evolution
clock | January 11, 2007Continuing with the Thursday series of the BIO101 lecture notes. Check for errors of fact. Suggest improvements (June 01, 2006):
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BIO101 - Bora Zivkovic - Lecture 4, Part 1
Adaptation vs. Diversity
Biology is concerned with answering two Big Questions: how to explain the adaptation of organisms to their environments and how to explain the diversity of life on Earth.
Much of the course content so far engaged the question of the origin and evolution of adaptation, and much of the remainder of the course will also look at particular adaptations of humans…
mikethemadbiologist | January 10, 2007Over at DailyKos, Darksyde comments on the motivations of the Kansas creationists (italics mine):
It's easy to get lost in the scientific or religious discussion, but this isn't about evolution or science or even religion. It's just another right-wing funded attack on behalf of the mega-rich, cleverly packaged to appeal to the very working families whose future it will devastate. The real goal is to undermine confidence in public education, maybe ultimately replacing those institutions with privatized versions (No doubt run by a recently acquired subsidiary of Neoconia Inc., suckling at the…
loom | January 9, 2007Cancer, many biologists aruge argue, is an evolutionary disease. It is a burden of being multicellular, and a threat against which natural selection has only managed mediocre defenses. Making matters worse, cancer cells can borrow highly evolved genes for their own deadly purposes. And even within a single tumor, cancer cells get nastier through natural selection.
I've been following the study of evolution and cancer for some time now, and have blogged on the Loom about it here, here, and here. But it was a review in Trends in Ecology and Evolution that spurred me to launch a full-blown…
evolgen | January 9, 2007Via Snail's Tails comes this podcast (dated 05 January 2006 on this page) featuring E.O. Wilson. According to Aydin (I'm a blogger so I don't fact check my sources) Wilson lays out the two fundamental laws of biology:
All of the phenomena of biology are ultimately obedient to the laws of physics and chemistry.
All of the phenomena of biology have arisen by evolution thru natural selection.
Everything in biology is the product of evolution. Only some biological phenomena can be attributed to natural selection. The issue of neutral versus selected (and within selected we have constrained…
clock | January 8, 2007Science Daily should know better. The title is OK:
Annual Plants May Cope With Global Warming Better Than Long-living Species
But look at the first sentence:
Countering Charles Darwin's view that evolution occurs gradually, UC Irvine scientists have discovered that plants with short life cycles can evolutionally adapt in just a few years to climate change.
Excuse me, but there is nothing there countering Darwin, or countering gradual evolution!
They are mixing two senses of the word "slowly". Under the same strength of selective pressure, all organisms will evolve at the same rate. That…
grrlscientist | January 8, 2007According to a recent news story, two NASA space probes that visited Mars in 1976 and 1977 might have discovered life there, but then killed it, according to a hypothesis presented by Dirk Schulze-Makuch at a meeting of the American Astronomical Society (AAS) in Seattle, Washington. This is based on the fact that the probe was only seeking earth-like life;
Given the cold dry conditions of Mars, life could have evolved on Mars with the key internal fluid consisting of a mix of water and hydrogen peroxide, said Schulze-Makuch.
That's because a water-hydrogen peroxide mix stays liquid at very…
pharyngula | January 8, 2007
As we are so often reminded by proponents of Intelligent Design creationism, we contain molecular "machines" and "motors". They don't really explain how these motors came to be other than to foist the problem off on some invisible unspecified Designer, which is a poor way to do science—it's more of a way to make excuses to not do science.
Evolution, on the other hand, provides a useful framework for trying to address the problem of the origin of molecular motors. We have a theory—common descent—that makes specific predictions—that there will be a nested hierarchy of differences between…
oracknows | January 7, 2007I like this T-shirt design!
Perhaps our Seed overlords would spring for sufficient funds to clothe all of us ScienceBloggers in this fine garb.
(Via Boing Boing.)
pharyngula | January 6, 2007Everyone can stop now, my brain is full. Seriously, this is a painful meeting: my usual strategy at science meetings is to be picky and see just a few talks in a few sessions, to avoid burnout…but at this one, I go to one session and sit through the whole thing, and at the breaks I look at the program and moan over the concurrent sessions I have to be missing. I have to come to SICB more often, that's for sure.
I do have one major complaint, though: PowerPoint abuse. The evolution of slides has continued apace since my graduate school days, when one slide was one photograph, developed in a…
evolvingthoughts | January 4, 2007PEER, a website devoted to promoting environmental responsibility by public institutions, notes that three years after promising to review the literature on display at the Grand Canyon National Park after creationist literature was on offer, nothing has happened.
In fact, the National Park Service has refused to say anything about the age or formation of the canyon, due to pressure from Bush appointees. It seems geology cannot be allowed to interfere with the religious supporters of the Bush gang.
Hattip to John Pieret.
Update: The Sacrameto Bee gives some of the background and developments…
pharyngula | January 4, 2007Here's what I heard this morning. Wonderful stuff, all of it, and I'm having a grand time. This is a quick summary, and now I have to rush back to the meeting for more.
S. Kuratani: Craniofacial evolution from a developmental perspective. This was a lamprey and hagfish talk, comparing them to vertebrates. Hox gene expression patterns in lamprey, which assign anterior-posterior positional information, are very similar to those in vertebrates, but there is no temporal colinearity—timing is all over the place. There is no apparent dorsal-ventral patterning of Dlx gene expresion. They've…
evolvingthoughts | January 2, 2007Mark Vernon, at the Guardian's blog site, asks what would happen to theology if Corot finds evidence of inhabited planets (which it won't, because it's not set up for that). He raises the traditional theological concerns, made popular in C. S. Lewis' Perelandra series. But then he makes the following mistake.
The scientifically-minded should be careful before using such a reductio ad absurdum as another stick with which to beat Christianity. For life on other planets would set science in a spin, too. Take Darwinism. Although evolutionary theory is mute on how life started, it does suggest…
jlynch | December 29, 2006The November 30th edition of the London Review of Books has a review by John Whitfield of Burt & Trivers' Genes in Conflict: The Biology of Selfish Genetic Elements (which has been on my shelf unread for awhile now). Here's a nice quote:
[R]eading [the book] did help me work out why evolutionary biology is so compelling. It's because it is to biology what maths is to physics: a set of beautiful and powerful intellectual tools that unify and make sense of the facts, revealing both life's strangeness and its logic.
evolgen | December 29, 2006The rift in the biological sciences may lie between computational biologists and wet labs, but when we look at individual fields, we see other divisions. In an essay in PLoS Computational Biology Carl Zimmer describes the divide amongst evolutionary biologists. On one side are researchers who like to get their hands dirty -- ecologists, paleontologists, and others that fall under the label 'naturalist'. And on the other side we have the people that prefer to work with molecular tools; Zimmer calls these guys computational biologists, but they also generate their own data, so that label isn't…
loom | December 29, 2006One reason I love writing about biology is that it has so many levels. Down at the molecular scale, proteins flop and twist. Higher up, cells crawl and feed and divide. They organize into animals and plants and other big organisms, which must obey their own rules in order to survive. For some organisms, a day is a lifetime. Others must weather centuries. When millions of organisms get together, they form ecosystems that wax and wane in ways that could not be predicted from lower levels. And over the course of generations, genes take on a new personality, no longer passive bits of code, but…
mikethemadbiologist | December 29, 2006After reading this article about Democratic consultant Mara Vanderslice whose speciality is outreach to "theological conservatives", my head was about to explode. Thankfully, digby points out that courting social conservatives will make the Democratic Party, well, more conservative--or as a relative put it, "There's always a quid pro quo." And Jonathan Singer explodes the myth that it was social conservatives who elected Democrats (maybe if Vanderslice were a little less faith-based and a little more reality-based, she would understand what a control group is). But this statement by…
jlynch | December 28, 2006I don't really have time to write anything on this at the moment as I'm busy with another project, but I will note that American Naturalist is making available an interesting paper that uses the AVIDA system to study ecological specialization in digital organisms.
The transition from generalist to specialist may entail the loss of unused traits or abilities, resulting in narrow niche breadth. Here we examine the process of specialization in digital organisms--self-replicating computer programs that mutate, adapt, and evolve. Digital organisms obtain energy by performing computations with…
pharyngula | December 27, 2006Allow me to introduce you to a whole gigantic superclade with which many of you may not be familiar, and some other groups in the grand hierarchy of animal evolution that I've mentioned quite a few times before, but would like to clear the fog with some simple definitions. Consider this a brief primer in some major animal groupings. Here's a greatly simplified cladogram; I've left off quite a few groups to make the story simple.
I have a frequently admitted bias: I'm most interested in the evolution and development of the Metazoa, or the multicellular animals. I don't follow the literature…
jlynch | December 26, 2006
Today in 1831, Charles Darwin left Plymouth on board the HMS Beagle for a voyage that would be epoch-making in the history of science. He would return to England on the 2nd of October 1836. In 1837 he would begin a series of notebooks that would culminate in his 1842 "pencil sketch" of his theory of transmutation through natural selection.
evolgen | December 26, 2006John Wilkins has replied to Larry Moran on the role of "chance" in evolution (incidentally, Moran replies to Wilkins on the same topic, but a different post by Wilkins). Here's what Larry wrote:
Nobody denies the power of natural selection and nobody claims that natural selection is random or accidental. However, the idea that everything is due to natural selection is the peculiar belief of a relatively small number of people, of whom Richard Dawkins is the most outspoken.
A great deal of evolution is the result of chance or accident, as is a great deal of the rest of the universe. It's…