YouTuber Retic over at Prehistoric Pets TV has a huge collection of pythons and other ancient creatures. Here he shows how and why a clutch of python eggs can be lifted up in giant sticky clumps. Read the rest
Yeast has brought a lot of joy into the world, but its evolutionary origins were unclear until scientists did a worldwide genomic survey of the humble organism. Based on the genetic diversity of strains found in China, they concluded that its origin is almost certainly in that part of the world. Read the rest
In many, animal species are domesticated when humans bring them into their homes whether they want to be there or not. For example, it's mostly accepted that humans domesticated wolves, breeding them in captivity until they became the modern dogs we love today. Now, a new study of cat genetics reveals that cats just kind of hung around humans for thousands of years before they were domesticated. From Casey Smith's article in National Geographic:
Read the rest
The earlier ancestors of today’s domestic cats spread from southwest Asia and into Europe as early as 4400 B.C. The cats likely started hanging around farming communities in the Fertile Crescent about 8,000 years ago, where they settled into a mutually beneficial relationship as humans’ rodent patrol.
Mice and rats were attracted to crops and other agricultural byproducts being produced by human civilizations. Cats likely followed the rodent populations and, in turn, frequently approached the human settlements.
“This is probably how the first encounter between humans and cats occurred,” says study coauthor Claudio Ottoni of the University of Leuven. “It’s not that humans took some cats and put them inside cages,” he says. Instead, people more or less allowed cats to domesticate themselves.
A second lineage, consisting of African cats that dominated Egypt, spread into the Mediterranean and most of the Old World beginning around 1500 B.C. This Egyptian cat probably had behaviors that made it attractive to humans, such as sociability and tameness.
The results suggest that prehistoric human populations probably began carrying their cats along ancient land and sea trade routes to control rodents.
Research suggests that people who do nice things for others, often at a cost for themselves, are more sexually attractive. From an evolutionary perspective, this might be because altruism indicates that a potential mate is more cooperative and caring. Evolutionary psychologists Steven Arnocky, at Nipissing University, and Pat Barclay, at the University of Guelph, conducted a fascinating study to explore whether altruistic people really do have more sexual partners. From Scientific American:
Read the rest
This theory suggests that altruism may serve, in part, to convey one’s value as a mating partner, including one’s concern for others and likelihood of cooperating with future mates. Research has shown that we prefer altruistic partners, all else being equal; especially for long-term mating (the evidence for altruism being preferred in short-term mates is mixed). Not surprisingly, then, the pull to demonstrate one’s altruism can be strong. Some research has shown that men will actively compete with one another (termed competitive altruism) by making charitable donations to women. Interestingly, these charitable donations increase when the target of one’s altruism is physically attractive...
Previous findings from hunter-gatherer populations have shown that men who hunt and share meat often enjoy greater reproductive access to women. But do these links hold up in other cultural and contextual arenas, such as in contemporary North American society? To find out, we conducted a set of two studies. In our first study, undergraduate men and women completed an altruism questionnaire (involving questions like “I have donated blood”), along with a sexual history survey. Participants also completed a personality inventory, given the possibility that those with certain personality characteristics (such as being extroverted) might happen to engage in both more altruism and more sexual activity.
Craig Froehle tracks the odd convolutions of his famous illustration of how conservatives and liberals view the notion of equality. It's been simplified, expanded, twisted, tucked in and turned inside-out—and even redrawn by professional artists.
Are the worst versions the ones that bury the simple point in condescending explanation?
Or the ones that seek to subvert it entirely, in as much as stamping "THIS IS FUCKING STUPID" over it counts as subversion?
The cannier mutations contextualize it for local audiences:
Read the rest
I am giddy that my little graphic has helped so many people think about the issue of equity and has spawned so many conversations in just the past few years. I’m not upset by the many way it’s been reimagined. In fact, I’m delighted, because the modifications just make it that much more useful to people.
A paper published this summer looked into over 100 times humpbacks were observed disrupting orcas who are hunting, like these humpbacks trying to save a gray whale and calf. But why do they do it? Read the rest
Trees of Life: A Visual History of Evolution
by Theodore W. Pietsch
Johns Hopkins University Press
2013, 376 pages, 8 x 10 x 1.1 inches (softcover)
Starting at $22 Buy a copy on Amazon
The primary metaphor for visualizing evolution is as a tree. The trunk is the oldest ancestor species which branch off newer species, which branch further leaves of the newest species. Ever since Darwin, biologists have been drawing trees to attempt to capture the complexity of evolution in various domains. These evolutionary trees are not only scientifically useful, but works of art. Over the years, many approaches to the trees have been tried – some minimal, some ornate, some abstract. This tome collects the finest, most unusual, most beautiful evolutionary tree maps produced in the last 200 years. They not only inform biology, they are fantastic examples of great design.
Language Evolution Simulation is exactly that, showing words changing little by little as time passes in a tiny world with three islands. It's agent-based, which is to say that it models little computer folk interacting with one another to simulate the little mutations that add up over time.
If an agent intersects with another, selects a word from the own vocabulary and tells that. The neighborhood receives and adds that word into its vocabulary as
- Mutation of a vowel sound with 0.1 probability
- Mutation of a const sound with 0.1 probability
- Compounding with another word with 0.1 probability
- Without any mutation
There's nothing to do but watch words change, but it feels like the underpinning of a very strange computer game about culture.
I love agent-based models; check out this simulation of political cliques I made. It randomly generates several personalities, who then go around and bicker or flatter one another. It's very bland and primitive, made in Flash, and the "next turn" text is rather fiddly to click. But I've always had plans on expanding it into a more fully featured game.
The origin of dogs is a hot topic among biologists, who've fought over whether there's a single point of origin from wolves and when and where it (or they) happened. A new study suggests the answer is twice, independently, from populations of wolves in western Europe and in east Asia. But they interbred, so most modern dogs are descended from both western and eastern groups.
Read the rest
The geographic and temporal origins of dogs remain controversial. We generated genetic sequences from 59 ancient dogs and a complete (28x) genome of a late Neolithic dog (dated to ~4800 calendar years before the present) from Ireland. Our analyses revealed a deep split separating modern East Asian and Western Eurasian dogs. Surprisingly, the date of this divergence (~14,000 to 6400 years ago) occurs commensurate with, or several millennia after, the first appearance of dogs in Europe and East Asia. Additional analyses of ancient and modern mitochondrial DNA revealed a sharp discontinuity in haplotype frequencies in Europe. Combined, these results suggest that dogs may have been domesticated independently in Eastern and Western Eurasia from distinct wolf populations. East Eurasian dogs were then possibly transported to Europe with people, where they partially replaced European Paleolithic dogs.
“The avocado is highly regarded by many people as delicious and nutritious, but the most extraordinary thing about avocados may be their very existence.” Read the rest