Brunetto Chiarelli

Evidence for a genetic discontinuity between Neandertals and 24,000-year-old anatomically modern Europeans.

During the late Pleistocene, early anatomically modern humans coexisted in Europe with the anatomically archaic Neandertals for some thousand years. Under the recent variants of the multiregional model of human evolution, modern and archaic forms were different but related populations within a single evolving species, and both have contributed to the gene pool of current humans. Conversely, the Out-of-Africa model considers the transition between Neandertals and anatomically modern humans as the result of a demographic replacement, and hence it predicts a genetic discontinuity between them. Following the most stringent current standards for validation of ancient DNA sequences, we typed the mtDNA hypervariable region I of two anatomically modern Homo sapiens sapiens individuals of the Cro-Magnon type dated at about 23 and 25 thousand years ago. Here we show that the mtDNAs of these individuals fall well within the range of variation of todays humans, but differ sharply from the available sequences of the chronologically closer Neandertals. This discontinuity is difficult to reconcile with the hypothesis that both Neandertals and early anatomically modern humans contributed to the current European gene pool.

Phylogeny of the Hominoidea: The chromosome evidence

In the ten years since chromosome banding techniques were first applied to clarify the phylogenetic relationships of the Hominoidea a considerable amount of diverse and conflicting information has accumulated. Although human chromosomes can now be confidently derived from their ape counterparts, there is no general agreement on the exact phylogenetic sequence of species divergence. Some of this confusion derives from the practice of considering solely rearrangements of euchromatin, and making the assumption that all individuals of the same species have the same chromosomes. When the range of polymorphic chromosomes within species is included in the analysis more economical phylogenetic schemes can be developed. Common, derived karyological features may indicate that the Gorilla and Pan share a period of common descent after the divergence of Homo .

Comparative Morphometric Analysis of Primate Chromosomes I. The Chromosomes of Anthropoid Apes and of Man

SUMMARYIn a research programme on the karyological aspects of evolution in Primates the author in the present paper shows the results of a morphometric comparative analysis between the chromosomes of Man and the Anthropoid Apes.The chromosome number in the three genera of Apes (Gorilla, Pan and Pongo) in the somatic mitosis is always 48.The average lengths in μ of the karyotypes analysed in detail are as follows:Homo 93,7 ±19,3Pan 94,1 ± 9,1Pongo 83,6 ±11,4The comparative study of each single chromosome showed the similarity in dimension and morphology among some chromosomes of the various species.The sex chromosomes were studied from a comparative point of view. The Y chromosome is, in every case, one of the smallest of the set. While in Man, Chimpanzee and Gorilla it appears to be eucromatic along its entire length, in Orang-utan it has a big achromatic portion in its small arm. The position of the centromere is submetacentric in Pan, Homo and Pongo.The X cromosome seems to be one of the largest of the ...

Comparative Morphometric Analysis of Primate Chromosomes. III. The Chromosomes of the Genera Hylobates. Colobus and Presbytis

SUMMARYProceding with the morphometric analysis of the Primate chromosomes, in this paper the chromosomes of the genera Hylobates, Presbytis and Colobus are examined. All the species studied have a diploid number of chromosomes of 2n = 44.The comparison of the total lengths of the karyotypes has not shown any significant differences among these genera. The comparative morphometric analysis of each single chromosomes has shown some similarities among the chromosomes of the different genera.

Comparative Morphometric Analysis of Primate Chromosomes. II. The Chromosomes of the Genera Macaca, Papio, Theropithecus and Cercocebus

SUMMARYThe chromosomes of nearly all species of Monkeys belonging to the gener Macaca, Papio, Theropithecus and Cercocebus have been studied from a comparative morphometric point of View. All the species of these genera have a diploid number of chromosomes of 2n=42.Some differences in the chromosomes size and morphology of the different species have been found. They should be explained with inversion and translocation mechanisms.The comparative studies of the chromosomes in the different genera have revealed that the karyotype of Macaca, and Papio, Papio and Theropithecus are more similar that those of Cercocebus and Theropithecus.

Volatile Signals During Pregnancy: A Possible Chemical Basis for Mother–Infant Recognition

Human pheromones play a role in regulating relationships and apparently influence partner choice and mother–infant recognition. We analyzed the chemical content of volatiles from sweat patch samples from the para-axillary and nipple–areola regions of women during pregnancy and after childbirth. Solid phase microextraction was used to extract the volatile compounds, which were then characterized and quantified by gas chromatography–mass spectrometry. During pregnancy, women developed a distinctive pattern of five volatile compounds common to the para-axillary and nipple–areola regions (1-dodecanol, 1-1′-oxybis octane, isocurcumenol, α-hexyl-cinnamic aldehyde, and isopropyl myristate). These compounds were absent outside pregnancy and had slightly different patterns in samples from the two body areas. Differentiation of the volatile patterns among pregnant women may help newborns to distinguish their own mothers.

Mode and tempo in primate chromosome evolution: Implications for hylobatid phylogeny

The existence of a notable Hylobates moloch x Symphalangus syndactylus hybrid allows a more precise comparison of chromosomes found in these two karyologically diverse “lesser apes”. Between these two species no identical chromosomes are found and even the X-chromosomes differ. The haploid set of the siamang is about 20% longer than the gibbons. Thus, duplication and/or diletions have probably been an important mechanism of chromosome change, but inversions and translocations also appear to have been involved in transforming the karyotype. The gibbon karyotype is then compared with humans and macaque chromosomes. Some tentative homologies of chromosome parts are suggested, but only about 5–10% of the chromosomes complements appear to be homologous by banding. On the other hand, the human and macaque karyotypes share many similarities and sometimes apparently identical chromosomes. It is hypothesized that given the very different karyotypes found between H. moloch and S. syndactylus, rapid chromosome evolution has probably occurred in the Hylobatidae, while macaques and humans are karyogically more conservative. A standardization of the H. moloch karyotype is also proposed.

Chromosomes of thecercopithecus aethiops species group:C. aethiops (Linnaeus, 1758),C. cynosurus (Scopoli, 1786),C. pygerythrus (Cuvier, 1821), andC. sabaeus (Linnaeus, 1766)

The banded karyotypes of 34 monkeys of known geographic origin and belonging to the Cercopithecus aethiops group of species (C. aethiops, C. pygerythrus, C. cynosurus, C. sabaeus) show that chromosome evolution in this group is highly conservative. All species have 2n =60 chromosomes with very similar chromosome banding. However, differences were found both within and between species. A polymorphism of the NOR area of the “marked” chromosome pairs was found in all taxa (9 of 34 animals). All individuals referred to C. sabaeus,from both West Africa and the Barbados, are characterized by having highly positive G- and C- banded terminal sequences on chromosomes 7,10,12, and 14. Outgroup comparisons with other primates and a parsimony analysis suggest that these terminal bands are derived and are probably good taxonomic and phylogenetic indicators. Moreover, chromosome 18 is variable both between and within species in G banding and in short-arm length. The existence of within-species variation in karyotypes suggests that karyological comparisons must be based on adequate samples that include specimens coming from all the major geographic populations of the species concerned.

Ancient DNA Analysis of the Delta F508 Mutation

When working with highly degraded DNA, validating the results of a slightly polymorphic system always complicates the analysis because of the difficulties in recognizing contamination and artifacts. Recognition can be greatly simplified by employing a multiplex reaction that coamplifies the fragments together with several highly polymorphic markers, for instance, short tandem repeats. In this work, we successfully included newly designed oligonucleotide primers for the detection of delta F508, the most frequent mutation causing cystic fibrosis, in the commercial AmpFlSTR Profiler Plus™ PCR Amplification Kit (PE Applied Biosystems). This coamplification enabled us to test the hypothesis of a heterozygote advantage associated with cystic fibrosis—specifically, higher resistance to toxin-mediated diarrheas—in a Sicilian skeletal sample of individuals who died in a cholera epidemic in 1837. The proposed method should also be suitable for the genetic characterization of other slightly polymorphic loci tested on human and animal ancient DNA; it should permit simple authentication of results by comparing the fingerprints obtained from independent amplifications repeated several times.

RAPD (Random Amplified Polymorphic DNA) fingerprinting analysis of some Italian populations of fallow deer Dama dama

Abstract The present paper deals with the genetic relationships between the two oldest Italian fallow deer populations (Castelporziano and San Rossore) in order to investigate their origin, and to verify their status and variability in the light of the genetic consequences of human selection through historical times. The analysis, performed using the RAPD fingerprinting technique, confirms the low variability of the San Rossore fallow deer, and reveals the Castelporziano population characterised by an unexpected higher rate of variability.