Evolution
This should be a good read:
Understanding Climate's Influence on Human Evolution
The hominin fossil record documents a history of critical evolutionary
events that have ultimately shaped and defined what it means to be
human, including the origins of bipedalism; the emergence of our genus
Homo; the first use of stone tools; increases in brain size; and the
emergence of Homo sapiens, tools, and culture. The Earth's geological
record suggests that some evolutionary events were coincident with
Dogs likely originated in the Middle East, according to a new genetic analysis published this week in Nature.
The study reports genetic data from more than 900 dogs from 85 breeds and more than 200 wild gray wolves (the ancestor of domestic dogs) worldwide, including populations from North America, Europe, the Middle East and East Asia. Researchers used molecular genetic techniques to analyze more than 48,000 genetic markers.
The data include samples from Israel, Saudi Arabia and Iran — but they have not pinpointed a specific location in the Middle East where dogs originated.
A study of blind scorpions published in Cladistics is challenging the long-held assumption that specialized adaptations are irreversible, evolutionary dead-ends.
According to the new phylogenetic analysis of the family Typhlochactidae, scorpions currently living closer to the surface (under stones and in leaf litter) evolved independently on more than one occasion from ancestors adapted to life further below the surface (in caves).
Scorpions are predatory, venomous, nocturnal arachnids that are related to spiders, mites, and other arthropods. About 2,000 species are distributed throughout the world, but only 23 species found in ten different families are adapted to a permanent life in caves. These are the specialized troglobites.
I seem to have developed a reputation for hating networks, but really, it's just tough love. Complex, adaptive, self-organizing networks are fascinating (and inspired the title of this blog), and they deserve a rigorous scientific treatment. Decentralized control mechanisms are incredible, and, although they're all around us, they go completely against our instincts for good, hierarchical design for control systems. How does a cell adapt to environmental signals, in the absence of a brain or CPU? And how do we make our own, human-built networks as self-adaptive and robust as biological ones? In other words (for those of you who've endured lengthy lectures on the subject in physiology class), how do you effectively engineer homeostasis?
Check out the
Super Star Edition at Mauka to Makai, which, this month, is almost as exciting as watching Shaun White and Apolo Ohno.
There are a bunch of posts commemorating Darwin's birthday, which note his obsession with Barnacles, his efforts to decide between getting married and getting a dog, and how he was lampooned by Victorian cartoonists.
Read about shark evolution, smart crows, Archbishop Desmond Tutu's genome, teaching evolution and more. With each issue of the Carnival of Evolution, I discover great blogs I've missed or forgotten about. Go check it out.
Read the feed:
the 47-million-year-old Darwinius masillae fossil that was celebrated last year as a so-called 'missing link' between humans and early primates is actually a forebearer of modern-day lemurs and lorises, according to two papers in the Journal of Human Evolution and PNAS.
Researchers note in one article published in the Journal of Human Evolution that Darwinius masillae is not a haplorhine primate like humans, apes and monkeys, as the 2009 research claimed. They also note that the article on Darwinius published last year ignores two decades of published research showing that similar fossils are actually strepsirrhines, the primate group that includes lemurs and lorises.
Researchers analyzing mitochondrial DNA extracted from a polar bear fossil discovered in Norway in 2004 say the species is relatively young, splitting off from brown bears approximately 150,000 years ago and rapidly evolving during the late Pleistocene. The findings are published in the Proceedings of The National Academy of Sciences
"Very few polar bear fossils have been found, leading to widely varying estimates of exactly when and how polar bears evolved," explains Øystein Wiig, polar bear expert and co-author at the University of Oslo's Natural History Museum. "Because polar bears live on the ice, their dead remains fall to the bottom of the ocean or get scavenged. They don't get deposited in the sediments like other mammals."
Researchers who observed viruses as they evolved to infect bacteria say they have confirmed the Red Queen Hypothesis, the idea that competing species drive molecular evolution through natural selection for adaptation and counter-adaptation.
The team used high-throughput DNA sequencing technology to sequence thousands of virus genomes. They found that when the bacteria could evolve defenses, the viruses evolved at a quicker rate and generated greater diversity, compared to situations where the bacteria were unable to adapt to the viral infection. The results are published in Nature.
Promiscuous females may be the key to a species' survival, according to new research published today in Current Biology. The study may explain why females of most species have multiple mates, despite this being more risky for the individual.
Known as 'polyandry' among scientists, the phenomenon of females having multiple mates is shared across most animal species, from insects to mammals. This study suggests that polyandry reduces the risk of populations becoming extinct because of all-female broods being born.