A small and very old lady from Flores provides human evolutionary biologists with a dilemma

In late 2004, the unearthing of an 18,000-year-old skeleton at Liang Bua on the Eastern Indonesian island of Flores has presented a significant paradox |

for evolutionary biologists to ponder si, S2. The discovery of tiny, 1-m-tall hominins, nicknamed "hobbits" by their discoverers, but more correctly termed Homo floriensis brought to the worlds attention a species with a brain roughly one third the size of that of modern man's. However, despite such a small brain, it seems that this new species of hominin had very large | temporal lobes, a character normally associated with auditory and speech recognition. Furthermore, Homo floriensis had substantial convolutions of the I frontal lobes indicating an ability for higher cognition. So, despite a small brain, | these diminutive hominins may have been capable of shaping and using stone tools, a characteristic normally reserved for prehistoric modern man, rather than earlier hominins S3.

The important finding here is that Homo floriensis may defy our long-held beliefs relating to the evolution of the human brain. Specifically, advanced behavioral traits and the creation and use of stone implements do not require an anatomically modern brain—the same outcome may be achieved | simply by rewiring and increasing the convolutions of a smaller brain. Little comparability was found between endocasts derived from Homo floriensis and those of the modern human pygmy and abnormal microcephalic brains, | and so the anatomical structure of the Homo floriensis brain challenges accepted wisdom on the importance of brain size.

The second interesting deduction is that the tiny stature of Homo floriensis suggests humans are as readily influenced by evolutionary forces as are any other species: The genetic isolation of Homo floriensis on Flores led to selection pressures shrinking this hominin to dwarf proportions due to the limited resources on this Indonesian island. Clearly, as a genus, Homo is far|| more adaptive in terms of its morphological response to ecological determinants, such as food availability, than we had previously thought possible.

The recent discovery of Homo floriensis along with many other new taxa raises a third point: The origin, number, antiquity, and morphological characteristics of several recent discoveries relating to the fossil hominin record have led to a call for an alternative viewpoint on paleoanthropology's fundamental "out of Africa" paradigm S4. It certainly seems that our recent evolution is neither clear cut nor is it fully understood.

Specific references to this subject:

51. Brown P, Sutikna T, Morwood MJ. et al A new small-bodied hominin from the Late Pleistocene of Flores, Indonesia. Nature 2004; 431: 1043-4.

52. Morwood MJ, Soejono RP, Roberts RG, et al Archaeology and age of a new hominin from Flores in eastern Indonesia. Nature 2004; 431: 1087-91.

53. Baiter M. Paleoanthropology. Small but smart? Flores hominid shows signs of advanced brain. Science 2005; 307:1386-9.

54. Dennell R, & Roebroeks W. An Asian perspective on early human dispersal from Africa. Nature 2005; 438:1099-104.

Figure 1.8. The 2004 discovery of Homo floriensis on the Indonesian island of Flores challenges our perceived wisdom relating to man's recent evolutionary past.

A simple representation of an interactome

Figure 1.9. An extremely simple rendering of the interactome; unfortunately, reality is infinitely more complex than can be represented here. Imagine each node as a cluster of proteins with similar cellular function. Each cluster is then linked by an interactive network. As an example, three juxtaposed nodes in the above figure might represent DNA synthesis proteins, DNA repair proteins, and cell-cycle regulatory proteins. Then consider a hypothetical node for proteins involved in protein folding; these are likely to be located at a more distant nexus as they are not closely involved with the former three protein clusters. Now imagine how complex an interactome for humans would be if each protein represented a single node!

Figure 1.9. An extremely simple rendering of the interactome; unfortunately, reality is infinitely more complex than can be represented here. Imagine each node as a cluster of proteins with similar cellular function. Each cluster is then linked by an interactive network. As an example, three juxtaposed nodes in the above figure might represent DNA synthesis proteins, DNA repair proteins, and cell-cycle regulatory proteins. Then consider a hypothetical node for proteins involved in protein folding; these are likely to be located at a more distant nexus as they are not closely involved with the former three protein clusters. Now imagine how complex an interactome for humans would be if each protein represented a single node!

nutritional pharmacology in the context of genetic polymorphisms and clinical experience." These are sound definitions, and worthy of reiteration for all students of the subject.

As our knowledge of the "nutriome" improves and the gaps within the interactome are filled in, it seems likely that the buzzwords of today like nutrigenomics and nutritional genetics will ultimately give way to the unifying field of human molecular nutrition.

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