrelevant to Irreducible Complexity (IC) in ID literature. But let me argue that notion of IC in math relates to IC in physics…
loom | January 31, 2007Speaking of hobbits, the paperback edition of my human evolution book is just about to come out, and you can order it now on Amazon. And if you prefer the resounding thwack of hard covers, the hardback edition is still available. For information on the innards of the book, see this post from last year.
evolvingthoughts | January 31, 2007
Can't talk. Eating. Paper. Grant application. Start of School Year for Son. Eating...
Reading this:
"Making Sense of Evolution: The Conceptual Foundations of Evolutionary Biology" (Massimo Pigliucci, Jonathan Kaplan)
and this:
"Darwinian Reductionism: Or, How to Stop Worrying and Love Molecular Biology" (Alex Rosenberg)
Do likewise...
oracknows | January 31, 2007There I was, puttering around the Internet trying to procrastinate while writing yet another grant, when I came across a truly inane article by Scott Adams arguing that the entire universe must be intelligent because processes that lead to products of intelligent (machines, books, etc., made by us) must also be intelligent. (At least I think that's what he was arguing; the argument was so poorly constructed and circular that it was hard to tell. No doubt Adams will retreat to his "I was only joking" or "I was only playing with your mind" defense.) I thought of having a little fun with it, but…