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ECOWAS

The Economic Community of West African States (ECOWAS; also known as CEDEAO in French and Portuguese) is a regional political and economic union of fifteen countries located in West Africa. Collectively, these countries comprise an area of 5,114,162 km2 and have an estimated population of over 424.34 million.

Considered one of the pillar regional blocs of the continent-wide African Economic Community (AEC), the stated goal of ECOWAS is to achieve "collective self-sufficiency" for its member states by creating a single large trade bloc by building a full economic and trading union. Additionally, ECOWAS aims to raise living standards and promote economic development. The union was established on 28 May 1975, with the signing of the Treaty of Lagos, with its stated mission to promote economic integration across the region. A revised version of the treaty was agreed and signed on 24 July 1993 in Cotonou, the largest city in Benin.

ECOWAS's fundamental principles rely on equity, inter-dependence, solidarity, co-operation, nonaggression, regional peace, promotion of human rights, and economic and social justice.

Notably among ECOWAS's protocols and plans are the ECOWAS Free Movement of Persons, Residences and Establishment Protocol and the Ecotour Action Plan 2019–2029. The Free Movement of Persons Protocol permits citizens the right to enter and reside in any member state's territory, and the Ecotour Action Plan aims to develop and integrate the tourist industry of each member state.

ECOWAS also serves as a peacekeeping force in the region, with member states occasionally sending joint military forces to intervene in the bloc's member countries at times of political instability and unrest.

In 2024, Niger, Burkina Faso, and Mali announced their withdrawal from the bloc. The countries had earlier been suspended from ECOWAS due to military takeovers of their respective governments.

Member states
Upon its foundation, ECOWAS had 15 member states: eight French-speaking, five English-speaking, and two Portuguese-speaking. All current members joined the community as founding members in May 1975, except Cape Verde which joined in 1977.

Morocco officially requested to join ECOWAS in February 2017. The application was endorsed in principle at the Summit of Heads of State in June 2017. However, Morocco's bid for membership was stalled as West African economic actors feared goods imported through Morocco's free trade agreements would flood the market of states within ECOWAS.

States that have withdrawn or been suspended
Arabic-speaking Mauritania was one of the founding members of ECOWAS in 1975 and decided to withdraw in December 2000. Mauritania signed a new associate-membership agreement in August 2017.

Mali was suspended from ECOWAS on 30 May 2021, following its second military coup within nine months. Guinea was also suspended on 8 September 2021, shortly after a military coup took place in the country. Sanctions were placed on both countries on 16 September. On 10 January 2022, Mali announced its decision to close its borders and recalled several ambassadors with ECOWAS in response to sanctions imposed for deferring elections for four years. On 28 January 2022, Burkina Faso was suspended from ECOWAS following a military coup. Niger was suspended from ECOWAS after the 2023 coup d'état and threatened with military intervention if President Mohamed Bazoum is not restored to office, causing the Nigerien crisis. Additionally, ECOWAS closed all land and air borders between other member states and Niger and instituted a no-fly zone on all commercial flights to and from Niger. The suspension removed all commercial and financial transactions and froze Niger's assets in ECOWAS central banks. On 16 September 2023, Niger, Mali, and Burkina Faso formed a military alliance, the Alliance of Sahel States, following ECOWAS's threat to intervene to restore civilian rule in Niger. On 21 November 2023, Niger's military government asked the ECOWAS regional court to order the lifting of sanctions imposed on the country. Until the coup, aid from countries like the United States and international organizations like ECOWAS accounted for almost half of Niger's annual budget. Following Niger's ECOWAS suspension, Niger's neighbours closed their borders to the country and 70 percent of its electricity, coming from Nigeria, was cut off. While these sanctions and consequences that have followed have impacted the individuals and economy of Niger, the government is not backing down. As a result of the suspension, children have not been able to attend school due to lack of supplies, and businesses are shutting down due to rising costs. Further, the ECOWAS lawyer pointed out that the Nigerien government is not recognized by ECOWAS and therefore does not have the power to ask the regional court for a removal of these sanctions.

On 28 January 2024, Niger, Mali, and Burkina Faso announced via a joint statement that they were withdrawing from ECOWAS "without delay". The three nations, all of which are currently ruled by military juntas, accused ECOWAS of implementing "inhumane" sanctions in order to reverse the coups in each nation. Under the ECOWAS protocol, immediate withdrawal is not possible, and the three member states could remain in the bloc for up to a year. ECOWAS said in a statement that "Burkina Faso, Niger and Mali remain important members of the Community and the Authority remains committed to finding a negotiated solution to the political impasse."

On 24 February 2024, ECOWAS announced that it was lifting some sanctions against Niger, Mali and Burkina Faso. For Niger this included the border closures, the freezing of central bank and state assets, the suspension of commercial transactions, and the no-fly-zone for commercial flights to and from Niger. However, the political sanctions and targeted sanctions would remain in force. The communiqué said this was done for humanitarian reasons, but it was seen as a gesture of appeasement to dissuade the three junta-led states from withdrawing from the bloc. ECOWAS also lifted sanctions on Guinea and Guinea-Bissau.

Statistics for population, nominal GDP and purchasing power parity GDP listed below are taken from World Bank estimates for 2015, published in December 2016. Area data is taken from a 2012 report compiled by the United Nations Statistics Division.

History
ECOWAS was formed initially from the region's former French, British and Portuguese colonies, and independent Liberia, following post-colonial independence throughout the region (particularly in the 1960s and 1970s). At independence, many African states were challenged in increasing economic development. Because these states could not address problems individually, there was a need for a regional approach and thus ECOWAS was founded. ECOWAS was formed to provide regional economic cooperation, but has since evolved to include political and military cooperation, as well.

The union was established on 28 May 1975, with the signing of the Treaty of Lagos, with its stated mission to promote economic integration across the region. A revised version of the treaty was agreed and signed on 24 July 1993 in Cotonou. Considered one of the pillar regional blocs of the continent-wide African Economic Community (AEC), the stated goal of ECOWAS is to achieve "collective self-sufficiency" for its member states by creating a single large trade bloc by building a full economic and trading union.

ECOWAS also serves as a peacekeeping force in the region, with member states occasionally sending joint military forces to intervene in the bloc's member countries at times of political instability and unrest. ECOWAS facilitates peacekeeping through systematic collaboration with civil society, cooperation with development policies, and other activities with the goal to meet sub-regional security challenges. It has played an important role in monitoring transitional election in West Africa, and these mediation efforts have even been recognized within and outside the continent of Africa. In recent years these included interventions in Ivory Coast in 2003, Liberia in 2003, Guinea-Bissau in 2012, Mali in 2013, and The Gambia in 2017. Since its creation, ECOWAS has sent peacekeeping forces seven times.

In 2011, ECOWAS adopted its development blueprint for the next decade, Vision 2020, and, to accompany it, a Policy on Science and Technology (ECOPOST). However, it has had trouble achieving the goals outlined in the policy.

Covering a region known as a "coup belt", ECOWAS, since the 1990s, has attempted to defend the region's shift towards democracy against authoritarian attacks. According to the BBC, since 1990, 78% of the 27 coups in sub-Saharan Africa have taken place in former French colonies. This has led some to question whether French influence in Africa has a destabilising impact. The transition governments in Mali and Burkina Faso cancelled military agreements that allow for French troops to operate on their territory, and in the case of Mali, removed French as an official language. However, the group has been cited for mild and ineffective responses in the early 2020s, when three member countries experienced military coups d'état – two in Mali, one in Guinea, and two in Burkina Faso. When a fourth member, Niger, experienced a coup d'état in July 2023, ECOWAS was vocal in its condemnation and raised the possibility of military action if the deposed president was not reinstated by 7 August 2023. Due to the Nigerien military's refusal to restore civilian rule, ECOWAS activated its standby force composed of all other members except for Mali, Burkina Faso, Guinea and Cape Verde.

On 6 July 2024, the military leaders of Niger, Mali, and Burkina Faso signed a new pact, rebuffing ECOWAS. The agreement aimed to strengthen military cooperation and counter-terrorism efforts in the Sahel region. The move is seen as a snub to ECOWAS, which has been pressing for a return to civilian rule in the three countries. The pact also includes provisions for intelligence sharing, joint military operations, and a mutual defense clause.

Overall
ECOWAS consists of two operating institutions to implement policies: the ECOWAS Commission and the ECOWAS Bank for Investment and Development (EBID) – formerly known as the Fund for Cooperation, until it was renamed in 2001.

In addition, ECOWAS includes the following institutions: ECOWAS Commission, Community Court of Justice, Community Parliament, ECOWAS Bank for Investment and Development (EBID), West African Health Organisation (WAHO), and the Inter-Governmental Action Group against Money Laundering and Terrorism Financing in West Africa (GIABA).

ECOWAS includes two sub-regional blocks:

 * The West African Economic and Monetary Union (also known by its French-language acronym UEMOA) is an organisation of eight, mainly French-speaking, states within ECOWAS which share a customs union and currency union. Established in 1994 and intended to counterbalance the dominance of English-speaking economies in the bloc (such as Nigeria and Ghana), members of UEMOA are mostly former territories of French West Africa. The currency they all use is the CFA franc, which is pegged to the euro.
 * The West African Monetary Zone (WAMZ), established in 2000, comprises six mainly English-speaking countries within ECOWAS which plan to work towards adopting their own common currency, the eco.

ECOWAS operates in three co-official languages—French, English, and Portuguese.

Regional security co-operation
ECOWAS nations assigned a non-aggression protocol in 1990 along with two earlier agreements in 1978 and 1981. They also signed a Protocol on Mutual Defence Assistance in Freetown, Sierra Leone, on 29 May 1981, that provided for the establishment of an Allied Armed Force of the Community.

Community Parliament
The Community Parliament consists of 115 members, distributed based on the population of each member state. This body is headed by the Speaker of the Parliament, who is above the Secretary General.

Expanded ECOWAS Commission
For the third time since its inception in 1975, ECOWAS is undergoing institutional reforms. The first was when it revised its treaty on 24 July 1993; the second was in 2007 when the Secretariat was transformed into a Commission. As of July 2013, ECOWAS now has six new departments (Human Resources Management; Education, Science and Culture; Energy and Mines; Telecommunications and IT; Industry and Private Sector Promotion). Finance and Administration to Sierra Leone has been decoupled, to give the incoming Ghana Commissioner the new portfolio of Administration and Conferences.

Community Court of Justice
ECOWAS Community Court of Justice was created by a protocol signed in 1991 and was later included in Article 6 of the Revised Treaty of the Community in 1993. However, the Court did not officially begin operations until the 1991 protocol came into effect on 5 November 1996. The jurisdiction of the court is outlined in Article 9 and Articles 76 of the Revised Treaty and allows rulings on disputes between states over interpretations of the Revised Treaty. It also provides ECOWAS Council with advisory opinions on legal issues (Article 10). Like its companion courts, the European Court of Human Rights and East African Court of Justice, it has jurisdiction to rule on fundamental human rights breaches.

Sporting and cultural exchange
ECOWAS nations organise a broad array of cultural and sports events under the auspices of the body, including the CEDEAO Cup in football, the 2012 ECOWAS Games and the Miss CEDEAO beauty pageant.

The Community Heads of State and Government adopted African Traditional Wrestling as the Community sport, and through its specialised agency in charge of youth and sports development, the Ouagadougou-based ECOWAS Youth and Sports Development Centre (EYSDC), has consistently organised the yearly ECOWAS African Wrestling Tournament mainly in Dakar (Senegal) and Niamey (Niger) based on a harmonized African wrestling code.

The Community, through the EYSDC, also organized 2 editions of ECOWAS International Cycling tour, taking close to 100 riders from all member states, from Lagos to Accra and then from Lagos to Abidjan. In addition to the sports and well-being objective of the tour, the race also served to demonstrate and put into practice ECOWAS protocol on free movement of goods and persons.

In 2019, the EYSDC instituted ECOWAS Abuja International Marathon. The first edition brought together international marathoners from West Africa, Kenya, Ethiopia and Cameroon.

Similarly, the Community, through its specialised agency, promotes regional sports development by offering sponsorship to regional sports federations and specialized disciplines such as the West African Deaf Sports Union (WADSU), the West African Liaison Office of the International Council for Military Sports (WALO-CISM), the Region 2 of the African Athletics Federation, and the West African University Games (WAUG), among others.

Youth
The ECOWAS Youth Policy Strategic Plan of Action (SPAO) is a 10-year plan that aims to promote youth development and empowerment in the Economic Community of West African States (ECOWAS). The SPAO was adopted in 2016 and is based on the pillars of education and training, employment and entrepreneurship, health and well-being, peace and security, and governance and participation.

The SPAO identifies a number of challenges facing youth in ECOWAS, including high unemployment rates, lack of access to education and training, and poor health outcomes. The plan sets out a number of strategies to address these challenges, including investing in education and training, creating jobs and supporting entrepreneurship, improving access to health care, promoting peace and security, and strengthening youth participation in governance.

West African Economic and Monetary Union (UEMOA)
The West African Economic and Monetary Union (WAEMU, also known as UEMOA from its name in French, Union économique et monétaire ouest-africaine) is an organisation of eight, mainly francophone West African states within ECOWAS, previously colonies of French West Africa. It was established to promote economic integration among countries that share the CFA franc as a common currency. UEMOA was created by a Treaty signed at Dakar, Senegal, on 10 January 1994, by the heads of state and governments of Benin, Burkina Faso, Ivory Coast, Mali, Niger, Senegal, and Togo. On 2 May 1997, Guinea-Bissau, a former Portuguese colony, became the organisation's eighth (and only non-francophone) member state.

UEMOA is a customs union and currency union between the members of ECOWAS. Its objectives include:
 * Greater economic competitiveness, through open markets, in addition to the rationalisation and harmonisation of the legal environment
 * The convergence of macro-economic policies and indicators
 * The creation of a common market
 * The co-ordination of sectoral policies
 * The harmonisation of fiscal policies

Among its achievements, the UEMOA has successfully implemented macro-economic convergence criteria and an effective surveillance mechanism. It has adopted a customs union and common external tariff and has combined indirect taxation regulations, in addition to initiating regional structural and sectoral policies. A September 2002 IMF survey cited the UEMOA as "the furthest along the path toward integration" of all the regional groupings in Africa.

ECOWAS and UEMOA have developed a common plan of action on trade liberalisation and macroeconomic policy convergence. The organizations have also agreed on common rules of origin to enhance trade, and ECOWAS has agreed to adopt UEMOA's customs declaration forms and compensation mechanisms.

However, within the region, there has been a low level of integration with an increase in income disparities since the creation of WAEMU. Côte d'Ivoire had the highest GDP per capita in 2022 at US$1,950 while Niger had the lowest one at US$484. In the same year, Côte d'Ivoire and Senegal alone accounted for more than 60% of the unions' exports. Additionally, there is a large discrepancy in countries' economic performance over the 2010 decade; the best performance was recorded by Côte d'Ivoire (annual growth rate of 6.72%) and the lowest one by Guinea Bissau (3.85%). However, positive progress has been made in economic distribution since the foundation of WAMEU, with the mean dispersion of economic growth in the region being 1.26 before the creation and 0.73 after.

Membership

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West African Monetary Zone
Formed in 2000, the West African Monetary Zone (WAMZ) is a group of six countries within ECOWAS that plan to introduce a common currency called the eco. The six member states of WAMZ are Gambia, Ghana, Guinea, Nigeria and Sierra Leone who founded the organisation together in 2000 and Liberia who joined on 16 February 2010. Apart from Guinea, which is francophone, they are all English-speaking countries. Along with Mauritania, Guinea opted out of the CFA franc currency shared by all other former French colonies in West and Central Africa.

The WAMZ attempts to establish a strong stable currency to rival the CFA franc, whose exchange rate is tied to that of the euro and is guaranteed by the French Treasury. The eventual goal is for the CFA franc and eco to merge, giving all of West and Central Africa a single, stable currency. The launch of the new currency is being developed by the West African Monetary Institute based in Accra, Ghana.

Membership

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 * 🇬🇭 (Founding Member)
 * 🇬🇳 (Founding Member)
 * 🇱🇷 (Joined on 16 February 2010)
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 * 🇸🇱 (Founding Member)

The Free Movement of Persons, Residence and Establishment Protocol
In May 1979, ECOWAS adopted a Free Movement of Persons, Residence and Establishment Protocol, which permits citizens to enter, reside, and establish economic activities in the territory of member states. There were three phases of implementation to achieve the goals of the protocol. Over the course of five years, Phase I eliminated the need for visas for stays of up to 90 days within the ECOWAS territory. Phase II attempted to extend residency to citizens in host ECOWAS states to seek income-earning employment after obtaining an ECOWAS residence card. Phase II also required member states to grant migrant workers equal treatment in areas such as employment, participation, social and cultural activities, and in certain cases of job loss, re-employment, and training. Phase III centered on the facilitation and establishment of business through the right of citizens to manage economic activities in countries other than their country of origin. However, this right has not been fully established in the ECOWAS region. While these three phases promoting freedom of movement within the ECOWAS region is more advanced than in any other regional grouping in Africa, only the first phase has been fully implemented by all ECOWAS countries. The complete implementation of the 90-day visa-free window enhanced human mobility in the region, creating positive impacts on trade and economic development.

In December 2000, the ECOWAS passport was introduced as a common passport that functions as an international travel document, and member states are currently in the process of implementing a joint visa for non-ECOWAS citizens. Additionally, ECOWAS has worked to ease the movement of people transported in private and commercial vehicles by implementing policies that enable vehicles to enter and reside in a State for up to ninety days. Most ECOWAS states have instituted an ECOWAS brown card, which provides prompt, fair, and immediate compensation for any motor accident which occurs outside a motorist's home-country.

While monitoring committees exist to ensure all three phases of the protocol are successfully implemented, their work is vague and has not been credited with effective and efficient production of data. The largest challenges assosicated within the implementation of the protocol occur due to lack of commitment and enforceability. More so, there is a lack of access to readily available migrant information in the ECOWAS region. This poses a barrier to freedom of movement as immigration officials in member states are unaware that individuals who hold valid travel documents can enter their country freely. Therefore, West African migrants, who are entitled to enter through regular channels, leave their countries without proper travel documents and enter other countries illegally. This illegal and irregular entry poses a barrier towards gaining reliable travel statistics.

For example, Francophone countries in the region have issued national identity cards that can be used similarly to a passport. These cards permit citizens to cross borders after presenting their identity cards. However, Anglophone countries have only just begun distributing a similar form of identification. Consequently, immigration officials in Anglophone countries commonly reject Francophone national identity cards and do not permit Francophone citizens to cross into their borders. Further, these structural barriers are exasperated between different social classes. Middle-class individuals typically experience a smoother border-crossing process than working-class individuals and impoverished citizens who do not have travel documents and are not fluent in the language of the countries they are crossing into.

Transport
A Trans-ECOWAS project, established in 2007, plans to upgrade railways in this zone.

Tourism
In 2019, ECOWAS unveiled its Ecotour Action Plan 2019 – 2029. It focuses on tourism heritage protection and development and on the development of standards, regulations, and control systems. The plan includes five programs for implementation, and detailed mechanisms for monitoring and evaluation. Ecotourism is not specifically developed, yet it has been mentioned that the program has the opportunity to create linkages between institutions and stakeholder collaboration to suit ecotourism projects that prioritize community, biodiversity, and socioeconomics. The Ecotour Plan prioritizes local development, especially in generating skilled and unskilled jobs for marginalized individuals, and aims to make the ECOWAS region a first-class tourist destination in Africa. During its creation, ECOWAS ministers also called on ecotourism programs to protect threatened biodiversity in the Guinean Forests, which span into seven ECOWAS member states. Similar to the Free Movement of People Protocol, Ecotour aims to integrate aviation and ground transportation. ECOWAS hopes that this regional approach will allow states to fight against pandemics such as COVID-19 to restore tourism and ecosystems. Ecotour works to create increasing returns to its members' economies by lowering transport costs, developing hospitality training centers and creating a more integrated use of digital technology.

As of March 2023, Council members mentioned that phases one and two of the Ecotour Action Plan have come to an end and that the community is moving into phase three and four, which focuses on the development of tourist accommodations establishments, and a proposal for a regional mechanism to enforce tourist regulations. By the end of phase five, ECOWAS hopes to have unified accommodations in hotels, ecolodges, motels, apart hotels, and hostels. In April 2023, tourism experts met to amend the new text for tourist accommodations in the ECOWAS region. This phase is critical to the success of the Ecotour plan as the lack of a regulatory system has been a barrier to the development of the tourism sector, despite its ability to increase member states' economies. During this conference, ministers improved the tourism industry by adopting standards for hotel services. Mrs. Massandjé Toure-Liste, the ECOWAS Commission's Commissioner for Economic Affairs and Agriculture, pointed out the improvements in the tourist sector due to the African Continental Free Trade Area, a trade agreement signed by 44 members of the African Union which creates a single market for goods and services. Mrs. Toure-Liste praised the trade area for providing development opportunities, economic growth, and boosting regional integration.

title: ECOWAS


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Paweł Jasienica

Paweł Jasienica was the pen name of Leon Lech Beynar (10 November 1909 – 19 August 1970), a Polish historian, journalist, essayist and soldier.

During World War II, Jasienica (then, Leon Beynar) fought in the Polish Army, and later, the Home Army resistance. Near the end of the war, he was also working with the anti-Soviet resistance, which later led to him taking up a new name, Paweł Jasienica, to hide from the communist government of the People's Republic of Poland. He was associated with the Tygodnik Powszechny weekly and several other newspapers and magazines. He is best known for his 1960s books on Polish history—on the Kingdom of Poland under the Piast dynasty, the Jagiellon dynasty, and the elected kings of the Polish–Lithuanian Commonwealth. Those books, still popular, played an important role in popularizing Polish history among several generations of readers.

Jasienica became an outspoken critic of the censorship in the People's Republic of Poland, and as a notable dissident, he was persecuted by the government. He was subject to significant invigilation (oversight) by the security services, and his second wife was in fact an agent of the communist secret police. For a brief period marking the end of his life, his books were prohibited from being distributed or printed.

Youth
Beynar was born on 10 November 1909 in Simbirsk, Russia, to Polish parents, Mikołaj Beynar and Helena Maliszewska. His paternal grandfather, Ludwik Beynar, fought in the January Uprising and married a Spanish woman, Joanna Adela Feugas. His maternal grandfather, Wiktor Maliszewski, fought in the November uprising. Both of his grandfathers eventually settled in the Russian Empire. His father, Mikołaj, worked as an agronomist. Beynar's family lived in Russia and Ukraine—they moved from Simbirsk to a location near Bila Tserkva and Uman, then to Kyiv until the Russian Revolution of 1917, after which they decided to settle in the independent Poland. After a brief stay in Warsaw, during the Polish–Soviet War, his family settled in Opatów, and in 1924, moved to Grodno.

Beynar graduated from gymnasium (secondary school) in Wilno (Vilnius) and graduated in history from Stefan Batory University in Wilno (his thesis concerned the January Uprising). At the university he was an active member of several organizations including Klub Intelektualistów (Intellectuals' Club) and Akademicki Klub Włóczęgów (Academic Club of Vagabonds). After graduating, he finished training for the officer cadet (podchorąży) in the Polish Army. From 1928 to 1937 he lived in Grodno, where he worked as a history teacher in a gymnasium; later he was employed as an announcer for Polish Radio Wilno. Here also, Beynar embarked on his career as author and essayist, writing for a Vilnius conservative newspaper, Słowo (The Word). On 11 November 1934 he married Władysława Adamowicz, and in 1938 his daughter Ewa was born. In 1935 he published his first history book – about King Sigismund II Augustus, Zygmunt August na ziemiach dawnego Wielkiego Księstwa (Sigismund Augustus on the Lands of the Former Grand Duchy [of Lithuania]).

World War II
During World War II, Beynar was a soldier in the Polish Army, fighting the German Wehrmacht when it invaded Poland in September 1939. He commanded a platoon near Sandomierz and was eventually taken prisoner by the Germans. While in a temporary prisoner-of-war camp in Opatów, he was able to escape with the help of some old school friends from the time his family lived there in the early 1920s. He joined the Polish underground organization, "Związek Walki Zbrojnej" (Association for Armed Combat), later transformed into the "Armia Krajowa" ("AK"; the Home Army), and continued the fight against the Germans. In the resistance he had the rank of lieutenant, worked in the local Wilno headquarters and was an editor of an underground newspaper "Pobudka". He was also involved in the underground teaching. In July 1944 he took part in the operation aimed at the liberation of Wilno from the Germans (Operation Ostra Brama). In the wake of this operation, around 19–21 August, his partisan unit, like many others, was intercepted and attacked by the Soviets. He was taken prisoner; sources vary as to whether he was to be exiled to Siberia or conscripted into the Polish People's Army. Either way he escaped and rejoined AK partisans (the Home Army 5th Wilno Brigade). For a while, he was an aide to Major Zygmunt Szendzielarz (Łupaszko) and was member of the anti-Soviet resistance, Wolność i Niezawisłość (WiN, Freedom and Independence). He was promoted to the rank of captain. Wounded in August 1945, he left the Brigade before it was destroyed by the Soviets, and avoided the fate of most of its officers who were sentenced to death. While recovering from his wounds, he found shelter in the village of Jasienica.

Post-war
After recovering from his wounds in 1945, Beynar decided to leave the resistance, and instead began publishing in an independent Catholic weekly Tygodnik Powszechny. It was then that he took the pen-name Jasienica (from the name of the place where he had received treatment for his injuries) in order not to endanger his wife, who was still living in Soviet-controlled Vilnius, Lithuania. Soon he became a member of the weekly's staff and then an editor. In 1948 he was arrested by the Polish secret police (Urząd Bezpieczeństwa) but after several weeks was released after the intervention of Bolesław Piasecki from the PAX Association. In gratitude to Piasecki, thereafter he worked with PAX, leaving Tygodnik Powszechny for PAX in 1950. In 1950, he became a director of the Polish Caritas charity. Jasienica became a member of the Crooked Circle Club, which espoused free speech and open discussion. His essays were published in Dziś i Jutro, Słowo Powszechne, Życie Warszawy, Po Prostu. From at least this period until his death he would live in Warsaw. His wife Władysława died 29 March 1965.

Over time, he became increasingly involved in various dissident organizations. In December 1959, he became a vice president of the Union of Polish Writers (Związek Literatów Polskich, ZLP). He also published in the magazine Świat (1951–1969). In 1962 he was the last president of the literary discussion society, Crooked Circle Club. In 1966 he was a vice president of the PEN Club. While in the late 1940s and 1950s he focused mostly on journalistic activity, later he turned to writing popular history in book format. In the 1960s he wrote his most famous works, historical books about history of Poland – the Kingdom of Poland in the times of the Piast dynasty, the Jagiellonian dynasty, and the era of elected kings (the Polish–Lithuanian Commonwealth). His book on Jagiellonian Poland was recognized as the best book of the year by the readers.

Jasienica was, however, very outspoken in his criticism of the censorship in the People's Republic of Poland. On 29 February 1968 during a ZLP meeting, Jasienia presented a harsh critique of the government. These acts, and in particular his signing of the dissident Letter of 34 in 1964 against censorship and his involvement in the 1968 protests led to his being labeled a political dissident, for which he suffered government persecution. Partly as a response to government's persecution of Jasienica, in 1968 the satirist Janusz Szpotański dedicated one of his anti-government poems, Ballada o Łupaszce (The Ballad of Łupaszko), written while Szpotański was in Mokotów Prison, to the writer. In the aftermath of the 1968 events, Polish communist media, and communist leader, Władysław Gomułka, on 19 March 1968, alleged that in 1948 Jasienica was freed because he collaborated with the communist regime; this allegation caused much controversy and damaged Jasienica's reputation. He was subject to much invigilation (oversight) by the security services. In December 1969, five years after his first wife's death, he remarried. This marriage proved to be highly controversial as it was discovered after his death that his second wife, Zofia Darowska O’Bretenny, had been a secret police informant before their marriage, and continued to write reports about him throughout their marriage. From 1968 until his death, his books were prohibited from being distributed or printed.

Jasienica died from cancer on 19 August 1970 in Warsaw. Some publicists later speculated to what extent his death was caused by "hounding from the party establishment". He is buried in Warsaw's Powązki Cemetery. His funeral was attended by many dissidents and became a political manifestation; Adam Michnik recalls seeing Antoni Słonimski, Stefan Kisielewski, Stanisław Stomma, Jerzy Andrzejewski, Jan Józef Lipski and Władysław Bartoszewski. Bohdan Cywiński read a letter from Antoni Gołubiew.

Work
Jasienica book publishing begun with a historical book, Zygmunt August na ziemiach dawnego Wielkiego Księstwa (Sigismund Augustus in the lands of the former Grand Duchy; 1935). He is best known for his highly acclaimed and popular historical books from the 1960s about Piast Poland, Jagiellon Poland and the Polish–Lithuanian Commonwealth: Polska Piastów (Piast Poland, 1960), Polska Jagiellonów (Jagiellon Poland, 1963) and the trilogy Rzeczpospolita Obojga Narodów (The Commonwealth of Both Nations, 1967–1972). This trilogy made him one of the most popular Polish history writers. Throughout his life he avoided writing about modern history, to minimize the influence that the official, communist Marxist historiography would have on his works. This was also one of the reasons for the popularity of his works, which were seen as a rare, legally obtainable alternative to the official version of history. His books, publication of which resumed once again after his death, were labeled as "best-selling", and became the most reprinted postwar history of Poland.

His Dwie drogi (Two ways, 1959) about the January Uprising of the 1860s represent the latest historical period he has tackled. His other popular historical books include Trzej kronikarze, (Three chroniclers; 1964), a book about three medieval chroniclers of Polish history (Thietmar of Merseburg, Gallus Anonymus and Wincenty Kadłubek), in which he discusses the Polish society through ages; and Ostatnia z rodu (Last of the Family; 1965) about the last queen of the Jagiellon dynasty, Anna Jagiellonka. His Rozważania o wojnie domowej (1978; Thoughts on Civil War) were the last book he has finished; unlike the majority of his other works, this book is ostensibly about the civil war (Chouannerie) in Brittany, France. This work does however contains numerous arguments applicable to more modern Polish history; arguments that Jasienica thought would not be allowed by the censors if the book discussed Polish history.

In addition to historical books, Jasienica, wrote a series of essays about archeology – Słowiański rodowód (Slavic genealogy; 1961) and Archeologia na wyrywki. Reportaże (Archeological excerpts: reports; 1956), journalistic travel reports (Wisła pożegna zaścianek, Kraj Nad Jangtse) and science and technology (Opowieści o żywej materii, Zakotwiczeni). Those works were mostly created around the 1950s and 1960s.

His Pamiętnik (Memoirs) was the work that he began shortly before his death, and that was never completely finished.

In 2006, Polish journalist and former dissident Adam Michnik said that: "I belong to the generation '68, a generation that has special debt to Paweł Jasienica – in fact he paid with his life for daring to defend us, the youth. I want for somebody to be able to write, at some point, that in my generation there were people who stayed true to his message. Those who never forgot about his beautiful life, his wise and brave books, his terrible tragedy."

Polish historian Henryk Samsonowicz echoes Michnik's essay in his introduction to a recent (2008) edition of Trzej kronikarze, describing Jasienica as a person who did much to popularize Polish history. Hungarian historian Balázs Trencsényi notes that "Jasienica's impact of the formation of the popular interpretation of Polish history is hard to overestimate". British historian Norman Davies, himself an author of a popular account of Polish history (God's Playground), notes that Jasienica, while more of "a historical writer than an academic historian", had "formidable talents", gained "much popularity" and that his works would find no equals in the time of communist Poland. Samsonowicz notes that Jasienica "was a brave writer", going against prevailing system, and willing to propose new hypotheses and reinterpret history in innovative ways. Michnik notes how Jasienica was willing to write about Polish mistakes, for example in the treatment of Cossacks. Ukrainian historian Stephen Velychenko also positively commented on Jasienica's extensive coverage of the Polish-Ukrainian history. Both Michnik and Samsonowicz note how Jasienica's works contain hidden messages in which Jasienica discusses more contemporary history, such as in his Rozważania....

Awards

 * Medals:

 * Order of Polonia Restituta, Grand Cross, awarded on 3 May 2007 (posthumously)
 * Order of Polonia Restituta, Knight's Cross, awarded on 22 July 1956
 * Cross of Valour, awarded by the Wilno Region Headquarters of Home Army in 1944, confirmed by Polish Ministry of Defense in 1967
 * Home Army Cross, awarded in 1967 in London

 * Awards:

 * 2007 laureate of Poland's "Custodian of National Memory" Prize.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Paweł Jasienica


text:
Vertebrate

Vertebrates are deuterostomal animals with bony or cartilaginous axial endoskeleton — known as the vertebral column, spine or backbone — around and along the spinal cord, including all fish, amphibians, reptiles, birds and mammals. The vertebrates consist of all the taxa within the subphylum Vertebrata and represent the overwhelming majority of the phylum Chordata, with currently about 69,963 species described.

Vertebrates comprise groups such as the following infraphyla and classes:
 * Agnatha or jawless fish, which include:
 * Conodonta
 * Ostracodermi
 * Cyclostomi (hagfish and lampreys)
 * Gnathostomata or jawed vertebrates, which include:
 * Placodermi
 * Acanthodii
 * Chondrichthyes or cartilaginous fish, (sharks, rays and ratfish)
 * Osteichthyes or bony fish, which include:
 * Actinopterygii or ray-finned fish, which comprises the majority of living bony fish and over half of all living vertebrates, including:
 * Cladistia (bichirs and relatives)
 * Chondrostei (sturgeons and paddlefish)
 * Holostei (bowfins and gars)
 * Teleostei (96% of living fish species)
 * Sarcopterygii or lobe-finned fish, which include:
 * Actinistia (coelacanths)
 * Dipnomorpha (lungfish)
 * Tetrapoda or limbed vertebrates
 * Amphibians (lissamphibians, as well as the extinct temnospondyls and lepospondyls)
 * Amniotes or true land vertebrates
 * Sauropsids (reptiles and birds, as well as the extinct parareptiles, dinosaurs, pterosaurs and Mesozoic marine reptiles)
 * Synapsids (mammals as well as all their extinct relatives and pelycosaurid/therapsid ancestors)

Extant vertebrates vary in body lengths ranging from the frog species Paedophryne amauensis, at as little as 7.7 mm, to the blue whale, at up to 33 m. Vertebrates make up less than five percent of all described animal species; the rest are described as invertebrates, an informal polyphyletic group comprising all that lack vertebral columns, which include non-vertebrate chordates such as lancelets.

The vertebrates traditionally include the hagfish, which do not have proper vertebrae due to their loss in evolution, though their closest living relatives, the lampreys, do. Hagfish do, however, possess a cranium. For this reason, the vertebrate subphylum is sometimes referred to as Craniata or "craniates" when discussing morphology. Molecular analysis since 1992 has suggested that hagfish are most closely related to lampreys, and so also are vertebrates in a monophyletic sense. Others consider them a sister group of vertebrates in the common taxon of Craniata.

Etymology
The word vertebrate derives from the Latin word vertebratus (Pliny), meaning joint of the spine. A similarly derived word is vertebra, which refers to any of the irregular bones or segments of the spinal column.

Anatomy and morphology
All vertebrates are built along the basic chordate body plan: a rigid axial endoskeleton (vertebral column and/or notochord) running along the length of the animal, dorsal to the gut tube, with a hollow dorsal nerve cord (the neural tube, which develops into the brain and spinal cord) running more dorsal to it. The endoskeleton continues beyond the anus and often forms an elongated tail (post-anal tail). All vertebrates also possess pharyngeal arches, as well as an iodine-concentrating organ called the endostyle, which develops into the thyroid in adults.

Vertebral column
With only one exception, the defining characteristic of all vertebrate is the vertebral column, in which the embryonic notochord found in all chordates is replaced by a segmented series of mineralized elements called vertebrae separated by fibrocartilaginous intervertebral discs, which are derived embryonically and evolutionarily from the notochord. Hagfish are the only extant vertebrate whose notochord persists and is not integrated/ replaced by the vertebral column.

A few vertebrates have secondarily lost this feature and retain the notochord into adulthood, such as the sturgeon and coelacanth. Jawed vertebrates are typified by paired appendages (fins or limbs, which may be secondarily lost), but this trait is not required to qualify an animal as a vertebrate.

Gills
All basal vertebrates are aquatic and breathe with gills. The gills are carried right behind the head, bordering the posterior margins of a series of openings from the pharynx to the exterior. Each gill is supported by a cartilaginous or bony gill arch. The bony fish have three pairs of arches, cartilaginous fish have five to seven pairs, while the primitive jawless fish have seven. The vertebrate ancestor no doubt had more arches than this, as some of their chordate relatives have more than 50 pairs of gills. In jawed vertebrates, the first gill arch pair evolved into the jointed jaws and form an additional oral cavity ahead of the pharynx. Research also suggests that the sixth branchial arch contributed to the formation of the vertebrate shoulder, which separated the head from the body.

In amphibians and some primitive bony fishes, the larvae bear external gills, branching off from the gill arches. These are reduced in adulthood, their function taken over by the gills proper in fishes and by lungs in most amphibians. Some amphibians retain the external larval gills in adulthood, the complex internal gill system as seen in fish apparently being irrevocably lost very early in the evolution of tetrapods.

While the more derived vertebrates lack gills, the gill arches form during fetal development, and form the basis of essential structures such as jaws, the thyroid gland, the larynx, the columella (corresponding to the stapes in mammals) and, in mammals, the malleus and incus.

Central nervous system
The central nervous system of vertebrates is based on the hollow dorsal nerve cord running along the dorsal aspect of the notochord. Of particular importance and unique to vertebrates is the presence of neural crest cells, which are progenitor cells critical to coordinating the functions of cellular components. Neural crest cells migrate through the body from the dorsal nerve cord during development, and initiate the formation of neuronal ganglia and structures such as the jaws and skull. The peripheral nervous system forms when neural crest cells branch out laterally from the dorsal nerve cord and migrate together with the mesodermal somites to innervate the various different structures that develop in the body.

The vertebrates are the only chordate group with neural cephalization, and their neural functions are centralized towards a series of vesicular enlargements in the head, which give rise to a brain. A slight swelling of the anterior end of the nerve cord is found in invertebrate chordates such as lancelets (a sister subphylum known as the cephalochordates), though it lacks eyes and other complex special sense organs comparable to those of vertebrates. Other chordates do not show any trends towards cephalization.

The rostral end of the neural tube is expanded by a thickening of the walls and expansion of the central canal of spinal cord into three primary brain vesicles: the prosencephalon (forebrain), mesencephalon (midbrain) and rhombencephalon (hindbrain), which are further differentiated in the various vertebrate groups. Two laterally placed retinas and optical nerves form around outgrowths from the midbrain, except in hagfish, though this may be a secondary loss. The forebrain is more well-developed in most tetrapods and subdivided into the telencephalon and diencephalon, while the midbrain dominates in many fish and some salamanders. Vesicles of the brain are usually bilaterally symmetrical, giving rise to the paired cerebral hemispheres in mammals.

The resulting anatomy of the central nervous system with a single hollow nerve cord dorsal to the gut tube, headed by a series of (typically paired) brain vesicles, is unique to vertebrates. Other invertebrates with well-developed central nervous systems such as arthropods and cephalopods, have a ventral nerve cord made of segmental ganglia on the opposite side of the gut tube, with a split brain stem circumventing the foregut around each side to form a brain on the dorsal side of the mouth.

Another distinct neural feature of vertebrates is the axonal/dendritic myelination in both central (via oligodendrocytes) and peripheral nerves (via neurolemmocytes). Although myelin insulation is not unique to vertebrates — many annelids and arthropods also have myelin sheath formed by glia cells, with the Kuruma shrimp having twice the conduction velocity of any vertebrates — vertebrate myelination is annular and non-fenestrated, and the combination of myelination and encephalization have given vertebrates a unique advantage in developing higher neural functions such as complex motor coordination and cognition. It also allows vertebrates to evolve larger sizes while still maintaining considerable body reactivity, speed and agility (in contrast, invertebrates typically become sensorily slower and motorically clumsier with larger sizes), which are crucial for the eventual adaptive success of vertebrates in seizing dominant niches of higher trophic levels in both terrestrial and aquatic ecosystems.

Molecular signatures
In addition to the morphological characteristics used to define vertebrates (i.e. the presence of a notochord, the development of a vertebral column from the notochord, a dorsal nerve cord, pharyngeal gills, a post-anal tail, etc.), molecular markers known as conserved signature indels (CSIs) in protein sequences have been identified and provide distinguishing criteria for the subphylum Vertebrata. Specifically, 5 CSIs in the following proteins: protein synthesis elongation factor-2 (EF-2), eukaryotic translation initiation factor 3 (eIF3), adenosine kinase (AdK) and a protein related to ubiquitin carboxyl-terminal hydrolase are exclusively shared by all vertebrates and reliably distinguish them from all other metazoan. The CSIs in these protein sequences are predicted to have important functionality in vertebrates.

A specific relationship between Vertebrates and Tunicates is also strongly supported by two CSIs found in the proteins Rrp44 (associated with exosome complex) and serine palmitoyltransferase, that are exclusively shared by species from these two subphyla but not Cephalochordates, indicating Vertebrates are more closely related to Tunicates than Cephalochordates.

External relationships
Originally, the "Notochordata hypothesis" suggested that the Cephalochordata is the sister taxon to Craniata (Vertebrata). This group, called the Notochordata, was placed as sister group to the Tunicata (Urochordata). Although this was once the leading hypothesis, studies since 2006 analyzing large sequencing datasets strongly support Olfactores (tunicates + vertebrates) as a monophyletic clade, and the placement of Cephalochordata as sister-group to Olfactores (known as the "Olfactores hypothesis"). As chordates, they all share the presence of a notochord, at least during a stage of their life cycle.

The following cladogram summarizes the systematic relationships between the Olfactores (vertebrates and tunicates) and the Cephalochordata.

First vertebrates

Vertebrates originated during the Cambrian explosion, which saw a rise in organism diversity. The earliest known vertebrates belongs to the Chengjiang biota and lived about 518 million years ago. These include Haikouichthys, Myllokunmingia, Zhongjianichthys, and probably Haikouella. Unlike the other fauna that dominated the Cambrian, these groups had the basic vertebrate body plan: a notochord, rudimentary vertebrae, and a well-defined head and tail. All of these early vertebrates lacked jaws in the common sense and relied on filter feeding close to the seabed. A vertebrate group of uncertain phylogeny, small eel-like conodonts, are known from microfossils of their paired tooth segments from the late Cambrian to the end of the Triassic.

From fish to amphibians

The first jawed vertebrates may have appeared in the late Ordovician (~445 mya) and became common in the Devonian period, often known as the "Age of Fishes". The two groups of bony fishes, the actinopterygii and sarcopterygii, evolved and became common. The Devonian also saw the demise of virtually all jawless fishes save for lampreys and hagfish, as well as the Placodermi, a group of armoured fish that dominated the entirety of that period since the late Silurian as well as the eurypterids, dominant animals of the preceding Silurian, and the anomalocarids. By the middle of the Devonian, several droughts, anoxic events and oceanic competition lead a lineage of sarcopterygii to leave water, eventually establishing themselves as terrestrial tetrapods in the succeeding Carboniferous.

Mesozoic vertebrates
Amniotes branched from amphibious tetrapods early in the Carboniferous period. The synapsid amniotes were dominant during the late Paleozoic, the Permian, while diapsid amniotes became dominant during the Mesozoic. In the sea, the teleosts and sharks became dominant. Mesothermic synapsids called cynodonts gave rise to endothermic mammals and diapsids called dinosaurs eventually gave rise to endothermic birds, both in the Jurassic. After all dinosaurs except birds went extinct by the end of the Cretaceous, birds and mammals diversified and filled their niches.

After the Mesozoic
The Cenozoic world saw great diversification of bony fishes, amphibians, reptiles, birds and mammals.

Over half of all living vertebrate species (about 32,000 species) are fish (non-tetrapod craniates), a diverse set of lineages that inhabit all the world's aquatic ecosystems, from the Tibetan stone loach (Triplophysa stolickai) in western Tibetan hot springs near Longmu Lake at an elevation of 5200 m to an unknown species of snailfish (genus Pseudoliparis) in the Izu–Ogasawara Trench at a depth of 8336 m. Many fish varieties are the main predators in most of the world's freshwater and marine water bodies. The rest of the vertebrate species are tetrapods, a single lineage that includes amphibians (with roughly 7,000 species); mammals (with approximately 5,500 species); and reptiles and birds (with about 20,000 species divided evenly between the two classes). Tetrapods comprise the dominant megafauna of most terrestrial environments and also include many partially or fully aquatic groups (e.g., sea snakes, penguins, cetaceans).

Classification
There are several ways of classifying animals. Evolutionary systematics relies on anatomy, physiology and evolutionary history, which is determined through similarities in anatomy and, if possible, the genetics of organisms. Phylogenetic classification is based solely on phylogeny. Evolutionary systematics gives an overview; phylogenetic systematics gives detail. The two systems are thus complementary rather than opposed.

Traditional classification

Conventional classification has living vertebrates grouped into seven classes based on traditional interpretations of gross anatomical and physiological traits. This classification is the one most commonly encountered in school textbooks, overviews, non-specialist, and popular works. The extant vertebrates are:

 * Subphylum Vertebrata
 * Class Agnatha (jawless fishes)
 * Class Chondrichthyes (cartilaginous fishes)
 * Class Osteichthyes (bony fishes)
 * Class Amphibia (amphibians)
 * Class Reptilia (reptiles)
 * Class Aves (birds)
 * Class Mammalia (mammals)

In addition to these, there are two classes of extinct armoured fishes, the Placodermi and the Acanthodii, both considered paraphyletic.

Other ways of classifying the vertebrates have been devised, particularly with emphasis on the phylogeny of early amphibians and reptiles. An example based on Janvier (1981, 1997), Shu et al. (2003), and Benton (2004) is given here († = extinct):

 * Subphylum Vertebrata
 * Palaeospondylus
 * Infraphylum Agnatha or Cephalaspidomorphi (lampreys and other jawless fishes)
 * Superclass Anaspidomorphi (anaspids and relatives)
 * Infraphylum Gnathostomata (vertebrates with jaws)
 * Class Placodermi (extinct armoured fishes)
 * Class Chondrichthyes (cartilaginous fishes)
 * Class Acanthodii (extinct spiny "sharks")
 * Superclass Osteichthyes (bony vertebrates)
 * Class Actinopterygii (ray-finned bony fishes)
 * Class Sarcopterygii (lobe-finned fishes, including the tetrapods)
 * Superclass Tetrapoda (four-limbed vertebrates)
 * Class Amphibia (amphibians, some ancestral to the amniotes)—now a paraphyletic group
 * Class Synapsida (mammals and the extinct mammal-like reptiles)
 * Class Sauropsida (reptiles and birds)

While this traditional classification is orderly, most of the groups are paraphyletic, i.e. do not contain all descendants of the class's common ancestor. For instance, descendants of the first reptiles include modern reptiles, mammals and birds; the agnathans have given rise to the jawed vertebrates; the bony fishes have given rise to the land vertebrates; the traditional "amphibians" have given rise to the reptiles (traditionally including the synapsids or mammal-like "reptiles"), which in turn have given rise to the mammals and birds. Most scientists working with vertebrates use a classification based purely on phylogeny, organized by their known evolutionary history and sometimes disregarding the conventional interpretations of their anatomy and physiology.

Phylogenetic relationships
In phylogenetic taxonomy, the relationships between animals are not typically divided into ranks but illustrated as a nested "family tree" known as a phylogenetic tree. The cladogram below is based on studies compiled by Philippe Janvier and others for the Tree of Life Web Project and Delsuc et al., and complemented (based on, and ). A dagger (†) denotes an extinct clade, whereas all other clades have living descendants.

Note that, as shown in the cladogram above, the †"Ostracodermi" (armoured jawless fishes) and †"Placodermi" (armoured jawed fishes) are shown to be paraphylectic groups, separated from Gnathostomes and Eugnathostomes respectively.

Also note that Teleostei (Neopterygii) and Tetrapoda (amphibians, mammals, reptiles, birds) each make up about 50% of today's vertebrate diversity, while all other groups are either extinct or rare. The next cladogram shows the extant clades of tetrapods (the four-limbed vertebrates), and a selection of extinct (†) groups:

Note that reptile-like amphibians, mammal-like reptiles, and non-avian dinosaurs are all paraphyletic.

The placement of hagfish on the vertebrate tree of life has been controversial. Their lack of proper vertebrae (among with other characteristics found in lampreys and jawed vertebrates) led phylogenetic analyses based on morphology to place them outside Vertebrata. Molecular data, however, indicates they are vertebrates closely related to lampreys. A study by Miyashita et al. (2019), 'reconciliated' the two types of analysis as it supports the Cyclostomata hypothesis using only morphological data.

Number of extant species
The number of described vertebrate species are split between tetrapods and fish. The following table lists the number of described extant species for each vertebrate class as estimated in the IUCN Red List of Threatened Species, 2014.3.

The IUCN estimates that 1,305,075 extant invertebrate species have been described, which means that less than 5% of the described animal species in the world are vertebrates.

Vertebrate species databases
The following databases maintain (more or less) up-to-date lists of vertebrate species:
 * Fish: Fishbase
 * Amphibians: Amphibiaweb
 * Reptiles: Reptile Database
 * Birds: Avibase
 * Mammals: Mammal species of the World

Reproductive systems
Nearly all vertebrates undergo sexual reproduction. They produce haploid gametes by meiosis. The smaller, motile gametes are spermatozoa and the larger, non-motile gametes are ova. These fuse by the process of fertilisation to form diploid zygotes, which develop into new individuals.

Inbreeding
During sexual reproduction, mating with a close relative (inbreeding) often leads to inbreeding depression. Inbreeding depression is considered to be largely due to expression of deleterious recessive mutations. The effects of inbreeding have been studied in many vertebrate species.

In several species of fish, inbreeding was found to decrease reproductive success.

Inbreeding was observed to increase juvenile mortality in 11 small animal species.

A common breeding practice for pet dogs is mating between close relatives (e.g. between half- and full siblings). This practice generally has a negative effect on measures of reproductive success, including decreased litter size and puppy survival.

Incestuous matings in birds result in severe fitness costs due to inbreeding depression (e.g. reduction in hatchability of eggs and reduced progeny survival).

Inbreeding avoidance
As a result of the negative fitness consequences of inbreeding, vertebrate species have evolved mechanisms to avoid inbreeding.

Numerous inbreeding avoidance mechanisms operating prior to mating have been described. Toads and many other amphibians display breeding site fidelity. Individuals that return to natal ponds to breed will likely encounter siblings as potential mates. Although incest is possible, Bufo americanus siblings rarely mate. These toads likely recognize and actively avoid close kin as mates. Advertisement vocalizations by males appear to serve as cues by which females recognize their kin.

Inbreeding avoidance mechanisms can also operate subsequent to copulation. In guppies, a post-copulatory mechanism of inbreeding avoidance occurs based on competition between sperm of rival males for achieving fertilization. In competitions between sperm from an unrelated male and from a full sibling male, a significant bias in paternity towards the unrelated male was observed.

When female sand lizards mate with two or more males, sperm competition within the female's reproductive tract may occur. Active selection of sperm by females appears to occur in a manner that enhances female fitness. On the basis of this selective process, the sperm of males that are more distantly related to the female are preferentially used for fertilization, rather than the sperm of close relatives. This preference may enhance the fitness of progeny by reducing inbreeding depression.

Outcrossing
Mating with unrelated or distantly related members of the same species is generally thought to provide the advantage of masking deleterious recessive mutations in progeny (see heterosis). Vertebrates have evolved numerous diverse mechanisms for avoiding close inbreeding and promoting outcrossing (see inbreeding avoidance).

Outcrossing as a way of avoiding inbreeding depression has been especially well studied in birds. For instance, inbreeding depression occurs in the great tit (Parus major) when the offspring are produced as a result of a mating between close relatives. In natural populations of the great tit, inbreeding is avoided by dispersal of individuals from their birthplace, which reduces the chance of mating with a close relative.

Purple-crowned fairywren females paired with related males may undertake extra-pair matings that can reduce the negative effects of inbreeding, despite ecological and demographic constraints.

Southern pied babblers (Turdoides bicolor) appear to avoid inbreeding in two ways: through dispersal and by avoiding familiar group members as mates. Although both genders disperse locally, they move outside the range where genetically related individuals are likely to be encountered. Within their group, individuals only acquire breeding positions when the opposite-sex breeder is unrelated.

Cooperative breeding in birds typically occurs when offspring, usually males, delay dispersal from their natal group in order to remain with the family to help rear younger kin. Female offspring rarely stay at home, dispersing over distances that allow them to breed independently or to join unrelated groups.

Parthenogenesis
Parthenogenesis is a natural form of reproduction in which growth and development of embryos occur without fertilization.

Reproduction in squamate reptiles is ordinarily sexual, with males having a ZZ pair of sex determining chromosomes, and females a ZW pair. However, various species, including the Colombian Rainbow boa (Epicrates maurus), Agkistrodon contortrix (copperhead snake) and Agkistrodon piscivorus (cotton mouth snake) can also reproduce by facultative parthenogenesis—that is, they are capable of switching from a sexual mode of reproduction to an asexual mode—resulting in production of WW female progeny. The WW females are likely produced by terminal automixis.

Mole salamanders are an ancient (2.4–3.8 million year-old) unisexual vertebrate lineage. In the polyploid unisexual mole salamander females, a premeiotic endomitotic event doubles the number of chromosomes. As a result, the mature eggs produced subsequent to the two meiotic divisions have the same ploidy as the somatic cells of the female salamander. Synapsis and recombination during meiotic prophase I in these unisexual females is thought to ordinarily occur between identical sister chromosomes and occasionally between homologous chromosomes. Thus little, if any, genetic variation is produced. Recombination between homeologous chromosomes occurs only rarely, if at all. Since production of genetic variation is weak, at best, it is unlikely to provide a benefit sufficient to account for the long-term maintenance of meiosis in these organisms.

Self-fertilization
Two killifish species, the mangrove killifish (Kryptolebias marmoratus) and Kryptolebias hermaphroditus, are the only known vertebrates to self-fertilize. They produce eggs and sperm by meiosis and routinely reproduce by self-fertilisation. This capacity has apparently persisted for at least several hundred thousand years. Each individual hermaphrodite normally fertilizes itself through uniting inside the fish's body of an egg and a sperm that it has produced by an internal organ. In nature, this mode of reproduction can yield highly homozygous lines composed of individuals so genetically uniform as to be, in effect, identical to one another. Although inbreeding, especially in the extreme form of self-fertilization, is ordinarily regarded as detrimental because it leads to expression of deleterious recessive alleles, self-fertilization does provide the benefit of fertilization assurance (reproductive assurance) at each generation.

Population trends
The Living Planet Index, following 16,704 populations of 4,005 species of vertebrates, shows a decline of 60% between 1970 and 2014. Since 1970, freshwater species declined 83%, and tropical populations in South and Central America declined 89%. The authors note that, "An average trend in population change is not an average of total numbers of animals lost." According to WWF, this could lead to a sixth major extinction event. The five main causes of biodiversity loss are land-use change, overexploitation of natural resources, climate change, pollution and invasive species.

title: Vertebrate


text:
Thrace

Thrace (, ; Тракия; Θράκη; Trakya) is a geographical and historical region in Southeast Europe. Bounded by the Balkan Mountains to the north, the Aegean Sea to the south, and the Black Sea to the east, it comprises present-day southeastern Bulgaria (Northern Thrace), northeastern Greece (Western Thrace), and the European part of Turkey (East Thrace), roughly the Roman Province of Thrace. Lands also inhabited by ancient Thracians extended in the north to modern-day Northern Bulgaria and Romania and to the west into Macedonia.

Etymology
The word Thrace, from ancient Greek Thrake (Θρᾴκη), referred originally to the Thracians (ancient Greek Thrakes Θρᾷκες), an ancient people inhabiting Southeast Europe. The name Europe (ancient Greek Εὐρώπη), also at first referred to this region, before that term expanded to include its modern sense. The region could have been named after the principal river there, Hebros, possibly from the Indo-European arg "white river" (the opposite of Vardar, meaning "black river"), According to an alternative theory, Hebros means "goat" in Thracian.

According to Stephanus of Byzantium, long before the ancient Greeks started referring to the region as Thrace, it was known as Aria (Αρια) and Perki (Περκη).

In Turkey, it is commonly referred to as Rumeli, "Land of the Romans", which was the name traditionally given by Turkic societies to the Byzantine Empire and Orthodox Christians.

Mythology
In terms of ancient Greek mythology the name appears to derive from the heroine and sorceress Thrace, who was the daughter of Oceanus and Parthenope, and sister of Europa.

Borders
The historical boundaries of Thrace have varied. The ancient Greeks employed the term "Thrace" to refer to all of the territory which lay north of Thessaly inhabited by the Thracians, a region which "had no definite boundaries" and to which other regions (like Macedonia and even Scythia) were added. In one ancient Greek source, the very Earth is divided into "Asia, Libya, Europa and Thracia". As the Greeks gained knowledge of world geography, "Thrace" came to designate the area bordered by the Danube on the north, by the Euxine Sea (Black Sea) on the east, by northern Macedonia in the south, and by Illyria to the west. This largely coincided with the Thracian Odrysian kingdom, whose borders varied over time. After the Macedonian conquest, this region's former border with Macedonia was shifted from the Struma River to the Mesta River. This usage lasted until the Roman conquest. Henceforth, (classical) Thrace referred only to the tract of land largely covering the same extent of space as the modern geographical region. In its early period, the Roman province of Thrace was of this extent, but after the administrative reforms of the late 3rd century, Thracia's much reduced territory became the six small provinces which constituted the Diocese of Thrace. The medieval Byzantine theme of Thrace contained only what today is East Thrace.

Cities
The largest cities of Thrace are: Istanbul, Plovdiv, Çorlu, Tekirdağ, Burgas, Edirne, Stara Zagora, Sliven, Yambol, Haskovo, Komotini, Alexandroupoli, Xanthi, and Kırklareli.

Demographics and religion
Most of the Bulgarian and Greek population are Orthodox Christians, while most of the Turkish inhabitants of Thrace are Sunni Muslims.

Ancient Greek mythology
Ancient Greek mythology provides the Thracians with a mythical ancestor Thrax, the son of the war-god Ares, who was said to reside in Thrace. The Thracians appear in Homer's Iliad as Trojan allies, led by Acamas and Peiros. Later in the Iliad, Rhesus, another Thracian king, makes an appearance. Cisseus, father-in-law to the Trojan elder Antenor, is also given as a Thracian king.

Homeric Thrace was vaguely defined, and stretched from the River Axios in the west to the Hellespont and Black Sea in the east. The Catalogue of Ships mentions three separate contingents from Thrace: Thracians led by Acamas and Peiros, from Aenus; Cicones led by Euphemus, from southern Thrace, near Ismaros; and from the city of Sestus, on the Thracian (northern) side of the Hellespont, which formed part of the contingent led by Asius. Ancient Thrace was home to numerous other tribes, such as the Edones, Bisaltae, Cicones, and Bistones in addition to the tribe that Homer specifically calls the "Thracians".

Greek mythology is replete with Thracian kings, including Diomedes, Tereus, Lycurgus, Phineus, Tegyrius, Eumolpus, Polymnestor, Poltys, and Oeagrus (father of Orpheus).

Thrace is mentioned in Ovid's Metamorphoses, in the episode of Philomela, Procne, and Tereus: Tereus, the King of Thrace, lusts after his sister-in-law, Philomela. He kidnaps her, holds her captive, rapes her, and cuts out her tongue. Philomela manages to get free, however. She and her sister, Procne, plot to get revenge, by killing her son Itys (by Tereus) and serving him to his father for dinner. At the end of the myth, all three turn into birds – Procne into a swallow, Philomela into a nightingale, and Tereus into a hoopoe.

The city of Dicaea in Thrace was named after the son of Poseidon, Dicaeus.

Ancient and Roman history
Indigenous Thracians were divided into numerous tribes. The first to take greater control of Thrace, in part or whole, were the Achaemenian Persians in the late 6th century BC. The region was incorporated into their empire as the Satrapy of Skudra, after the Scythian campaign of Darius the Great. Thracian soldiers were used in Persian armies and are depicted in carvings of the Persepolis and Naqsh-e Rostam. Persians' presence in Thracia lasted for more than a century, ending with the conquests in the 4th century BC by Alexander the Great of Macedon, who divided the vast realm between his generals. Notably, Thracian troops are known to have accompanied Alexander when he crossed the Hellespont which abuts Thrace, during the invasion of the Persian Empire itself.

The Thracians recorded no collective name for themselves; terms such as Thrace and Thracians were assigned by the Greeks.

Divided into separate tribes, the Thracians did not form any lasting political organizations until the founding of the Odrysian state in the 4th century BC. Like Illyrians, the locally ruled Thracian tribes of the mountainous regions maintained a warrior tradition, while the tribes based in the plains were purportedly more peaceable. Recently discovered funeral mounds in Bulgaria suggest that Thracian kings did rule regions of Thrace with distinct Thracian national identity.

During this period, a subculture of celibate ascetics called the Ctistae lived in Thrace, where they served as philosophers, priests, and prophets.

Sections of Thrace particularly in the south started to become hellenized before the Peloponnesian War as Athenian and Ionian colonies were set up in Thrace before the war. Spartan and other Doric colonists followed them after the war. The special interest of Athens to Thrace is underlined by the numerous finds of Athenian silverware in Thracian tombs. In 168 BC, after the Third Macedonian war and the subjugation of Macedonia to the Romans, Thrace also lost its independence and became tributary to Rome. Towards the end of the 1st century BC Thrace lost its status as a client kingdom as the Romans began to directly appoint their kings. This situation lasted until 46 AD, when the Romans finally turned Thrace into a Roman province (Romana provincia Thracia).

During the Roman domination, within the geographical borders of ancient Thrace, there were two separate Roman provinces, namely Thrace ("provincia Thracia") and Lower Moesia ("Moesia inferior"). Later, in the times of Diocletian, the two provinces were joined and formed the so-called "Dioecesis Thracia". The establishment of Roman colonies and mostly several Greek cities, as was Nicopolis, Topeiros, Traianoupolis, Plotinoupolis, and Hadrianoupolis resulted from the Roman Empire's urbanization. The Roman provincial policy in Thrace favored mainly not the Romanization but the Hellenization of the country, which had started as early as the Archaic period through the Greek colonisation and was completed by the end of Roman antiquity. As regards the competition between the Greek and Latin language, the very high rate of Greek inscriptions in Thrace extending south of Haemus Mountains proves the complete language Hellenization of this region. The boundaries between the Greek and Latin speaking Thrace are placed just above the northern foothills of Haemus Mountains.

During the imperial period many Thracians – particularly members of the local aristocracy of the cities – had been granted the right of the Roman citizenship (civitas Romana) with all its privileges. Epigraphic evidence show a large increase in such naturalizations in the times of Trajan and Hadrian, while in 212 AD the emperor Caracalla granted, with his well-known decree (constitutio Antoniniana), the Roman citizenship to all the free inhabitants of the Roman Empire. During the same period (in the 1st-2nd century AD), a remarkable presence of Thracians is testified by the inscriptions outside the borders (extra fines) both in the Greek territory and in all the Roman provinces, especially in the provinces of Eastern Roman Empire.

Medieval history
By the mid-5th century, as the Western Roman Empire began to crumble, Thracia fell from the authority of Rome and into the hands of Germanic tribal rulers. With the fall of the Western Roman Empire, Thracia turned into a battleground territory for the better part of the next 1,000 years. The surviving eastern portion of the Roman Empire in the Balkans, later known as the Byzantine Empire, retained control over Thrace until the 7th century when the northern half of the entire region was incorporated into the First Bulgarian Empire and the remainder was reorganized in the Thracian theme. The Empire regained the lost regions in the late 10th century until the Bulgarians regained control of the northern half at the end of the 12th century. Throughout the 13th century and the first half of the 14th century, the region was changing in the hands of the Bulgarian and the Byzantine Empire (excluding Constantinople). In 1265 the area suffered a Mongol raid from the Golden Horde, led by Nogai Khan, and between 1305 and 1307 was raided by the Catalan company.

Ottoman period
In 1352, the Ottoman Turks conducted their first incursion into the region subduing it completely within a matter of two decades and ruled it for five centuries in general peace. In 1821, several parts of Thrace, such as Lavara, Maroneia, Sozopolis, Aenos, Callipolis, and Samothraki rebelled during the Greek War of Independence.

Modern history
With the Congress of Berlin in 1878, Northern Thrace was incorporated into the semi-autonomous Ottoman province of Eastern Rumelia, which united with Bulgaria in 1885. The rest of Thrace was divided among Bulgaria, Turkey and Greece at the beginning of the 20th century, following the Balkan Wars, World War I and the Greco-Turkish War. In Summer 1934, up to 10,000 Jews were maltreated, bereaved, and then forced to quit the region (see 1934 Thrace pogroms). From Bulgaria and Romania between 1934 and 1938 a large wave of Muslims immigrants called Göçmenler went to East Thrace.

Today, Thracian is a geographical term used in Bulgaria, Turkey, and Greece.

Notable Thracians

 * Orpheus was, in Ancient Greek mythology, the chief representative of the art of song and playing the lyre.
 * Protagoras was a Greek philosopher from Abdera, Thrace (c. 490–420 BC.) An expert in rhetorics and subjects connected to virtue and political life, often regarded as the first sophist. He is known primarily for three claims: (1) that man is the measure of all things, often interpreted as a sort of moral relativism, (2) that he could make the "worse (or weaker) argument appear the better (or stronger)" (see Sophism), and (3) that one could not tell if the gods existed or not (see Agnosticism).
 * Herodicus was a Greek physician of the fifth century BC who is considered the founder of sports medicine. He is believed to have been one of Hippocrates' tutors.
 * Democritus was a Greek philosopher and mathematician from Abdera, Thrace (c. 460–370 BC.) His main contribution is the atomic theory, the belief that all matter is made up of various imperishable indivisible elements which he called atoms.
 * Spartacus was a Thracian who led a large slave uprising in what is now Italy in 73–71 BC. His army of escaped gladiators and slaves defeated several Roman legions in what is known as the Third Servile War.
 * A number of Roman emperors of the 3rd–5th century were of Thraco-Roman backgrounds (Maximinus Thrax, Licinius, Galerius, Aureolus, Leo the Thracian, etc.). These emperors were elevated via a military career (hence the resultant nickname for them, Barracks Emperor), from the condition of common soldiers in one of the Roman legions to the foremost positions of political power.

Legacy
The Trakiya Heights in Antarctica "are named after the historical region."

title: Thrace