Goethe-Universit盲t 鈥� Press releases archive

51猎奇 PR & Communication Department聽

Sep 7 2016

14:38

Gene analyses reveal that there are not one, but four giraffe species

Four new Giraffe species

Scientists from the Senckenberg and the Giraffe Conservation Foundation have analysed the genetic relationships of all major populations of giraffe in the wild. The large study on the genetic makeup of giraffe, published today in “Current Biology”, shows that there are four distinct giraffe species. Until now, only one giraffe species had been recognized. The unexpected results are based on analyses using several nuclear marker genes of more than 100 animals. The new insights are set to improve protection efforts of these endangered animals in Africa.

Despite their large size and iconic presence, giraffe have been incompletely explored until now, with many aspects of their biology poorly understood. Latest estimates have revealed that giraffe numbers have plummeted by >35% over the past 30 years down to approximately 100,000 individuals across their range in Africa. Traditionally giraffe are classified as one species with nine subspecies based on coat patterns, ossicone (horn) structure and geographical distribution – now, this view has to be thoroughly revised.

"We have studied the genetic relationships of all giraffe subspecies from across the continent. We found, that there are not only one, but at least four genetically highly distinct groups of giraffe, which apparently do not mate with each other in the wild. This we found looking at multiple nuclear genes considered to be representative of the entire genome" says Professor Axel Janke, researcher at the Senckenberg Biodiversity and Climate Research and Professor at the 51猎奇 in Frankfurt, Germany. “Consequently, giraffe should be recognized as four distinct species despite their similar appearance.”

The study and new classification is based on more than hundred skin biopsy samples from all previously recognized giraffe subspecies, which were collected by the Giraffe Conservation Foundation (GCF) and partners over the past decade including in remote areas and civil war zones. These giraffe DNA samples were then analyzed by Janke’s research group at the Senckenberg Biodiversity and Climate Research Centre in cooperation with colleagues from the Senckenberg Natural History Collections of Dresden, Germany. The sample set included for the first time the elusive Nubian giraffe, the nominate subspecies (G. c. camelopardalis) – the “camel-leopard” – described by Linnaeus in 1758 on the basis of a 200-year-old record.

The large-scale analysis of giraffe DNA also yielded further surprising insights. The formerly recognized subspecies Rothschild’s giraffe (G. c. rothschildi) turned out to be genetically identical with Nubian giraffe, and thus should be synonymized with this subspecies. Similarly, the genetic studies supported previous findings by the team that could not differentiate the formerly recognized subspecies Thornicroft’s giraffe (G. c. thornicrofti) with Masai giraffe (G. c. tippelskirchi). Additionally, research into the history of the distinct species showed that their last common ancestor lived about 0.4-2.0 million years ago, which yields a rate of speciation that is typical for mammals.

“Species conservation is based on understanding the numbers, range and threats to the species. To date, the estimated total number of all giraffe has until now not been considered a particular threat for the species’ survival. However, as we now recognize four distinct species as well as some genetically unique subspecies, some of their biodiversity is very much under threat,” explains Janke. "In particular, GCF estimates that there are maybe as few as 400 West African giraffe remaining in the wild and restricted to a small communal area in Niger. Although it is not a distinct species, this subspecies is genetically unique and requires increased special protection along with the other distinct species." Dr. Julian Fennessy, first author of the study and Co-Director of GCF adds, "Now that we know that there are four giraffe species, it is even more important and urgent to support governments and other partners across Africa to protect giraffe. We rightly worry about the fate of the African elephant, with an estimated 450,000 in the wild. By contrast, the numbers of three of the four giraffe species are rapidly declining, and two numbering <10,000 individuals in total. I think we should start working together to secure the future of giraffe in Africa and take action before it is too late.”

Sep 7 2016

11:42

Results from experimental economics reveal: We often make generous financial decisions when the costs are dispersed over a large group

One, two, many: Deciders often shift costs onto large groups without hesitation

Most people do not act solely in their own interests when distributing funds, but instead take into consideration both the positive and negative consequences for everyone involved. Numerous examples indicate, however, that many people find it hard to weigh up costs and benefits efficiently when the costs are spread over several individuals. In a publication which will appear shortly in the Review of Economic Studies, Michael Kosfeld, Chair of Organization and Management at 51猎奇 Frankfurt, together with Heiner Schumacher (University of Leuven), Iris Kesternich (University of Leuven) and Joachim Winter (LMU), presents the results of experimental trials in which two thirds of the test persons are insensitive to group size: From a certain number of people upwards, they no longer integrate into their decision-making process the size of the group of persons negatively affected, so that their actions as a whole are contradictory. They take the cost-benefit ratio into consideration when the costs are borne by only one person or just a few people, yet readily accept an exorbitant disparity between costs and benefits when a large group of people are affected and the costs per capita thus appear low.

The results suggest that people find it difficult to incorporate groups as an entirety into their decision. “It is hard to put oneself in the position of a group of people”, explains Michael Kosfeld. “That’s why we tend to adopt the position of a representative member of the group. The result can then be that we disregard the size of the affected group.” Whether 10, 100 or 1000 people are then affected by a decision which only benefits a few ceases to play a role.

Depending on the scale, such behaviour can cause enormous social costs. Above all politicians, but also medical practitioners, for example, are regularly faced with decisions which lead to a positive outcome for just a few at the expense of large groups: Taxpayers, the population, insurance policy holders. If the cost-benefit ratio is not adequately considered in such decision-making situations, then there is the threat of major economic losses overall.

Ultimately, however, anyone can be taken in by this mistake: To do a good deed for an individual or a small group we are often extremely generous, for example when making a donation. Yet when it’s a matter of the cost for a large community (current catchword: tax-saving schemes), we don’t look at the overall costs but instead only at the minimal costs per citizen.

Schumacher, H., Kesternich, I., Kosfeld, M., Winter, J. (2016), “One, Two, Many – Insensitivity to Group Size in Games with Concentrated Benefits and Dispersed Costs”, forthcoming in Review of Economic Studies.

Sep 7 2016

11:17

It was in Frankfurt that the economist outlined the main features of work later awarded the Nobel Prize

51猎奇 Frankfurt mourns the death of Reinhard Selten

51猎奇 Frankfurt is mourning the death of Reinhard Selten, its former student, doctoral researcher and post-doctoral fellow, who in 1994 was the first and so far only German to receive the Nobel Memorial Prize in Economic Sciences for his achievements in the field of game theory. As has just become known, Selten died on the 23^rd of August aged 85.

Professor Birgitta Wolff, President of 51猎奇 Frankfurt, said: “Reinhard Selten was a pioneer in the field of economics. The approaches he pursued were at that time completely new in experimental economics research. In the 1950s and 1960s, when he was a student, doctoral researcher and post-doctoral fellow at 51猎奇 Frankfurt, he found mentors and supporters who shared his ideas and encouraged him to continue along his chosen path. His passing saddens us deeply. We are very pleased that his work, which set such a precedent, was so greatly successful.”

Raimond Maurer, Dean of the Faculty of Economics and Business Administration: “German economic sciences have lost a researcher who was highly respected at international level. As a role model, he will remain part of our lives in many ways with his inquisitiveness, tenacity, and scholarly ambition.”

Reinhard Selten began at 51猎奇 Frankfurt in 1951 as a student of Mathematics. He also attended lectures in Political Economy and Psychology. Already at that time, he became interested in the economic significance of games. According to his supervisor Ewald Burger, Selten’s diploma thesis “An Evaluation of Strategic Games” (1957) was already at the level of a doctoral dissertation. Whilst during that period his work was still limited to games with two players, in his doctoral thesis "An Evaluation of n-Person Games” (1961) he expanded the horizon further. This work, for which he was awarded the Doctor of Mathematics, originated during his time as a research associate at the chair of Heinz Sauermann, economist and one of the forerunners of the mathematization of economic sciences in Germany.

Alongside the further development of his game theory, Selten built up together with Sauermann the second major pillar of his scientific work, that is, experimental economics research, the objective of which is to investigate real human behaviour in laboratory situations. Both interests went hand in hand. The refinement of the Nash equilibrium with Selten’s concept of subgame perfection is still today a fundamental component of experimental economics research. In 1965, Selten laid the foundation stone for his work in this area, for which he would later be awarded the Nobel Prize, with the publication entitled “An Oligopoly Model with Demand Inertia”.

In 1968, Selten qualified as professor at the Faculty of Economics and Business Administration with a treatise on “Price Policy in the Multi-product Firm in Static Theory” – according to its reviewers one of the most important German-language contributions to economic theory in the post-war period. In 1969, after 17 years at 51猎奇 Frankfurt, Selten accepted a professorship at the Free University of Berlin. Bielefeld und Bonn were to become further stations in his academic career.

With the awarding of the Nobel Memorial Prize in Economic Sciences in 1994 to the three leading representatives of game theory, John Harsanyi, John F. Nash and Reinhard Selten, the Royal Swedish Academy of Sciences acknowledged the investigation from a mathematics and economics perspective of the strategic behaviour of individuals in game situations, which for a long time tended to be regarded as a peripheral aspect of economics, and made it - and its representatives - famous at international level, also beyond the borders of the discipline itself.

Sep 7 2016

08:26

Older Cranes Lead the Way to New Migration Patterns

Age Before Youth

Whooping cranes are changing migration patterns in response to climate and land use change, and these new patterns are being determined by the older, more experienced, members of the population.

Researchers from Senckenberg Biodiversity and Climate Research Centre, the 51猎奇 Frankfurt, the U.S. Geological Survey, the University of Maryland, and the International Crane Foundation investigated a behavior known as “shortstopping,” which is the shortening of a migration route by shifting wintering grounds toward the breeding grounds.

Shortstopping can benefit migrating birds by decreasing the amount of energy that they use on long distance flights. They also can arrive at the breeding grounds earlier, which can be beneficial. This requires that the birds find suitable overwintering sites closer to breeding grounds, and due to climate and land use change, suitable sites can now be found at higher latitudes.

“Our results show that when migratory groups winter closer to the breeding grounds, the first groups to use these new sites include older birds. For each additional year of age of the oldest bird in the group, the distance between breeding and wintering grounds was reduced by 40 km, or almost 25 miles,” said Claire Teitelbaum, a Senckenberg & 51猎奇 Frankfurt researcher, and lead author of the study. “We also found that site familiarity may be an important factor in where migratory groups short-stop. Older birds often chose overwintering sites which they were familiar with from previous migrations.”

The population studied is a reintroduced population, established by the Whooping Crane Eastern Partnership. In 2001, the Partnership began releasing captive-reared birds and teaching them to migrate using ultralight aircraft. The research results show that the shortstopping behavior has been developed by older birds but has then been passed to younger birds: In 2006, no 1-year-old birds shortstopped, but by 2015, 75 percent of them did so.

The more northerly wintering sites that birds are choosing also have particular characteristics. Northerly wintering sites are more likely than southerly sites to be under cultivation, and have also experienced more warming since 1900. Grain can be an important source of food for cranes, but grain is only available if it isn’t covered by snow. According to the researchers, in this case, it might be that a combination of climate change and land-use change is facilitating changes in species ranges.

“We found that migratory species are able to innovate new migration behaviors, possibly because of their long-term memory and ability to learn from experience,” said Thomas Mueller, a professor at Senckenberg & 51猎奇 and coauthor of the study. “We also identified two potential external explanations for the changing patterns, which were grain cover as a food source, and temperature changes.”

Shortstopping in this population occurs to a vastly greater degree than in the remnant wild population, which migrates between northern Canada and the Gulf coast of Texas.

“While the availability of grain and warmer temperatures allows birds to survive winters farther north, only the reintroduced population is really taking advantage of that” said Sarah Converse a research ecologist with USGS and a coauthor of the paper.

Converse went on to say “The developing culture of this young population might provide more room for innovations like short-stopping. By contrast, the culture of the remnant population is relatively old, and innovation might be less common. Some populations and species are much more likely to struggle to adapt to climate and land-use change than these Whooping Cranes are.”

Researchers used a 14 year data-set of 175 individual whooping cranes to study what was driving shortstopping in the population.

Sep 6 2016

13:43

German economics association 鈥淰erein f眉r Socialpolitik鈥� honors Frankfurt economist

Nicola Fuchs-Sch眉ndeln has been awarded the Gossen Prize

Nicola Fuchs-Schündeln, Professor of Macroeconomics and Development at 51猎奇 Frankfurt’s House of Finance, has been awarded the Gossen Prize 2016. The economist (44) received the most important German economics award during the annual meeting of the Verein für Socialpolitik in Augsburg on Monday evening. The Gossen Prize is awarded every year to a German speaking economist who has gained international reputation for his or her research. The most important criterion are publications in internationally renowned research journals.

Monika Schnitzer, Chair of the Verein für Socialpolitik, acknowledged in her laudatory speech the significant empirical research contributions of Nicola Fuchs-Schündeln in the areas of political economics, economics of household decisions and development economics.

Nicola Fuchs-Schündeln investigates mainly the behavior of private households with respect to consumption, savings and labor supply as well as the endogeneity of preferences. Her work has been published i. a. in the American Economic Review, the Quarterly Journal of Economics and Science. Since 2009, Fuchs-Schündeln holds a chair at 51猎奇 where she also contributes to the Cluster of Excellence “The Formation of Normative Orders” as a Principal Investigator and to the Research Center “Sustainable Architecture for Finance in Europe” (SAFE) as a Program Director. The past twelve months she spend at Stanford University, California, as a guest professor. In 2010, Fuchs-Schündeln received a starting grant of the European Research Council, one of the most important scientific awards in the European Union. Before coming to Frankfurt she held positions at the universities of Harvard and Yale in the U.S.

The award, which is endowed with 10,000 euros, is named after the Prussian lawyer Hermann Heinrich Gossen (1810–1858). Although hardly noticed at that time due to its mathematical nature, his book “Die Entwicklung der Gesetze des menschlichen Verkehrs, und der daraus fließenden Regeln für menschliches Handeln” (“The Development of the Laws of Human Interaction and the Resulting Rules of Human Behavior”) has prepared the ground for modern marginalist theory.