Portal vein serum anti-flagellin antibody was assessed by ELISA. Hepatobiliary transporter mRNA expression in the liver was measured by RT-PCR. Results: Creation of a SFBL induced a dramatic increase in intraluminal bacterial counts compared to sham mice. 100% of SFBL mice had mesenteric lymph node translocation, compared to 9% of sham mice. SFBL mice had significantly higher histological scores for intrahepatic cholangitis and hepatocellular injury, as well as for jejunal barrier disruption parameters, consistent with ongoing learn more injury. Creation of SFBL resulted in decrease in bile flow rate, but increase in total biliary bile acid concentration. Significant reductions in

bile phospholipid and cholesterol output, but not bile acid output were observed in the SFBL group, which resulted in a significant elevation in bile acid/phospholipid ratio, suggestive of the formation of toxic bile. Portal vein serum bile composition exhibited no difference between SFBL and sham

mice. A significant reduction in hepatic expression of hepatobiliary transporters involved in biliary canalicular export (Abcg8, Bsep, Mrp2 and Mdr2), as well as basolateral uptake (Ntcp, Oatp1, Oatp2 and Oatp4), was observed in SFBL mice. Conclusion: Taken together, the above data suggest that small bowel bacterial BMS-907351 in vivo overgrowth alters bile composition with formation of toxic bile via changes in the expression of hepatobiliary transporters, which may play a potential pathogenic role in liver inflammation and cholestatic injury. Disclosures: The following people have nothing to disclose: Qingqing Wang, Vijay Saxena, Bin Wang, Lili Miles, Jaimie D. Nathan Objective: We tested the hypothesis that a common genetic variant in Niemann-Pick C1-Like protein 1(NPC1L1) is associated with check details decreased risk of ischemic vascular disease and with increased

risk of symptomatic gallstone disease. Background: NPC1L1 mediates cholesterol uptake from the intestine and bile into enterocytes and hepatocytes, respectively. An NPCIL1 genetic variant mimicking the effect of ezetimibe, an inhibitor of N PC 1L1, s associated with reduced low-density l ipoprotein(LDL) cholesterol and possibly with increased biliary cholesterol, a risk factor for gallstone disease. Methods: We genotyped 73, 457 individuals from the Danish general population, including 10, 481 with ischemic vascular disease and 3, 874 with symptomatic gallstone disease, for NPC1L1 rs2072183.Results: NPC1L1 genotype was associated with stepwise reductions in plasma levels of LDL cholesterol of up to 1.6%(0.05 mmol/L) for CC versus GG-homozygotes(Ptrend<0.001). Multifactorially adjusted hazard ratios(HRs) for ischemic vascular disease were 0.95(95% confidence interval, 0.87-1.03) for CG-heterozygotes and 0.93(0.86-1.01) for CChomozygotes versus GG-homozygotes(P-trend=0.07).

Portal vein serum anti-flagellin antibody was assessed by ELISA. Hepatobiliary transporter mRNA expression in the liver was measured by RT-PCR. Results: Creation of a SFBL induced a dramatic increase in intraluminal bacterial counts compared to sham mice. 100% of SFBL mice had mesenteric lymph node translocation, compared to 9% of sham mice. SFBL mice had significantly higher histological scores for intrahepatic cholangitis and hepatocellular injury, as well as for jejunal barrier disruption parameters, consistent with ongoing Ulixertinib cost injury. Creation of SFBL resulted in decrease in bile flow rate, but increase in total biliary bile acid concentration. Significant reductions in

bile phospholipid and cholesterol output, but not bile acid output were observed in the SFBL group, which resulted in a significant elevation in bile acid/phospholipid ratio, suggestive of the formation of toxic bile. Portal vein serum bile composition exhibited no difference between SFBL and sham

mice. A significant reduction in hepatic expression of hepatobiliary transporters involved in biliary canalicular export (Abcg8, Bsep, Mrp2 and Mdr2), as well as basolateral uptake (Ntcp, Oatp1, Oatp2 and Oatp4), was observed in SFBL mice. Conclusion: Taken together, the above data suggest that small bowel bacterial NVP-AUY922 overgrowth alters bile composition with formation of toxic bile via changes in the expression of hepatobiliary transporters, which may play a potential pathogenic role in liver inflammation and cholestatic injury. Disclosures: The following people have nothing to disclose: Qingqing Wang, Vijay Saxena, Bin Wang, Lili Miles, Jaimie D. Nathan Objective: We tested the hypothesis that a common genetic variant in Niemann-Pick C1-Like protein 1(NPC1L1) is associated with selleck kinase inhibitor decreased risk of ischemic vascular disease and with increased

risk of symptomatic gallstone disease. Background: NPC1L1 mediates cholesterol uptake from the intestine and bile into enterocytes and hepatocytes, respectively. An NPCIL1 genetic variant mimicking the effect of ezetimibe, an inhibitor of N PC 1L1, s associated with reduced low-density l ipoprotein(LDL) cholesterol and possibly with increased biliary cholesterol, a risk factor for gallstone disease. Methods: We genotyped 73, 457 individuals from the Danish general population, including 10, 481 with ischemic vascular disease and 3, 874 with symptomatic gallstone disease, for NPC1L1 rs2072183.Results: NPC1L1 genotype was associated with stepwise reductions in plasma levels of LDL cholesterol of up to 1.6%(0.05 mmol/L) for CC versus GG-homozygotes(Ptrend<0.001). Multifactorially adjusted hazard ratios(HRs) for ischemic vascular disease were 0.95(95% confidence interval, 0.87-1.03) for CG-heterozygotes and 0.93(0.86-1.01) for CChomozygotes versus GG-homozygotes(P-trend=0.07).

6% (267/395) in the HCV group (P < 0.001). The malignancies in the NAFLD group were observed in the following order: gastric cancer 34 cases (20.4%) > colon cancer 31 cases (18.6%) > prostate cancer 21 cases (12.6%). Conclusions:  The incident

rates of hepatocellular carcinoma in all the malignancies were approximately 6% in the NAFLD group and two-thirds in the HCV group. “
“Liver http://www.selleckchem.com/products/mi-503.html cirrhosis (LC) is accompanied by hepatic arterializations, intrahepatic shunts, and hyperdynamic circulations. These changes shorten the arrival time (AT) of ultrasound contrast agents to the hepatic vein (HV). Whether treatment of gastric fundal varices (GVs) by balloon-occluded transvenous obliteration (B-RTO) improves the AT in LC patients was prospectively investigated. A total of 32 LC patients with GVs and 10 normal

controls (NCs) were enrolled. This study was approved by the clinical research ethics committee. Images of hepatic artery (HA), portal vein (PV), and HV were monitored after an GSK-3 phosphorylation injection of a contrast agent using quantification software. The AT before and after B-RTO in LC patients and that in NCs were compared. All GVs were treated effectively, and indocyanine green retention rate was improved (P < 0.0001). The mean values of the HA, PV, and HV ATs in the NCs were 21.9 ± 3.3, 28.2 ± 2.0, and 40.5 ± 2.1 s, respectively. Those in LC patients were 17.4 ± 4.4, 21.9 ± 5.6, and 26.3 ± 6.7, respectively, which were shorter than those in NCs (P < 0.01, P < 0.002, P < 0.0001,

respectively). However, these ATs were significantly learn more prolonged 1 week after B-RTO, with mean values of 18.7 ± 4.8, 23.8 ± 6.0, and 30.0 ± 7.2 s (P = 0.043, P < 0.01, P < 0.001). Obliteration of GVs shifted the AT in LC patients to the normalization, raising the possibility of improvement of arterialization and intrahepatic shunt. "
“Division of Gene Therapy and Hepatology, Center for Applied Medical Research, University of Navarra, Pamplona, Spain Obesity-induced insulin resistance is associated with both ectopic lipid deposition and chronic, low-grade adipose tissue inflammation. Despite their excess fat, obese individuals show lower fatty-acid oxidation (FAO) rates. This has raised the question of whether burning off the excess fat could improve the obese metabolic phenotype. Here we used human-safe nonimmunoreactive adeno-associated viruses (AAV) to mediate long-term hepatic gene transfer of carnitine palmitoyltransferase 1A (CPT1A), the key enzyme in fatty-acid β-oxidation, or its permanently active mutant form CPT1AM, to high-fat diet-treated and genetically obese mice. High-fat diet CPT1A- and, to a greater extent, CPT1AM-expressing mice showed an enhanced hepatic FAO which resulted in increased production of CO2, adenosine triphosphate, and ketone bodies.

6% (267/395) in the HCV group (P < 0.001). The malignancies in the NAFLD group were observed in the following order: gastric cancer 34 cases (20.4%) > colon cancer 31 cases (18.6%) > prostate cancer 21 cases (12.6%). Conclusions:  The incident

rates of hepatocellular carcinoma in all the malignancies were approximately 6% in the NAFLD group and two-thirds in the HCV group. “
“Liver GSK2126458 ic50 cirrhosis (LC) is accompanied by hepatic arterializations, intrahepatic shunts, and hyperdynamic circulations. These changes shorten the arrival time (AT) of ultrasound contrast agents to the hepatic vein (HV). Whether treatment of gastric fundal varices (GVs) by balloon-occluded transvenous obliteration (B-RTO) improves the AT in LC patients was prospectively investigated. A total of 32 LC patients with GVs and 10 normal

controls (NCs) were enrolled. This study was approved by the clinical research ethics committee. Images of hepatic artery (HA), portal vein (PV), and HV were monitored after an Dabrafenib mouse injection of a contrast agent using quantification software. The AT before and after B-RTO in LC patients and that in NCs were compared. All GVs were treated effectively, and indocyanine green retention rate was improved (P < 0.0001). The mean values of the HA, PV, and HV ATs in the NCs were 21.9 ± 3.3, 28.2 ± 2.0, and 40.5 ± 2.1 s, respectively. Those in LC patients were 17.4 ± 4.4, 21.9 ± 5.6, and 26.3 ± 6.7, respectively, which were shorter than those in NCs (P < 0.01, P < 0.002, P < 0.0001,

respectively). However, these ATs were significantly find more prolonged 1 week after B-RTO, with mean values of 18.7 ± 4.8, 23.8 ± 6.0, and 30.0 ± 7.2 s (P = 0.043, P < 0.01, P < 0.001). Obliteration of GVs shifted the AT in LC patients to the normalization, raising the possibility of improvement of arterialization and intrahepatic shunt. "
“Division of Gene Therapy and Hepatology, Center for Applied Medical Research, University of Navarra, Pamplona, Spain Obesity-induced insulin resistance is associated with both ectopic lipid deposition and chronic, low-grade adipose tissue inflammation. Despite their excess fat, obese individuals show lower fatty-acid oxidation (FAO) rates. This has raised the question of whether burning off the excess fat could improve the obese metabolic phenotype. Here we used human-safe nonimmunoreactive adeno-associated viruses (AAV) to mediate long-term hepatic gene transfer of carnitine palmitoyltransferase 1A (CPT1A), the key enzyme in fatty-acid β-oxidation, or its permanently active mutant form CPT1AM, to high-fat diet-treated and genetically obese mice. High-fat diet CPT1A- and, to a greater extent, CPT1AM-expressing mice showed an enhanced hepatic FAO which resulted in increased production of CO2, adenosine triphosphate, and ketone bodies.

To detect IRS pY and IRS/PI3K APO866 molecular weight association, liver extracts were subjected to immunoprecipitation with IRS-1 or IRS-2 antibody prior to immunoblotting. Serum hCRP was determined using an enzyme-linked immunosorbent assay (ELISA) kit (Helica, Fullerton, CA), with no crossreactivity with rat CRP. Blood glucose was determined with an Abbott FreeStyle glucometer. [3H]-glucose-specific activity was measured in the supernatants of Ba(OH)2 and Zn2SO4 precipitates of plasma samples

after they were evaporated to dryness to eliminate tritiated water. Plasma insulin was determined using a radioimmunoassay kit (Millipore, Bedford, MA), and FFA measured using an enzymatic assay kit (Wako, Osaka, Japan). Plasma TNF-α and adiponectin were quantified using rat ELISA kits from Invitrogen and Millipore, respectively. IL-6 and leptin were determined using the Luminex technique and a rat MAP multiplex kit (Millipore). Primary rat hepatocytes were isolated by liver perfusion as described,22 with some modifications. Briefly, under 4% isoflurane-induced general anesthesia, livers were isolated from the circulatory system;

the thoracic aorta, the caudal vena cava, the abdominal aorta, and the abdominal vena cava were tied off. The portal vein was severed, and livers were perfused by way of the inferior vena cava with perfusion medium followed by digest medium at 42°C. The liver was excised and minced in wash medium. Digested tissue was filtered through a cell strainer (100 μm), and hepatocytes Rucaparib molecular weight were pelleted by centrifugation, washed, and resuspended in Williams E medium containing 5% fetal bovine serum (FBS), 0.0015 μg/mL insulin, and 0.1% penicillin-streptomycin. Cells were seeded on cell culture plates and incubated for 3 hours (37°C, 5% CO2). Following an overnight serum-free incubation, selleck products cells were incubated with U0126 (100 μmol/L) or SB203580 (50 μmol/L). Thirty minutes later, hCRP (30 mg/L) or vehicle was added for 150 minutes. The

hCRP concentration and incubation period were designed to match those in the in vivo study as described above. To determine the time- and concentration-dependency of the effect of hCRP on insulin signaling in vitro, we performed additional studies in which hCRP at 15 mg/L and 30 mg/L, respectively, was incubated with cells for 75 minutes and 150 minutes, respectively. For detection of insulin-stimulated IRS-1/PI3K association and pY, 100 nM human insulin or saline was added for 10 minutes. No insulin was added for measurements of MAPKs and IRS-1 serine phosphorylation. Cell lysates were prepared and subjected to immunoprecipitation and/or immunoblotting analyses. Data were presented as mean ± SE. Comparisons among groups were made using Student’s t tests or repeated measures analysis of variance (ANOVA) followed by pairwise post-hoc analysis.

“
“The distribution of suitable rest sites is considered to be a key determinant of spatial patterns in animal activity. However, it is not immediately evident which landscape features satisfy rest site requirements or how these sites are configured within the www.selleckchem.com/products/ch5424802.html home range. We used Global Positioning System (GPS)/accelerometer telemetry to investigate rest site selection at the home-range scale for northern tamanduas Tamandua mexicana on Barro Colorado Island (BCI), Panama.

We developed models specifying each tamandua as the individual experimental unit and averaged coefficients to produce population-level estimates. Tamanduas had on average 17.8 (± 8.1) rest sites within their home range and used 1.36 (± 0.51) on any given day. These rest sites

tended to be located in the core of tamandua home ranges, with active locations associated with the periphery of the home range. Rest sites were positively associated with (1) a high density of Attalea butyracea palm trees; (2) elevation; (3) tall vegetation. There was a slight negative relationship between the distribution of rest sites and slope, and no apparent relationship between rest site selection and relative distance to forest canopy gaps. From focal animal observations, we identified that tamandua rest sites were typically located BAY 73-4506 price in trees (90%), with 25% (12 of 49) occurring in palms. We contend that northern tamanduas on BCI selected vegetated arboreal rest sites because of reduced likelihood of detection from terrestrial predators in these sites. Our

models identified considerable individual variation in rest site selection, which suggests that the practice of pooling individuals and fitting models at an aggregate level may be inappropriate for certain types of habitat selection research. “
“We use the term ‘aggressive mimic’ for selleck kinase inhibitor predators that communicate with their prey by making signals to indirectly manipulate prey behaviour. For understanding why the aggressive mimic’s signals work, it is important to appreciate that these signals interface with the prey’s perceptual system, and that the aggressive mimic can be envisaged as playing mind games with its prey. Examples of aggressive mimicry vary from instances in which specifying a model is straight forward to instances where a concise characterization of the model is difficult. However, the less straightforward examples of aggressive mimicry may be the more interesting examples in the context of animal cognition. In particular, there are spiders that prey on other spiders by entering their prey’s web and making signals. Web invasion brings about especially intimate contact with their prey’s perceptual system because the prey spider’s web is an important component of the prey spider’s sensory apparatus. For the web-invading spider, often there is also a large element of risk when practising aggressive mimicry because the intended prey is also a potential predator.

The purpose of this study is to investigate the characteristics of difficult cases of endoscopic papillary largediameter balloon

dilation. Methods: The patients with choledocholithiasis Napabucasin who had an incomplete extraction of bile duct stones in the first session between November 2009 and September 2013 were included in this study. After sphincterotomy large-diameter balloon dilation was performed. Bile duct stones were then removed with mechanical lithotripsy. Results: Twelve patients with choledocholithiasis who had a failed extraction by EPLBD in the first session were enrolled in the study. The success rate in the first session

was 87.5%. In five cases cholecystectomy was previously performed. Seven patients had a duodenal parapapillary diverticulum. One patient had a history of gastrectomy and open surgical clearance of common bile duct stones. Nine patients had been treated with endoscopic removal of bile duct stones previously. The number of mean endoscopic treatment session was 1.6. There were no significant differences in patients’ background between technically succeeded cases and failed cases. The cause of failure was as follows: in six cases poor bile duct expansion, in six cases stone impaction due to too many stones in the bile duct or too large stone for the basket catheter. Ten of twelve cases had experienced recurrent cholangitis check details after first treatment. In two cases, second attempt of endoscopic clearance of bile duct stones was succeeded. Conclusion: This study suggested that selleck chemicals llc the cases with poor

dilated intrapancreatic bile ducts, small diameter of the bile duct, too large stone and stone impaction due to too many stones in the bile duct require close attention. Key Word(s): 1. choledocholithiasis; 2. large balloon dilation Presenting Author: HISATOMO IKEHARA Additional Authors: TOSHIHIRO OKADA, KAZUHIRO SUZUMURA, SEIKAN HAI, TOSHIHIKO TOMITA, TADAYUKI OSHIMA, HIROKAZU FUKUI, JIRO WATARI, JIRO FUJIMOTO, HIROTO MIWA Corresponding Author: HISATOMO IKEHARA Affiliations: Hyogo College of Medicine, Hyogo College of Medicine, Hyogo College of Medicine, Hyogo College of Medicine, Hyogo College of Medicine, Hyogo College of Medicine, Hyogo College of Medicine, Hyogo College of Medicine, Hyogo College of Medicine Objective: Endoscopic submucosal dissection (ESD) is widely accepted as less invasive treatment for early gastric cancer. However, regarding duodenal neoplasms, high perforation rate of duodenal ESD has been reported. Duodenal perforation causes severe peritonitis in some cases.

152 The Hh signaling pathway plays a critical role in reducing apoptosis and inducing the expansion and proliferation of various progenitor populations.153,154 Consistent with these observations, Hh ligand expression increases in parallel with the degree of hepatocyte apoptotic activity152 leading to the expansion of liver progenitor cells and for these cells to undergo EMT.151 Hh ligands also activate HSCs, induce their proliferation and promote the transition of quiescent HSCs to matrix producing MF.155 Intriguingly, HSC-MF themselves are also capable of secreting LY2157299 manufacturer Hh ligands, suggesting that an autocrine feed-back loop may sustain Hh signaling and HSC-MF population. Treatment with cyclopamine

(a specific Hh pathway inhibitor) leads to MF apoptosis, reduced matrix deposition Selleck Romidepsin and attenuated fibrosis. Leptin, a highly conserved cytokine-like hormone secreted by adipose tissue and activated T cells, stimulates HSC activation perhaps through activating the Hh pathway via the PI3K and JAK-STAT signaling.155 During fibrosis, MFs accumulate

in close proximity with liver progenitor cells.156 Enhanced cellular proliferation and activation were observed in co-cultures of HSCs with liver progenitor cells compared with mono-cultures, and these effects were mediated by Hh ligands.157 Intriguingly, progenitor cells are also capable of producing Hh ligands. Because Hh ligands are critical for the survival of these cells, downregulation of Hh would normally lead to resolution of scarring once injury is removed. Consistent with these observations, wild type mice when fed the

methionine choline deficient diet and ethionine (E) supplemented diet and Patched-deficient mice (with dysregulated Hh signaling) on MCD, exhibit greater liver injury-related accumulation of liver progenitor cells, EMT, MF and fibrosis treatment, while inhibition of Hh activity results in a reversal of outcomes.151 Over-activation of the Hh pathway also occurs in progressive human ALD and NAFLD.149,151 Intriguingly, the number of Hh responsive progenitor cells is significantly greater in patients with more selleck chemical severe ASH (Discriminant function, DF > 32) and hepatocyte apoptosis, compared with those with less severe injury (DF < 32). A similar occurrence is observed in NAFLD, with greater Hh activity and EMT in individuals with advanced NASH-fibrosis compared with those with early stage disease. In steatohepatitis, the number of inflammatory cells infiltrating the liver increases significantly compared with simple steatosis.158 The number and type of inflammatory infiltrate predict disease progression to fibrosis and cirrhosis,159–161 and recruitment from the circulation is the critical step in the progression of chronic hepatitis. Hence, repair is intricately linked to inflammatory cell recruitment and disease outcome. Hh signaling activates the immune response.

07 ha±0.43) than Sirolimus concentration individuals living near roads (3.79 ha±0.22) and residential areas (3.40 ha±0.26). Similarly, home-range core areas (FK50%) were significantly larger in forest interiors (1.49±0.13 ha) than near road (0.78±0.07 ha) and residential edges (0.70±0.08 ha). We also found that squirrel gliders regularly cross narrow roads up to 20 m wide and with a tree gap up to 15 m to access adjacent vegetation, and are willing to utilize foraging resources in residential backyards. Changes

in squirrel glider home ranges near edges identified in this study have implications for understanding how this species responds to urban edges, and we highlight important areas for future edge-related studies to correctly inform conservation and management. “
“It has recently been argued that the elongate necks of sauropod dinosaurs evolved primarily through selection for their use as sexual and dominance signals, and not as an adaptation for accessing a large ‘feeding envelope’ as traditionally thought. Here we explore this idea and show that all six arguments that have been advanced in support of the sexual selection hypothesis are flawed: there is no evidence for sexual dimorphism in the necks of sauropods; neither is there any evidence that they were used in dominance displays; long necks provided significant survival benefits in allowing high browsing and energetically

efficient grazing; their fitness cost was likely less than has been assumed; their positive

allometry through ontogeny is uninformative given that ontogenetic allometry is common in animals; apparent lack of correlation between neck learn more and leg length across phylogeny is illusory due to over-representation of mamenchisaurids in a previously analysed dataset, and in any case is not informative find more as the unique morphology of sauropod necks suggests they, rather than legs, may have been cheaper to elongate when evolving increased vertical reach. In no speciose, morphologically varied, long-lived tetrapod clade has sexual selection consistently acted on a single part of the body, and it is unlikely that Sauropoda is the exception to this. In summary, there is no convincing evidence that sexual selection was the primary force driving the evolution of sauropod necks. While a subsidiary role for sexual selection cannot be discounted, the traditional hypothesis that sauropod necks evolved primarily due to the feeding benefits that they conferred is, by comparison, far better supported. “
“The contemporary distribution of organisms cannot be understood without knowing how species have responded to the geologic and climatic history of their environments. Genetic studies related to the demographic history of wildlife species can help us to elucidate the role of climate changes and other environmental forces in shaping patterns of distribution and population structure of the species.

07 ha±0.43) than AUY-922 cost individuals living near roads (3.79 ha±0.22) and residential areas (3.40 ha±0.26). Similarly, home-range core areas (FK50%) were significantly larger in forest interiors (1.49±0.13 ha) than near road (0.78±0.07 ha) and residential edges (0.70±0.08 ha). We also found that squirrel gliders regularly cross narrow roads up to 20 m wide and with a tree gap up to 15 m to access adjacent vegetation, and are willing to utilize foraging resources in residential backyards. Changes

in squirrel glider home ranges near edges identified in this study have implications for understanding how this species responds to urban edges, and we highlight important areas for future edge-related studies to correctly inform conservation and management. “
“It has recently been argued that the elongate necks of sauropod dinosaurs evolved primarily through selection for their use as sexual and dominance signals, and not as an adaptation for accessing a large ‘feeding envelope’ as traditionally thought. Here we explore this idea and show that all six arguments that have been advanced in support of the sexual selection hypothesis are flawed: there is no evidence for sexual dimorphism in the necks of sauropods; neither is there any evidence that they were used in dominance displays; long necks provided significant survival benefits in allowing high browsing and energetically

efficient grazing; their fitness cost was likely less than has been assumed; their positive

allometry through ontogeny is uninformative given that ontogenetic allometry is common in animals; apparent lack of correlation between neck KU-57788 in vivo and leg length across phylogeny is illusory due to over-representation of mamenchisaurids in a previously analysed dataset, and in any case is not informative selleck inhibitor as the unique morphology of sauropod necks suggests they, rather than legs, may have been cheaper to elongate when evolving increased vertical reach. In no speciose, morphologically varied, long-lived tetrapod clade has sexual selection consistently acted on a single part of the body, and it is unlikely that Sauropoda is the exception to this. In summary, there is no convincing evidence that sexual selection was the primary force driving the evolution of sauropod necks. While a subsidiary role for sexual selection cannot be discounted, the traditional hypothesis that sauropod necks evolved primarily due to the feeding benefits that they conferred is, by comparison, far better supported. “
“The contemporary distribution of organisms cannot be understood without knowing how species have responded to the geologic and climatic history of their environments. Genetic studies related to the demographic history of wildlife species can help us to elucidate the role of climate changes and other environmental forces in shaping patterns of distribution and population structure of the species.