Life Sciences

In this entry, I will deal only with the brief note that Rusty Lopez made in reference to a testable creation model. In the next few days, I'll post a longer and more detailed critique of the model presented by Hugh Ross that Rusty referenced in his note. I'll put his statements in italic and my own responses in plain type. A Scientifically Testable Creation Model...How is this possible? Are we saying that science can prove creation? No. Reasons to Believe is saying that we can test the predictions made by competing scientific models. We can at least begin with an area of agreement. Testing a…
The emotions that other species summon up in the human brain are perplexing. A lion inspires awe and respect. It is the king of the jungle, a great name for a football team, a noble guardian of the entrance to the New York Public Library. A tapeworm, on the other hand, summons disgust mixed with a little contempt. You will never find yourself cheering for the Kansas City Tapeworms. But are these species really so different? Both animals get their nutrition from the bodies of other animals, and tapeworms are arguably more sophisticated in the way they get their food than a lion. Tapeworms…
Last week I briefly mentioned some stark estimates about the potential extinctions that could be triggered by global warming. Since then, some global warming skeptics have tried to pour cold water on these results by making some dubious claims about natural selection and extinctions. While I have reported about global warming from time to time, I leave blogging on the subject to others (particularly David Appell over at Quark Soup). But in this case, evolution is drawn into the mix. Here, in a nutshell, is what the scientists wrote last week in their Nature paper (which the editors have made…
Evolution isn't simply about the genes you gain. It's also about the genes you lose. The word loss has a painful, grieving sound to human ears, and so it can be hard to see how it can have anything to do with the rise of diversity and complexity in life. And until recently, evolutionary biologists didn't pay much attention to lost genes because they were preoccupied with the emergence of new ones. New genes, they found, can be produced in many ways. A gene can get accidentally duplicated, for example, and the copy can mutate, taking on a new function. Or pieces of two separate genes can get…
Darwin's spirit lives on in everything from the Human Genome Project to medicine to conservation biology--the three topics I covered in my post on Friday. It also lives on in brain scans. While Darwin is best known for The Origin of Species, he also wrote a lot of books in later years, most of which explored some aspect of nature that he showed revealed the workings of evolution. His examples ranged from orchids to peacock tails. In his 1872 book, The Expression of the Emotions in Man and Animals, he proposed that the expressions we humans use--our smiles, our frowns, and so on--are part of a…
Time always marches forward, of course, but does evolution? It's certainly easy to impose a march of progress on the course of evolution. That's why the sequence of apes transforming into humans as they march from left to right is so universal. Of course, there are also pictures in which Homo sapiens, having risen up to noble, upright proportions, begins to crouch back down again, until he (never a she, I've noticed) is crouching in front of a computer or a television or facing some other ignoble end. As I wrote in Parasite Rex, this anxiety--an anxiety mostly about ourselves and not about…
The other day I (among others) came down on Gregg Easterbrook for his poor grasp of science. Finding myself procrastinating today, I wandered over to his blog and had yet another good laugh. In a post today, he actually displays some interest in evolutionary biology. After discussing some work suggesting that wine might be able to prolong life, he gets into the evolution of longevity. I raised my eyebrows at this point, thinking perhaps he'd moved away from the muddled stuff he's written about evolution in the past. But then the goofiness returns. First he describes how experiments to extend…
Evolution is nature's great R&D division. Through mutation, natural selection, and other processes, life can find new solutions for the challenge of staying alive. It's possible to see a simplified version of this problem solving at work in the lab. The genetic molecule RNA, for example, can evolve into shapes that allow it to do things no one ever expected RNA to do, like join together amino acids. Over millions of years, evolution can solve far bigger problems. How can a mammal became an efficient swimmer? How can a bug fly? Humans would like to build ocean-going vehicles as efficient…
When Charles Darwin was thrashing out his theory of evolution, he would doodle sometimes in his notebooks. To explain how new species came into existence, he wrote down letters on a page and then connected them with branches. In the process, he created a simple tree. Across the top of the page, he wrote, "I think." That single tree has given rise to the thousands of trees that are published in scientific journals these days. A particular tree may show that humans are more closely related to chimpanzees than gorillas. It might show how the SARS virus in humans descends from viruses in other…
The Great Lakes of East Africa swarm with fish--particulary with one kind of fish known as cichlids. In Lake Victoria alone you can find over 500 species. These species come in different colors and make their living in many different ways--sucking out eyeballs of other cichlids, scraping algae off of rocks, and so on. What's strange about all this is that the Great Lakes of East Africa are some of the youngest lakes on Earth. By some estimates, Lake Victoria was a dry lake bed 15,000 years ago. All that diversity has evolved in a very short period of time. East African cichlids are therefore…
Thanks again for the comments on my previous two posts about eugenics. As a novice blogger, I was surprised by their focus. I expected comments about the past--the historical significance of the eugenics movement--but instead the future dominated, with assorted speculations about the possible futures that genetic engineering could bring to our species. By coincidence, I've been thinking about the future as well, but from a different angle, thanks to a pair of papers in press at Trends In Ecology and Evolution. Instead of introduced genes, they're interested in introduced species. Before…