Ancient Siberian finger leads to new possible human lineage

The scientist has found that the DNA from ancient Siberian finger did not match any of modern human DNA or a Neadratal.  To be more specific this is the mitochondrial DNA (mtDNA). When ancient-DNA expert Svante Pääbo gave his colleague Johannes Krause a sample of a 40,000-year-old human finger bone from a Siberian cave, he had only one question: Was its mitochondrial DNA (mtDNA) that of

a Neandertal or a modern human?

It was neither. Evolutionary geneticists Pääbo and Krause, of the Max Planck Institutefor Evolutionary Anthropology in Leipzig, Germany, have apparently identified a new lineage of ancient human, the first time that this has been done using ancient DNA and not fossil bones.

“I couldn’t believe it,” Pääbo says. “I thought Johannes was pulling my leg.” The

complete sequence of mtDNA from the finger bone, reported online this week in Nature, suggests that Central Asia was occupied at that time not only by Neandertals and Homo sapiens but also by a third, previously

unknown hominin lineage. “This is the most exciting discovery to come from the ancient DNA field so far,” says Chris Tyler-Smith, a geneticist at the Sanger Institute in Hinxton, United Kingdom. “A stunning piece of

work,” says Terence Brown of the University of Manchester in the U.K.

The work complicates the human story, much as the discovery of the controversial H. floresiensis—a.k.a. the hobbit—has upset earlier and simpler views of early human migrations around the globe. If four hominins including the hobbit were alive about 40,000 years ago, “the amount of human biodiversity … was pretty remarkable,” says geneticist Sarah Tishkoff of the University of Pennsylvania. For now, Pääbo’s

team is not naming the new lineage.

Hobbit from Indonesia- human evolution need revision

In 2004 a team of Australian and Indonesian scientists who had been excavating a cave called Liang Bua on the Indonesian island of Flores announced that they had unearthed something extraordinary: a partial skeleton of an adult human female who would have stood just over a meter tall and who had a brain a third as large as our own. The specimen, known to scientists as LB1, quickly received a fanciful nickname—the hobbit,like a race in Lord of the Ring. The team proposed that LB1 and the other fragmentary remains they recovered represent a previously unknown human species, Homo floresiensis. Their best guess was that H. floresiensis was a descendant of H. erectus—the first species known to have colonized outside of Africa. The creature evolved its small size, they surmised, as a response to the limited resources available on its island home—a phenomenon that had previously been documented in other mammals, but never humans.


Scientists initially postulated that H. floresiensis descended from H. erectus, a human ancestor with body proportions similar to our own.New investigations show that the hobbits were more primitive than researchers thought, however—a finding that could overturn key assumptions about human evolution.

The new construction of coral family tree and shows the ocean's evolutionary potential

The deep sea may not seem like a crucible of evolution. For me, according to Darwin, evolution is correlate to natural selection. Compare with the organism living in land and shallow seas, they may have more competition to survive especially when human take control in the world — cause many pollution and destruction. So evolution rates are increase in the name of survival.


But, to the surprise of biologists, a new construction of the coral family tree suggests that evolution proceeds at full bore in waters well below where sunlight penetrates. Moreover, some coral diversity may have bloomed there first, before spreading coastward—the reverse of what has long been thought. “As people look in the deep sea, they are finding much more diversity than they expected,” says Clifford Cunningham, an evolutionary biologist at Duke University in Durham, North Carolina. “We’re just at the very beginning of understanding deep-sea evolution.”

Besides that, the evolution potential not only seem in coral, but in other deep sea organism too. Marymegan Daly, a systematist at Ohio State University, Columbus, and co-coordinator of the Cnidarian Tree of Life project, has found a similar pattern among the sea anemones she’s analyzed. “We see lots of radiations of deep-deep sea forms,” she reported. In short, concludes France, “we can’t say that the deep sea is a boring
environment in terms of evolution.”

I think this are the beginning of the new saga in evolutionary study to understand the evolution pattern in deep sea.

Debates about how eukaryotes get the mitochondria.

 I would like to share with you the debates about eukaryotic evolution. The evolution of eukaryotes is something very hard to understand the process of evolution. One of them that always debate, how they acquired the membranebound organelle, mitochondria. Mitochondria produce energy in nearly all eukaryotic cells and regulate cell metabolism by controlling the flow of factors such as ions, amino acids, and carbohydrates between themselves and the cytoplasm. Mitochondria evolved from a bacterial endosymbiont (an α-proteobacterium), and this process depended on the establishment of new pathways that facilitated the import of proteins into and across the double membrane (inner and outer) of the ancestral endosymbiont. Herein lies a debate: How did the process of protein import in mitochondria—which facilitated the evolution of this organelle, and thus, eukaryotic cell evolution— arise? Was the process driven by the ancestral host cell or by the prokaryotic endosymbiont, or by both?


Recently, Gross and Bhattacharya discussed the possibility that evolution of protein import into mitochondria was driven by the host cell (see the fi gure).In this paradigm, to capitalize on energy production by the ancestral endosymbiont, a protein sorting and importing mechanism was necessary to relocate host cell proteins to the endosymbiont. Thus, in the earliest evolutionary stages of mitochondria, host proteins were “imposed” on the ancestral endosymbiont.


It was argued that because the endosymbiont’s outer membrane had greatest access to host factors in the cytoplasm, evolution of mitochondrial protein import began at the outer membrane. Once established there, host proteins could then gain access to the intermembrane space and the inner membrane in an “outsideto- inside” trajectory of evolution.

Two views of mitochondrial evolution. The “Inside” view of the transition from intracellular bacterium to mitochondrion acknowledges that the ancestral endosymbiont’s genome encoded protein complexes (SecYEG and YidC) that facilitated the assembly of bacterial proteins into its inner membrane (e.g., metabolite carriers) and outer membrane (the bacterial β-barrel protein BAM). An early outer-membrane protein of the TOM complex (Tom40) may have arisen from a bacterial β-barrel protein with affinity for basic, amphipathic amino acid sequences on host cell proteins. Progenitors of modern protein import components (TIM) were also encoded by the endosymbiont’s genome. The “Outside” view proposes that proteins of the ancestral host cell were imported into the endosymbiont. It assumes that the endosymbiont’s genome is reduced (and unable to encode progenitor proteins of the import machinery). In this case, some host cell β-barrel protein is imposed into the endosymbiont’s outer membrane. It then facilitates the import of other protein import machinery components from the host cell.

To read further please refer this article on Science Magazine 5 february 2010 titled "Tinkering Inside the Organelle".