Biologists Find an Evolutionary Facebook for Monkeys and Apes
Nov. 18, 2013 — Why do the faces of some primates contain so many different colors — black, blue, red, orange and white — that are mixed in all kinds of combinations and often striking patterns while other primate faces are quite plain?
UCLA biologists reported last year on the evolution of 129 primate faces in species from Central and South America. This research team now reports on the faces of 139 Old World African and Asian primate species that have been diversifying over some 25 million years.
500,000-Year-Old Neanderthal Viruses Found in Modern Human DNA —(Did We Interbreed?)
Neanderthal viruses dating back 500,000 years has been discovered in modern human DNA when scientists studied links between ‘endogenous retroviruses’, which are hard-wired into DNA, and modern diseases such as AIDs and cancer. The researchers compared DNA from Neanderthals and another group of ancient humans called Denisovans with that obtained from cancer patients and found evidence of Neanderthal and Denisovan viruses in modern DNA, suggesting they shared a common ancestor more than 500,000 years ago. Neanderthals co-existed and possibly interbred with our ancestors in Europe for thousands of years, but belonged to a different sub-species, eventually becoming extinct around 30,000 years ago.
Approximately 8% of human DNA is made up of endogenous retroviruses, or ERVs, which are DNA sequences left by viruses which pass from generation to generation, forming part of the 90 per cent of the genome, sometimes called ‘junk’ DNA, that contains no instruction codes for making proteins.
Mimicry is common in nature, allowing an animal or insect to sneak in closer to prey or to dupe and deflect predators by taking on a more dangerous species’ characteristics. A fascinating example of the latter can be seen in the robber fly Wyliea mydas, which mimics lethal spider wasps, Pepsis formosa and Pepsis thisbe, known as tarantula hawks.
How Climate Change and Plate Tectonics Shaped Human Evolution
A new study links the emergence of new hominin species, expanding brain capacity and early human migration with the appearance of deep freshwater lakes
It should not be a surprise that East Africa was a hotbed of evolution, because over the last five million years everything about the landscape has changed.
The extraordinary forces of plate tectonics and a changing climate have transformed East Africa from a relatively flat, forested region to a mountainous fragmented landscape dominated by the rapid appearance and disappearance of huge, deep-water lakes. And from this highly variable landscape emerged an ape smart enough to question its own existence.
Monkeys ‘Understand’ Rules Underlying Language Musicality
Nov. 13, 2013 — Many of us have mixed feelings when remembering painful lessons in German or Latin grammar in school. Languages feature a large number of complex rules and patterns: using them correctly makes the difference between something which “sounds good,” and something which does not. However, cognitive biologists at the University of Vienna have shown that sensitivity to very simple structural and melodic patterns does not require much learning, or even being human: South American squirrel monkeys can do it, too.
EVERY KNOW WHAT IS THE DIFFERENCE BETWEEN MYSTICETI AND ODONTOCETI??
The cetaceans—whales, dolphins, and porpoises—are the most highly evolved, fully aquatic marine mammals, and make up 2 percent of the 4,600 living mammal species.
Dolphins belong to the suborder Odontoceti, or “toothed” cetaceans. Toothed whales are divided into ten families grouped into Three “superfamilies”: Delphinoidea, or oceanic dolphins, porpoises, and monodontids such as the beluga whale; Ziphoidea, or beaked whales; and Physeteroidea, or sperm, pygmy sperm, and dwarf sperm whales.
The other suborder of cetaceans, Mysticeti, comprises eleven species of whales which have baleen plates instead of teeth.
Toothed whales also differ from baleen whales in having a single (instead of a double) blowhole, a highly specialized echolocation system, and a pronounced forehead, or melon.
Toothed whales make up the vast majority of cetaceans. Approximately seventy one diverse species range from the relatively tiny vaquita, or Gulf of California harbor porpoise, which weighs in at about 120 pounds (about 50 kg) and is roughly 5 feet (about 1.5 m) long, to the well-known bottlenose dolphin, white beluga whale, and magniﬁcent killer whale (the largest dolphin) on up to the largest toothed whale, the sperm whale, which can reach 55 feet (18 m) in length. The terms porpoise, whale, and dolphin are often used interchangeably, but size (speciﬁ cally length) is the criterion anatomists have generally used to apply the common name whale.
Porpoises, members of the family Phocoenidae, differ from dolphins in several characteristics. Typically smaller, they also lack a pronounced rostrum (beak) and have shorter, spade-shaped teeth as opposed to dolphins’ more conical, pointy teeth.
RNA Controls Splicing During Gene Expression, Further Evidence of ‘RNA World’ Origin in Modern Life
Nov. 6, 2013 — RNA is the key functional component of spliceosomes, molecular machines that control how genes are expressed, report scientists from the University of Chicago online, Nov. 6 in Nature. The discovery establishes that RNA, not protein, is responsible for catalyzing this fundamental biological process and enriches the hypothesis that life on earth began in a world based solely on RNA.
"Two of the three major processes in eukaryotic gene expression — splicing and translation — are now shown to be catalyzed by RNA," said Jonathan Staley, PhD, associate professor of molecular genetics and cell biology at the University of Chicago and co-corresponding author on the study. "The eukaryotic gene expression pathway is more of an RNA-based pathway than protein-based."
Excited to announce the premiere of The Advanced Apes, a new science show from PBS Digital Studios.
In the first episode, Cadell Last explains how scientists realized that we’re all African (evolutionarily speaking), how we spread across the Earth, and how that is reflected in the continuing evolution of our species.
Excited to share the YouTubes with Cadell and The Advanced Apes!
Evolution of new species requires few genetic changes
Only a few genetic changes are needed to spur the evolution of new species—even if the original populations are still in contact and exchanging genes. Once started, however, evolutionary divergence evolves rapidly, ultimately leading to fully genetically isolated species, report scientists from the University of Chicago in the Oct 31 Cell Reports.
"Speciation is one of the most fundamental evolutionary processes, but there are still aspects that we do not fully understand, such as how the genome changes as one species splits into two,” said Marcus Kronforst, Ph.D., Neubauer Family assistant professor of ecology and evolution, and lead author of the study.