Evolution
For life to begin, there had to be a source of organic compounds in the prebiotic environment. We now think that some of the compounds were delivered to the Earth on comets, meteorites and dust particles, but others were synthesized in the atmosphere, hydrosphere and in volcanic conditions. How do we know? This question brings up the important topic of prebiotic simulations. In a simulation, we make a set of assumptions about local conditions on the early Earth, then reproduce those conditions in the laboratory and run experiments to see what happens. The results of…
I have been putting together a free resource about evolution which I am proud to say is now up at www.evolverzone.com.
jdennehy |
I was fascinated by the discovery of the dwarfed hominin Homo floresiensis back in 2004 when it was first announced, but was skeptical that it was really a separate species. Later when I saw a cast of the skull, I admit to being more enthused with the possibility of a new species. Not being a anthropologist, I couldn't discount the possibility of microcephaly and/or dwarfism.
However, a recent pair of articles in Nature discount this possibility, and I'm convinced. Jungers et al. analyzed the H. floresiensis foot and report that it is quite unhumanlike. For a meter-high hominin, it sure has a…
iramjohn |
It's hard not to see the world through the lens of our own preconceptions and biases. We tend to be more interested in other large mammals. We're drawn to human-like qualities in pets. But even the most benign insect is disturbingly alien when seen up close. We also tend to use the familiar as a metaphor for understanding the unfamiliar. Sometimes this gives us additional insight. Other times, it leads us down the wrong path.
Most of us are familiar with mosses, even though we tend to use it as a catch-call term for any of the green 'gunk' that grows in…
Altruism has had a lot of bad press in recent times. It’s been used, abused, manipulated and misunderstood. Let’s look at some background.
It all began with a paper submitted by WD Hamilton in 1964 in which he put forward a view of altruism that was packaged into a concept called inclusive fitness. Inclusive fitness became the bedrock of selfish gene theory, because it was assumed that it solved “the problem” of altruism, a problem that had to be solved for evolution-as-selfishness to get off the ground. But it led to unforeseen problems of its own.
In a footnote to The God Delusion Richard…
In a recent study (that yielded some exceptionally interesting results), catalytic RNA molecules were used in order to advance the understanding of Darwinian evolution. Researchers Dr. Sarah Voytek and Professor Gerald Joyce of the Scripps Research Kellogg School of Science and Technology, choose RNA molecules because they evolve rapidly and self-replicating RNA molecules are hypothesized to be the first organic “life forms” on earth. With a trillion molecules in a test tube replicating every few minutes, such an approach permits evolution to occur over the course of just a…
Many people, perhaps most, hate the idea that life might depend on chance processes. It is a human tendency to search for meaning, and what could be more meaningful than the belief that our lives have a greater purpose, that all life in fact is guided by a supreme intelligence which manifests itself even at the level of individual molecules? Proponents of intelligent design believe that the components of life are so complex that they could not possibly have been produced by an evolutionary process. To bolster their argument, they calculate the odds that a specific protein might assemble…
An ancient protein dating back 80 million years to the Cretaceous period has been preserved in bone fragments and soft tissues of a hadrosaur - a duck-billed dinosaur - according to a study in the May 1 issue of Science. The new findings support earlier results from analyses suggesting that collagen protein survived in the bones of a well preserved Tyrannosaurus rex, and offer new evidence supporting previous conclusions that birds and dinosaurs are directly related. In April 2007 John Asara, PhD, Director of the Mass Spectrometry Core at BIDMC, together with NCSU paleontologist Mary…
Have we really stopped evolving? In Cosmos magazine, Steve Jones argues that human evolution is coming to an end:
The question I have is: will human evolution really continue? I think the evidence shows that human evolution has largely come to a halt.
He lists three components necessary for human evolution:
First of all there's variation, which comes from mutation. Second, natural selection, which comes from inherited differences between individuals and their ability to reproduce.Finally, evolution is greatly promoted by isolation.
Jones is right about the first two elements: you need…
A new study challenges long-standing expectations that men are promiscuous and women tend to be more particular when it comes to choosing a mate. The research in Trends in Ecology and Evolution suggests that human mating strategies are not likely to conform to a single universal pattern and provides important insights that may impact future investigations of human mating behaviors.
In 1948, Angus J. Bateman's performed some now famous studies in fruit flies that showed that males exhibit greater variance in mating success (the number of sexual partners) and in reproductive success (the number…