Posts tagged biology.
Microbes in your body outnumber your cells by ten to one and can weigh as much as or more than your brain.
Photographed here with a microscope, the human mouth hosts an array of microbes. Take a look:http://on.natgeo.com/145iXDm
Human Body Tissue Types: (from left to right)
Skeletal Muscle - performs voluntary movements of the limbs, is arranged into bundles of fibres that connect to bones via tendons.
Adipose Tissue - a type of connective tissue that acts as an energy store and helps to cushion, protect and insulate the body.
Smooth Muscle - found in sheets on the walls of blood vessels, stomach, intestines and bladder. vital for maintaining blood pressure and for pushing food through the digestive system.
Spongy Bone - found in the centre of bones , the lattice-like spaces in spongy bone are filled with bone marrow or conective tissues.
Cartilage - found in the joints between bones and in the ear and nose. It is tough but flexible due to the high water content.
Dense Connective Tissue - occurs in the base layer of skin and forms structures such as ligaments and tendons.
Epithelial Tissue - forms a covering/lining for internal and external body surfaces. some epithelial tissues can secrete digestive enzymes while others can absorb substances such as food or water.
Nerve Tissue - forms the brain,. spinal cord, and the nerves that control movement, transmit sensation and regulate body function. Made up mainly of networks of nerve cells
Reference: Dr Alice Roberts, The Complete Human Body: The Definitive Visual Guide, 2010.
“Otzi” the Iceman. In his place of discovery in the Italian Alps.
This image almost saddens me. I always reblog Ötzi because he’s incredibly interesting as a specimen, because there is a great lot to learn about his preservation, age and history. I’m not assuming he died in this position and I understand many factors affect the positions corpses take perimortem and postmortem. However, he looks so alone in this image and in truth he died alone in the mountains. I can imagine him curling over on himself as he slowly died without his people around him. This image makes specimen Ötzi a touch more human Ötzi for me.
In 1876, British biologist Alfred Russell Wallace published a map of the world that outlined how related animals were spread over the Earth. For example, Wallace was the first to publicize that North American biodiversity was substantially different from South America, and that an invisible line separated Southeast Asian biodiversity from that of Australia, New Guinea, and nearby islands. With Wallace’s research came the founding of biogeography, or the study of species in relation to geography. Today, scientists with the University of Copenhagen have updated Wallace’s map—nearly doubling the number of biogeographic realms—with support from data on over 21,000 species….
With vast amounts of data, including DNA sequencing, the scientists have created new biogeographic realms, such as the island of Madagascar which is home to lemurs, tenrecs, mini-chameleons, and slew of other bizarre species. Still, much of Wallace’s original map survives, such as the split between North and South America, and the line—known as Wallace’s Line—separating Southeast Asia and Australia. However, the new study also splits Australia from New Guinea, creating a new biogeographic realm known as Oceania which includes New Guinea and other islands across the Pacific….
The map utilizes known data from 6,110 amphibians, 10,074 birds and 4,853 terrestrial mammals.
The new map is on top, and Wallace’s map is on the bottom.
Infographic by Mezzmer
TheScienceLllama sent this to me a while ago — very interesting! Thanks so much! And to answer your question… yes, I am a Nerdfighter and have been for years. I remember when Brotherhood 2.0 came out. THAT LONG.
How life’s energy was born in deep-sea rocks
ATP: The currency of life. It’s one of the first things we learn in intro biology classes. This energy-rich molecule, whose simple phosphate bonds contain the thermodynamic potential to drive a great deal of our biochemistry, stands with nucleic acids and proteins as molecular cornerstones of life on Earth.
But how did the enzymes that synthesize ATP arise? It’s sort of a chicken/egg problem. You need ATP (and other energetic molecules, like GTP) to make proteins, so how do you make proteins without ATP? The cell’s gorgeous ATP factory, ATP synthase, is the primary source, using the flow of hydrogen ions to manufacture new ATP molecules. Look how amazing this molecular machine is:
So where does that hydrogen ion energy originate? Today we have elaborate cellular pumps to create that “ion gradient”. A new theory presented in Cell might help resolve the hydrogen chicken/egg problem. Early proto-cells, created in porous rocks around hydrogen-rich undersea thermal vents, may have been able to steal hydrogen through the thin rocks to create their ATP, their rocky pores serving as tiny test tubes for the creation of early organic molecules.
Then, when they began to float freely in the sea after further evolution on the rocks, these proto-cells tweaked another ion transporter, a sodium pump, to help maintain the hydrogen gradient once they left their rocky evolutionary birthplace.
Ed Yong has more about this amazing “origin of life” story at Nature News.
Scientific American (2006)
Becoming Human: Evolution and Rise of Intelligence
This is one of my favorite, if not my favorite, issues from them since everything in this one is pure gold.
Planet of the Apes
David R. Begum
Bonobo Sex and Society
Frans B.M. de Waal
Diet and Primate Evolution
Why Are Some Animals So Smart?
Carel van Schaik
Stranger in a New Land
The Littlest Human
How We Came to Be Human
The Morning of the Modern Mind
The Emergence of Intelligence
William H. Calvin
I’m reblogging this because I don’t think you guys realise how AWESOME it is. And also this is a link to the ENTIRE ISSUE.
King of Saxony Bird-of-paradise
The King of Saxony Bird-of-paradise (Pteridophora alberti) is a bird in the Bird-of-paradise family (Paradisaeidae). It is the only member in the monotypic genus Pteridophora. It is endemic to montane forest in New Guinea.
Both the common name “King of Saxony” and the scientific specific name “alberti” were given to honour Albert of Saxony, whose wife gave her name to the Queen Carola’s Bird-of-Paradise. The bird is sometimes known as “Kisaba” by the natives of Papua New Guinea and Western New Guinea, as a human interpretation of the male’s loud call.
The diet consists mainly of fruits, berries and arthropods.
( read more )
damn nature, you crazy
South Africa plays a central role in the history of paleoanthropology. Anthropologists and other scientists of the 19th and early 20th century balked at the possibility that Africa was humankind’s homeland—until an ancient hominid was unearthed in South Africa in 1924. Since then, Africa has become the center of human evolution fieldwork, and South Africa has produced a number of iconic hominid fossils and artifacts. Here is a totally subjective list of the country’s most important hominid discoveries.
Taung Child: In 1924, anatomist Raymond Dart pried a tiny fossilized partial skull and brain from a lump of rock. The bones were the remains of a child. The youngster looked like an ape, but Dart also recognized some human qualities. He decided he had found a human ancestor that was so ancient it was still ape-like in many ways. (Later, scientists would determine the bones were nearly three million years old). Dart named the hominid Australopithecus africanus. The Taung Child, known by the name of the place where the fossils came from, was the first australopithecine ever discovered—and the first early hominid found in Africa. After the discovery, anthropologists who were searching for humanity’s origins in Europe and Asia switched their attention to Africa.
Mrs. Ples: Throughout the 1930s and 1940s, paleontologist Robert Broom led the efforts to find hominids in South Africa. He scoured the region’s limestone caves and quarries—the Taung Child came from a quarry—and was well rewarded for his efforts. Of the numerous fossils he uncovered (sometimes with the help of dynamite), his most influential find was a roughly 2.5-million-year-old skull of an adult female hominid now known as Mrs. Ples. Unearthed in 1947 at a site called Sterkfontein, the skull was well preserved and displayed the same mix of ape and human features seen in the Taung Child. Finding an adult version of A. africanus helped convince skeptics that the species was an ancient human ancestor. Some anatomists had thought Taung was just an ape and would have developed more pronounced ape-like features, and lost its human-like traits, as it grew up. Instead, Mrs. Ples showed that the species retained its mix of human and ape traits throughout life.
STS 14: Another one of Broom’s key finds is a set of well-preserved post-cranial bones that includes a pelvis, partial spine, ribs and upper thigh. Like Mrs. Ples, these fossils were found in 1947 at Sterkfontein and date to about 2.5 million years ago. The bones are officially known as STS 14 (STS refers to Sterkfontein) and presumably belonged to an A. africanus individual. The shape of the pelvis and spine are remarkably modern, and the find was some of the first evidence that early human ancestors walked upright on two legs.
SK 48: In addition to finding a trove of A. africanus specimens, Broom, along with his many assistants, discovered a new hominid species: Paranthropus robustus. The first hints of the species came in 1938 when Broom acquired a jaw fragment and molar that were much larger and thicker than any fossils belonging to A. africanus. Broom collected more of the unusual fossils and then hit the jackpot in 1950. A quarry worker found a nearly complete skull of an adult hominid that had giant teeth and a flat face. The fossil is officially called SK 48 (SK refers to the cave of Swartkrans where the skull was found). The collection of fossils with big chompers, which the hominids used to chew tough foods, was given the name P. robustus, which lived in South Africa about 1.8 million to 1.2 million years ago.
Little Foot: In the early 1990s, anthropologist Ron Clarke of South Africa’s University of the Witwatersrand found four small australopithecine foot bones at Sterkfontein. Later, Clarke and his colleagues discovered a nearly complete skeleton embedded in limestone that belonged to the foot. The researchers are still carefully chipping away at the rock to release the skeleton, dubbed Little Foot, but they have already noted that the individual has some characteristics not seen in any other known species of Australopithecus. But since the bones haven’t been fully studied and shared with other scientists, it’s hard to know where the hominid sits in the family tree, Science reported last year. It’s also hard to know exactly how old it is. Clarke’s team places the fossils at 3.3 million years old while other groups using different dating methods say Little Foot is more like 2.2 million years old. Science reported that Little Foot was expected to be fully liberated from its rocky enclosure sometime this year. As far as I know, that hasn’t happened yet.
Australopithecus sediba: The most recent major hominid fossil discovery in South Africa occurred in 2010. Lee Berger of the University of the Witwatersrand led a team that found two partial hominid skeletons at Malapa Cave. Dating to nearly two million years ago, the skeletons indicate that these hominids had their own unique style of walking and spent time both on the ground and in trees. X-ray scans of one of the skulls reveals that some aspects of the brain were more modern than in previous species. Berger and his colleagues therefore think the species, which they named A. sediba, could have given rise to the genus Homo.
Origins of Modern Behavior: Fossils aren’t the only major human evolution discoveries from South Africa. Several coastal cave sites have been treasure troves of artifacts that reveal when and how sophisticated behavior and culture emerged in early populations of Homo sapiens. There have been too many of these discoveries to single any one out. Some of these finds—such as red pigments used 164,000 years ago and shell beads dating to 77,000 years ago—are among the earliest evidence for symbolic thinking in our ancestors. Other artifacts, like 71,000-year-old projectile weapons, indicate early humans could construct complicated, multipart tools that require a lot of planning and foresight to make.
I love South African palaeoanthropology. I want to go to there.