Search This Blog

Tuesday, October 30, 2018

Clash of Civilizations

From Wikipedia, the free encyclopedia

The Clash of Civilizations and the Remaking of World Order
Clash civilizations.jpg
Author Samuel P. Huntington
Publisher Simon & Schuster
Publication date
1997
ISBN 978-0-684-84441-1
OCLC 38269418

The Clash of Civilizations is a hypothesis that people's cultural and religious identities will be the primary source of conflict in the post-Cold War world. The American political scientist Samuel P. Huntington argued that future wars would be fought not between countries, but between cultures, and that Islamic extremism would become the biggest threat to world peace. It was proposed in a 1992 lecture at the American Enterprise Institute, which was then developed in a 1993 Foreign Affairs article titled "The Clash of Civilizations?", in response to his former student Francis Fukuyama's 1992 book, The End of History and the Last Man. Huntington later expanded his thesis in a 1996 book The Clash of Civilizations and the Remaking of World Order.

The phrase itself was earlier used by Albert Camus in 1946, by Girilal Jain in his analysis of the Ayodhya dispute in 1988, by Bernard Lewis in an article in the September 1990 issue of The Atlantic Monthly titled "The Roots of Muslim Rage" and by Mahdi El Mandjra in his book "La première guerre civilisationnelle" published in 1992. Even earlier, the phrase appears in a 1926 book regarding the Middle East by Basil Mathews: Young Islam on Trek: A Study in the Clash of Civilizations (p. 196). This expression derives from "clash of cultures", already used during the colonial period and the Belle Époque.

Huntington began his thinking by surveying the diverse theories about the nature of global politics in the post-Cold War period. Some theorists and writers argued that human rights, liberal democracy, and the capitalist free market economy had become the only remaining ideological alternative for nations in the post-Cold War world. Specifically, Francis Fukuyama argued that the world had reached the 'end of history' in a Hegelian sense.

Huntington believed that while the age of ideology had ended, the world had only reverted to a normal state of affairs characterized by cultural conflict. In his thesis, he argued that the primary axis of conflict in the future will be along cultural lines. As an extension, he posits that the concept of different civilizations, as the highest rank of cultural identity, will become increasingly useful in analyzing the potential for conflict. At the end of his 1993 Foreign Affairs article, "The Clash of Civilizations?", Huntington writes, "This is not to advocate the desirability of conflicts between civilizations. It is to set forth descriptive hypothesis as to what the future may be like."

In addition, the clash of civilizations, for Huntington, represents a development of history. In the past, world history was mainly about the struggles between monarchs, nations and ideologies, such as seen within Western civilization. But after the end of the Cold War, world politics moved into a new phase, in which non-Western civilizations are no longer the exploited recipients of Western civilization but have become additional important actors joining the West to shape and move world history.

Major civilizations according to Huntington

The clash of civilizations according to Huntington (1996),
 as presented in the book. Huntington divided the world into
the "major civilizations" in his thesis as such:

Huntington's thesis of civilizational clash

Huntington at the 2004 World Economic Forum

Huntington argues that the trends of global conflict after the end of the Cold War are increasingly appearing at these civilizational divisions. Wars such as those following the break up of Yugoslavia, in Chechnya, and between India and Pakistan were cited as evidence of inter-civilizational conflict. He also argues that the widespread Western belief in the universality of the West's values and political systems is naïve and that continued insistence on democratization and such "universal" norms will only further antagonize other civilizations. Huntington sees the West as reluctant to accept this because it built the international system, wrote its laws, and gave it substance in the form of the United Nations.

Huntington identifies a major shift of economic, military, and political power from the West to the other civilizations of the world, most significantly to what he identifies as the two "challenger civilizations", Sinic and Islam.

In Huntington's view, East Asian Sinic civilization is culturally asserting itself and its values relative to the West due to its rapid economic growth. Specifically, he believes that China's goals are to reassert itself as the regional hegemon, and that other countries in the region will 'bandwagon' with China due to the history of hierarchical command structures implicit in the Confucian Sinic civilization, as opposed to the individualism and pluralism valued in the West. Regional powers such as the two Koreas and Vietnam will acquiesce to Chinese demands and become more supportive of China rather than attempting to oppose it. Huntington therefore believes that the rise of China poses one of the most significant problems and the most powerful long-term threat to the West, as Chinese cultural assertion clashes with the American desire for the lack of a regional hegemony in East Asia.

Huntington argues that the Islamic civilization has experienced a massive population explosion which is fueling instability both on the borders of Islam and in its interior, where fundamentalist movements are becoming increasingly popular. Manifestations of what he terms the "Islamic Resurgence" include the 1979 Iranian revolution and the first Gulf War. Perhaps the most controversial statement Huntington made in the Foreign Affairs article was that "Islam has bloody borders". Huntington believes this to be a real consequence of several factors, including the previously mentioned Muslim youth bulge and population growth and Islamic proximity to many civilizations including Sinic, Orthodox, Western, and African.

Huntington sees Islamic civilization as a potential ally to China, both having more revisionist goals and sharing common conflicts with other civilizations, especially the West. Specifically, he identifies common Chinese and Islamic interests in the areas of weapons proliferation, human rights, and democracy that conflict with those of the West, and feels that these are areas in which the two civilizations will cooperate.

Russia, Japan, and India are what Huntington terms 'swing civilizations' and may favor either side. Russia, for example, clashes with the many Muslim ethnic groups on its southern border (such as Chechnya) but—according to Huntington—cooperates with Iran to avoid further Muslim-Orthodox violence in Southern Russia, and to help continue the flow of oil. Huntington argues that a "Sino-Islamic connection" is emerging in which China will cooperate more closely with Iran, Pakistan, and other states to augment its international position.

Huntington also argues that civilizational conflicts are "particularly prevalent between Muslims and non-Muslims", identifying the "bloody borders" between Islamic and non-Islamic civilizations. This conflict dates back as far as the initial thrust of Islam into Europe, its eventual expulsion in the Iberian reconquest, the attacks of the Ottoman Turks on Eastern Europe and Vienna, and the European imperial division of the Islamic nations in the 1800s and 1900s.

Huntington also believes that some of the factors contributing to this conflict are that both Christianity (upon which Western civilization is based) and Islam are:
  • Missionary religions, seeking conversion of others
  • Universal, "all-or-nothing" religions, in the sense that it is believed by both sides that only their faith is the correct one
  • Teleological religions, that is, that their values and beliefs represent the goals of existence and purpose in human existence.
More recent factors contributing to a Western–Islamic clash, Huntington wrote, are the Islamic Resurgence and demographic explosion in Islam, coupled with the values of Western universalism—that is, the view that all civilizations should adopt Western values—that infuriate Islamic fundamentalists. All these historical and modern factors combined, Huntington wrote briefly in his Foreign Affairs article and in much more detail in his 1996 book, would lead to a bloody clash between the Islamic and Western civilizations.

Why civilizations will clash

Huntington offers six explanations for why civilizations will clash:
  1. Differences among civilizations are too basic in that civilizations are differentiated from each other by history, language, culture, tradition, and, most importantly, religion. These fundamental differences are the product of centuries and the foundations of different civilizations, meaning they will not be gone soon.
  2. The world is becoming a smaller place. As a result, interactions across the world are increasing, which intensify "civilization consciousness" and the awareness of differences between civilizations and commonalities within civilizations.
  3. Due to economic modernization and social change, people are separated from longstanding local identities. Instead, religion has replaced this gap, which provides a basis for identity and commitment that transcends national boundaries and unites civilizations.
  4. The growth of civilization-consciousness is enhanced by the dual role of the West. On the one hand, the West is at a peak of power. At the same time, a return-to-the-roots phenomenon is occurring among non-Western civilizations. A West at the peak of its power confronts non-Western countries that increasingly have the desire, the will and the resources to shape the world in non-Western ways.
  5. Cultural characteristics and differences are less mutable and hence less easily compromised and resolved than political and economic ones.
  6. Economic regionalism is increasing. Successful economic regionalism will reinforce civilization-consciousness. Economic regionalism may succeed only when it is rooted in a common civilization.

The West versus the Rest

Huntington suggests that in the future the central axis of world politics tends to be the conflict between Western and non-Western civilizations, in [Stuart Hall]'s phrase, the conflict between "the West and the Rest". He offers three forms of general actions that non-Western civilization can take in response to Western countries.
  1. Non-Western countries can attempt to achieve isolation in order to preserve their own values and protect themselves from Western invasion. However, Huntington argues that the costs of this action are high and only a few states can pursue it.
  2. According to the theory of "band-wagoning" non-Western countries can join and accept Western values.
  3. Non-Western countries can make an effort to balance Western power through modernization. They can develop economic, military power and cooperate with other non-Western countries against the West while still preserving their own values and institutions. Huntington believes that the increasing power of non-Western civilizations in international society will make the West begin to develop a better understanding of the cultural fundamentals underlying other civilizations. Therefore, Western civilization will cease to be regarded as "universal" but different civilizations will learn to coexist and join to shape the future world.

Core state and fault line conflicts

In Huntington's view, intercivilizational conflict manifests itself in two forms: fault line conflicts and core state conflicts.

Fault line conflicts are on a local level and occur between adjacent states belonging to different civilizations or within states that are home to populations from different civilizations.
Core state conflicts are on a global level between the major states of different civilizations. Core state conflicts can arise out of fault line conflicts when core states become involved.

These conflicts may result from a number of causes, such as: relative influence or power (military or economic), discrimination against people from a different civilization, intervention to protect kinsmen in a different civilization, or different values and culture, particularly when one civilization attempts to impose its values on people of a different civilization.

Modernization, Westernization, and "torn countries"

Critics of Huntington's ideas often extend their criticisms to traditional cultures and internal reformers who wish to modernize without adopting the values and attitudes of Western culture. These critics sometimes claim that to modernize it is necessary to become Westernized to a very large extent, so that sources of tension with the West will be reduced.

Japan, China and the Four Asian Tigers have modernized in many respects while maintaining traditional or authoritarian societies which distinguish them from the West. Some of these countries have clashed with the West and some have not.

Perhaps the ultimate example of non-Western modernization is Russia, the core state of the Orthodox civilization. Huntington argues that Russia is primarily a non-Western state although he seems to agree that it shares a considerable amount of cultural ancestry with the modern West. According to Huntington, the West is distinguished from Orthodox Christian countries by its experience of the Renaissance, Reformation, the Enlightenment; by overseas colonialism rather than contiguous expansion and colonialism; and by the infusion of Classical culture through ancient Greece rather than through the continuous trajectory of the Byzantine Empire.

Huntington refers to countries that are seeking to affiliate with another civilization as "torn countries". Turkey, whose political leadership has systematically tried to Westernize the country since the 1920s, is his chief example. Turkey's history, culture, and traditions are derived from Islamic civilization, but Turkey's elite, beginning with Mustafa Kemal Atatürk who took power as first President in 1923, imposed Western institutions and dress, embraced the Latin alphabet, joined NATO, and has sought to join the European Union.

Mexico and Russia are also considered to be torn by Huntington. He also gives the example of Australia as a country torn between its Western civilizational heritage and its growing economic engagement with Asia.

According to Huntington, a torn country must meet three requirements to redefine its civilizational identity. Its political and economic elite must support the move. Second, the public must be willing to accept the redefinition. Third, the elites of the civilization that the torn country is trying to join must accept the country.

The book claims that to date no torn country has successfully redefined its civilizational identity, this mostly due to the elites of the 'host' civilization refusing to accept the torn country, though if Turkey gained membership in the European Union, it has been noted that many of its people would support Westernization, as in the following quote by EU Minister Egemen Bağış: "This is what Europe needs to do: they need to say that when Turkey fulfills all requirements, Turkey will become a member of the EU on date X. Then, we will regain the Turkish public opinion support in one day." If this were to happen, it would, according to Huntington, be the first to redefine its civilizational identity.

Criticism

Huntington has fallen under the stern critique of various left-leaning academic writers, who have either empirically, historically, logically, or ideologically challenged his claims (Fox, 2005; Mungiu Pippidi & Mindruta, 2002; Henderson & Tucker, 2001; Russett, Oneal, & Cox, 2000; Harvey, 2000).
In an article explicitly referring to Huntington, scholar Amartya Sen (1999) argues:
diversity is a feature of most cultures in the world. Western civilization is no exception. The practice of democracy that has won out in the modern West is largely a result of a consensus that has emerged since the Enlightenment and the Industrial Revolution, and particularly in the last century or so. To read in this a historical commitment of the West—over the millennia—to democracy, and then to contrast it with non-Western traditions (treating each as monolithic) would be a great mistake.
In his 2003 book Terror and Liberalism, Paul Berman argues that distinct cultural boundaries do not exist in the present day. He argues there is no "Islamic civilization" nor a "Western civilization", and that the evidence for a civilization clash is not convincing, especially when considering relationships such as that between the United States and Saudi Arabia. In addition, he cites the fact that many Islamic extremists spent a significant amount of time living or studying in the Western world. According to Berman, conflict arises because of philosophical beliefs various groups share (or do not share), regardless of cultural or religious identity.

Timothy Garton Ash objects to the ‘extreme cultural determinism… crude to the point of parody’ of Huntington’s idea that Catholic and Protestant Europe is headed for democracy but that Orthodox Christian and Islamic Europe must accept dictatorship.

Edward Said issued a response to Huntington's thesis in his 2001 article, "The Clash of Ignorance". Said argues that Huntington's categorization of the world's fixed "civilizations" omits the dynamic interdependency and interaction of culture. A longtime critic of the Huntingtonian paradigm, and an outspoken proponent of Arab issues, Edward Said (2004) also argues that the clash of civilizations thesis is an example of "the purest invidious racism, a sort of parody of Hitlerian science directed today against Arabs and Muslims" (p. 293).

Noam Chomsky has criticized the concept of the clash of civilizations as just being a new justification for the United States "for any atrocities that they wanted to carry out", which was required after the Cold War as the Soviet Union was no longer a viable threat.

Intermediate Region

Huntington's geopolitical model, especially the structures for North Africa and Eurasia, is largely derived from the "Intermediate Region" geopolitical model first formulated by Dimitri Kitsikis and published in 1978. The Intermediate Region, which spans the Adriatic Sea and the Indus River, is neither Western nor Eastern (at least, with respect to the Far East) but is considered distinct.Concerning this region, Huntington departs from Kitsikis contending that a civilizational fault line exists between the two dominant yet differing religions (Eastern Orthodoxy and Sunni Islam), hence a dynamic of external conflict. However, Kitsikis establishes an integrated civilization comprising these two peoples along with those belonging to the less dominant religions of Shia Islam, Alevism, and Judaism. They have a set of mutual cultural, social, economic and political views and norms which radically differ from those in the West and the Far East.In the Intermediate Region, therefore, one cannot speak of a civilizational clash or external conflict, but rather an internal conflict, not for cultural domination, but for political succession. This has been successfully demonstrated by documenting the rise of Christianity from the Hellenized Roman Empire, the rise of the Islamic caliphates from the Christianized Roman Empire and the rise of Ottoman rule from the Islamic caliphates and the Christianized Roman Empire.

Mohammad Khatami, reformist president of Iran (in office 1997–2005), introduced the theory of Dialogue Among Civilizations as a response to Huntington's theory.

Opposing concepts

In recent years, the theory of Dialogue Among Civilizations, a response to Huntington's Clash of Civilizations, has become the center of some international attention. The concept was originally coined by Austrian philosopher Hans Köchler in an essay on cultural identity (1972). In a letter to UNESCO, Köchler had earlier proposed that the cultural organization of the United Nations should take up the issue of a "dialogue between different civilizations" (dialogue entre les différentes civilisations). In 2001, Iranian president Mohammad Khatami introduced the concept at the global level. At his initiative, the United Nations proclaimed the year 2001 as the "United Nations Year of Dialogue among Civilizations".

The Alliance of Civilizations (AOC) initiative was proposed at the 59th General Assembly of the United Nations in 2005 by the Spanish Prime Minister, José Luis Rodríguez Zapatero and co-sponsored by the Turkish Prime Minister Recep Tayyip Erdoğan. The initiative is intended to galvanize collective action across diverse societies to combat extremism, to overcome cultural and social barriers between mainly the Western and predominantly Muslim worlds, and to reduce the tensions and polarization between societies which differ in religious and cultural values.

Geert Wilders, a Dutch politician best known for his intense criticism of Islam, has stated on several occasions that there is a clash between Western civilization and barbarism, referring to Islam.

Social effects of evolutionary theory

From Wikipedia, the free encyclopedia

The social effects of evolutionary thought have been considerable. As the scientific explanation of life's diversity has developed, it has often displaced alternative, sometimes very widely held, explanations. Because the theory of evolution includes an explanation of humanity's origins, it has had a profound impact on human societies. Some have vigorously denied acceptance of the scientific explanation due to its perceived religious implications (e.g. its implied rejection of the special creation of humans presumably described in the Bible). This has led to a vigorous conflict between creation and evolution in public education, primarily in the United States.

Evolution and ethics

The theory of evolution by natural selection has also been adopted as a foundation for various ethical and social systems, such as social Darwinism, an idea that preceded the publication of The Origin of Species, popular in the 19th century, which holds that "the survival of the fittest" (a phrase coined in 1851 by Herbert Spencer, 6 years before Darwin published his theory of evolution) explains and justifies differences in wealth and success among societies and people. A similar interpretation was one created by Darwin's cousin, Francis Galton, known as eugenics, which claimed that human civilization was subverting natural selection by allowing the less bright and less healthy to survive and out-breed the more smart and more healthy.

Later advocates of this theory suggested radical and often coercive social measures in an attempt to "correct" this imbalance. Thomas Huxley spent much time demonstrating through a series of thought experiments that it would not only be immoral, but impossible, Stephen Jay Gould and others have argued that social Darwinism is based on misconceptions of evolutionary theory, and many ethicists regard it as a case of the is-ought problem. After the atrocities of the Holocaust became linked with eugenics, it greatly fell out of favor with public and scientific opinion, though it was never universally accepted by either, and at no point in Nazi literature is Charles Darwin or the scientific theory of evolution mentioned.

In his book The End of Faith, Sam Harris argues that Nazism was largely a continuation of Christian anti-Semitism. Jim Walker compiled a list of 129 quotes from Mein Kampf in which Hitler described himself as a Christian, or mentioned God, Jesus or a biblical passage. Some argue that six million of the people killed during the Holocaust were killed because of their religion (Judaism) not their race, "strength," or any reason with an obvious link to the mechanism of Darwinian evolution. Hitler often used Christian beliefs like, "Jews killed Jesus," to justify his anti-Semitism.

The notion that humans share ancestors with other animals has also affected how some people view the relationship between humans and other species. Many proponents of animal rights hold that if animals and humans are of the same nature, then rights cannot be distinct to humans.

Charles Darwin, in fact, considered "sympathy" to be one of the most important moral virtues — and that it was, indeed, a product of natural selection and a trait beneficial to social animals (including humans). Darwin further argued that the most "sympathetic" societies would consequently be the most "successful." He also stated that our sympathy should be extended to "all sentient beings":
As man advances in civilization, and small tribes are united into larger communities, the simplest reason would tell each individual that he ought to extend his social instincts and sympathies to all the members of the same nation, though personally unknown to him. This point being once reached, there is only an artificial barrier to prevent his sympathies extending to the men of all nations and races. If, indeed, such men are separated from him by great differences in appearance or habits, experience unfortunately shows us how long it is, before we look at them as our fellow-creatures. ... This virtue, one of the noblest with which man is endowed, seems to arise incidentally from our sympathies becoming more tender and more widely diffused, until they are extended to all sentient beings. As soon as this virtue is honored and practiced by some few men, it spreads through instruction and example to the young, and eventually becomes incorporated in public opinion.
— Charles Darwin; The Descent of Man, 1871

Thomas Huxley: Evolution and Ethics

Thomas Huxley, Darwin's Bulldog, spent much of his book Evolution and Ethics debunking Social Darwinism, piece by piece. The following is a summary of his arguments in the Prolegomena, the most detailed and comprehensive of the two sections devoted to it. It should be noted that Huxley is here attempting to disprove the science behind Social Darwinism; as such, the moral arguments only come in later in the essay.

Consider a garden. Without constant upkeep, it would return to the state of nature, even the very walls surrounding it crumbling in sufficient time, but by constant diligence of the gardener, may be maintained in a state of art. This "state of art" is not permanent: It is instead the replacement of natural selection by artificial selection through the human energy expended in maintaining it.

This artificial selection is, however, part of natural selection: It is the action upon a set of species by the human species by way of the human species expending energy through evolved intelligence on its choice of selection. It is thus no less natural than, for example, a predator expending energy through evolved instinct on preferentially hunting a certain prey species. The presence of humans may change the dynamic, but in a perfectly natural way. Hence, it is part of the cosmic process, that is natural laws, even though the "histological process" may remove many aspects of the "struggle for existence" that is a key part of the natural laws that apply to biology, from its preferred plant species by substituting human work for work done by the species itself.
Not only is the state of nature hostile to the state of art of the garden; but the principle of the horticultural process, by which the latter is created and maintained, is antithetic to that of the cosmic process. The characteristic feature of the latter is the intense and unceasing competition of the struggle for existence. The characteristic of the former is the elimination of that struggle, by the removal of the conditions which give rise to it. The tendency of the cosmic process is to bring about the adjustment of the forms of plant life to the current conditions; the tendency of the horticultural process is the adjustment of the conditions to the needs of the forms of plant life which the gardener desires to raise.
Nature uses unrestricted breeding to let hundreds compete for the natural resources that would only support one, and uses frost and drought to kill off the weak and unlucky, requiring not just strength, but "flexibility and good fortune." However, a gardener restricts multiplication, gives each plant sufficient space and nourishment, protects from frost and drought—and, in every other way, attempts to modify the conditions to benefit the forms that most nearly approach the result he desires. However, though the gardener's actions may have circumvented natural selection, he can still improve the species, should he find them wanting, through selective breeding. The struggle for existence is not actually required for improvement: only heritability, variation, and some form of selective pressure.

Can we then apply this to humans? Let's see how far we can take the analogy with respect to colonization:
Suppose a shipload of English colonists sent to form a settlement, in such a country as Tasmania was in the middle of the last century. On landing, they find themselves in the midst of a state of nature, widely different from that left behind them in everything but the most general physical conditions. The common plants, the common birds and quadrupeds, are as totally distinct as the men from anything to be seen on the side of the globe from which they come. The colonists proceed to put an end to this state of things over as large an area as they desire to occupy. They clear away the native vegetation, extirpate or drive out the animal population, so far as may be necessary, and take measures to defend themselves from the re-immigration of either. In their place, they introduce English grain and fruit trees; English dogs, sheep, cattle, horses; and English men; in fact, they set up a new Flora and Fauna and a new variety of mankind, within the old state of nature. Their farms and pastures represent a garden on a great scale, and themselves the gardeners who have to keep it up, in watchful antagonism to the old regime. Considered as a whole, the colony is a composite unit introduced into the old state of nature; and, thenceforward, a competitor in the struggle for existence, to conquer or be vanquished.

Under the conditions supposed, there is no doubt of the result, if the work of the colonists be carried out energetically and with intelligent combination of all their forces. On the other hand, if they are slothful, stupid, and careless; or if they waste their energies in contests with one another, the chances are that the old state of nature will have the best of it. The native savage will destroy the immigrant civilized man; of the English animals and plants some will be extirpated by their indigenous rivals, others will pass into the feral state and themselves become components of the state of nature. In a few decades, all other traces of the settlement will have vanished.
However, as yet we lack an organized gardener. Let us imagine an idealized one: an administrative authority of intelligence and foresight as much greater than men as men are to their livestock. The unwanted native species - men, animals, or plants - are all weeded out and destroyed. Those to replace them are chosen with a view to his ideal of the colony, just as a gardener tries to create through his selection his ideal garden. And, finally, to ensure that no struggle for existence between the colonists interferes with the struggle against nature, he provides them with sufficient food, housing, and so on. "With every step of this progress in civilization, the colonists would become more and more independent of the state of nature; more and more, their lives would be conditioned by a state of art. In order to attain his ends, the administrator would have to avail himself of the courage, industry, and co-operative intelligence of the settlers; and it is plain that the interest of the community would be best served by increasing the proportion of persons who possess such qualities, and diminishing that of persons devoid of them. In other words, by selection directed towards an ideal."

However, though this might create a paradise where every aspect of nature works to support its colonists, problems arise: "as soon as the colonists began to multiply, the administrator would have to face the tendency to the reintroduction of the cosmic struggle into his artificial fabric, in consequence of the competition, not merely for the commodities, but for the means of existence. When the colony reached the limit of possible expansion, the surplus population must be disposed of somehow; or the fierce struggle for existence must recommence and destroy that peace, which is the fundamental condition of the maintenance of the state of art against the state of nature.

If the administrator is guided purely by scientific considerations, he would work to restrict the population by removing "the hopelessly diseased, the infirm aged, the weak or deformed in body or in mind, and the excess of infants born," just as a "gardener pulls up defective and superfluous plants, or the breeder destroys undesirable cattle. Only the strong and the healthy, carefully matched, with a view to the progeny best adapted to the purposes of the administrator, would be permitted to perpetuate their kind."

And so we have reached Social Darwinism. However, we do not have an idealized administrator:
Of the more thoroughgoing of the multitudinous attempts to apply the principles of cosmic evolution, or what are supposed to be such, to social and political problems, which have appeared of late years, a considerable proportion appear to me to be based upon the notion that human society is competent to furnish, from its own resources, an administrator of the kind I have imagined. The pigeons, in short, are to be their own Sir John Sebright. A despotic government, whether individual or collective, is to be endowed with the preternatural intelligence, and with what, I am afraid, many will consider the preternatural ruthlessness, required for the purpose of carrying out the principle of improvement by selection, with the somewhat drastic thoroughness upon which the success of the method depends. Experience certainly does not justify us in limiting the ruthlessness of individual "saviors of society"; and, on the well-known grounds of the aphorism which denies both body and soul to corporations, it seems probable (indeed the belief is not without support in history) that a collective despotism, a mob got to believe in its own divine right by demagogic missionaries, would be capable of more thorough work in this direction than any single tyrant, puffed up with the same illusion, has ever achieved. But intelligence is another affair. The fact that "saviors of society" take to that trade is evidence enough that they have none to spare. And such as they possess is generally sold to the capitalists of physical force on whose resources they depend. However, I doubt whether even the keenest judge of character, if he had before him a hundred boys and girls under fourteen, could pick out, with the least chance of success, those who should be kept, as certain to be serviceable members of the polity, and those who should be chloroformed, as equally sure to be stupid, idle, or vicious. The "points" of a good or of a bad citizen are really far harder to discern than those of a puppy or a short-horn calf; many do not show themselves before the practical difficulties of life stimulate manhood to full exertion. And by that time the mischief is done. The evil stock, if it be one, has had time to multiply, and selection is nullified.
However, humans are not cattle, nor flowers: the organization of human society is kept together by
...bonds of such a singular character, that the attempt to perfect society after his fashion would run serious risk of loosening them. They do not even correspond to social insects such as bees: With bees, "The members of the society are each organically predestined to the performance of one particular class of functions only. If they were endowed with desires, each could desire to perform none but those offices for which its organization specially fits it; and which, in view of the good of the whole, it is proper it should do. Among mankind, on the contrary, there is no such predestination to a sharply defined place in the social organism. However much men may differ in the quality of their intellects, the intensity of their passions, and the delicacy of their sensations, it cannot be said that one is fitted by his organization to be an agricultural laborer and nothing else, and another to be a landowner and nothing else. Moreover, with all their enormous differences in natural endowment, men agree in one thing, and that is their innate desire to enjoy the pleasures and to escape the pains of life; and, in short, to do nothing but that which it pleases them to do, without the least reference to the welfare of the society into which they are born, checked only by sympathy, familial and social bonds, and fear of the judgment of ones fellow man. "Every forward step of social progress brings men into closer relations with their fellows, and increases the importance of the pleasures and pains derived from sympathy.
In short, he describes a creation of morality.

Since morality is what keeps the desire for selfishness in check, it is necessary to the propagation of society, with one requirement: the punishment of wrongdoers being necessary for the continuation of society, self-restraint must not be taken so far that wrongdoers may act unrestrained: Without the protection of society against them, "The followers of the "golden rule" may indulge in hopes of heaven, but they must reckon with the certainty that other people will be masters of the earth."

Huxley sums up this section of his argument against Social Darwinism:
I have further shown cause for the belief that direct selection, after the fashion of the horticulturist and the breeder, neither has played, nor can play, any important part in the evolution of society; apart from other reasons, because I do not see how such selection could be practiced without a serious weakening, it may be the destruction, of the bonds which hold society together. It strikes me that men who are accustomed to contemplate the active or passive extirpation of the weak, the unfortunate, and the superfluous; who justify that conduct on the ground that it has the sanction of the cosmic process, and is the only way of ensuring the progress of the race; who, if they are consistent, must rank medicine among the black arts and count the physician a mischievous preserver of the unfit; on whose matrimonial undertakings the principles of the stud have the chief influence; whose whole lives, therefore, are an education in the noble art of suppressing natural affection and sympathy, are not likely to have any large stock of these commodities left. But, without them, there is no conscience, nor any restraint on the conduct of men, except the calculation of self-interest, the balancing of certain present gratifications against doubtful future pains; and experience tells us how much that is worth. Every day, we see firm believers in the hell of the theologians commit acts by which, as they believe when cool, they risk eternal punishment; while they hold back from those which are opposed to the sympathies of their associates.
Huxley finishes with a series of short, further evidences against Social Darwinism, including:
  • Historical evidences against: Consider the vast changes of society between the Tudor and the Victorian eras; however, human nature, as evidenced by their writing, remains the same. "In my belief, the innate qualities, physical, intellectual, and moral, of our nation have remained substantially the same for the last four or five centuries. If the struggle for existence has affected us to any serious extent (and I doubt it) it has been, indirectly, through our military and industrial wars with other nations."
  • Whether some qualities are virtues or vices depends on circumstance: "The benevolence and open-handed generosity which adorn a rich man, may make a pauper of a poor one; the energy and courage to which the successful soldier owes his rise, the cool and daring subtlety to which the great financier owes his fortune, may very easily, under unfavorable conditions, lead their possessors to the gallows, or to the hulks. Moreover, it is fairly probable that the children of a "failure" will receive from their other parent just that little modification of character which makes all the difference. I sometimes wonder whether people, who talk so freely about extirpating the unfit, ever dispassionately consider their own history. Surely, one must be very "fit," indeed, not to know of an occasion, or perhaps two, in one's life, when it would have been only too easy to qualify for a place among the "unfit.""
  • Evolution and Ethics at Project Gutenberg

Evolution and religion

Before Darwin's argument and presentation of the evidence for evolution, Western religions generally discounted or condemned any claims that diversity of life is the result of an evolutionary process, as did most scientists in the English scientific establishment. However, evolution was accepted by some religious groups such as the Unitarian church and the liberal Anglican theologians who went on to publish Essays and Reviews. as well as by many scientists in France and Scotland and some in England, notably Robert Edmund Grant. Literal or authoritative interpretations of Scripture hold that a supreme being directly created humans and other animals as separate Created kinds, which to some means species. This view is commonly referred to as creationism. From the 1920s to the present in the US, there has been a strong religious backlash to the teaching of evolution theory, particularly by conservative evangelicals. They have expressed concerns about the effects of the teaching of evolution on society and their faith (see Creation-evolution controversy).

In response to the wide scientific acceptance of the theory of evolution, many religions have formally or informally synthesized the scientific and religious viewpoints. Several important 20th century scientists (Fisher, Dobzhansky) whose work confirmed Darwin's theory, were also Christians who saw no incompatibility between their experimental and theoretical confirmations of evolution and their faith. Some religions have adopted a theistic evolution viewpoint, where God provides a divine spark that ignited the process of evolution and (or), where God has guided evolution in one way or another.

Evolution and the Roman Catholic Church

The Roman Catholic Church, beginning in 1950 with Pope Pius XII's encyclical Humani Generis, took up a neutral position with regard to evolution. "The Church does not forbid that...research and discussions, on the part of men experienced in both fields, take place with regard to the doctrine of evolution, in as far as it inquires into the origin of the human body as coming from pre-existent and living matter."

In an October 22, 1996, address to the Pontifical Academy of Science, Pope John Paul II updated the Church's position, recognizing that Evolution is "more than a hypothesis" - "In his encyclical Humani Generis, my predecessor Pius XII has already affirmed that there is no conflict between evolution and the doctrine of the faith regarding man and his vocation... Today, more than a half-century after the appearance of that encyclical, some new findings lead us toward the recognition of evolution as more than an hypothesis. In fact it is remarkable that this theory has had progressively greater influence on the spirit of researchers, following a series of discoveries in different scholarly disciplines."

Islamic views on Evolution

Classical figures have not discussed the subject as it has only come up in the 19th century. Contemporaries have come up with several distinct stances. One stance is that adaptation, or evolution on a micro scale, is accepted within a species, but cross-species evolution, that is evolution from one species into another species, is not as the human beginning is considered to be miraculous. However, this traditional thought would not conflict with the view that human-like beings could have been created around the same time as human beings, which, in this view, would explain the fossil records that look human but are not. Another stance is that since evolution is the simplest explanation it is the most reasonable to accept under the condition that it is not random but occurs only with the permission of God every step of the way. One particular argument that supports the idea that evolution is possible is the one stating that in that the stages of human development in evolution are akin to the distinct stages of development acknowledged in the Koran. The final stance completely rejects cross-species evolution across all organisms, but approves of adaptation (micro evolution).

Evolutionary theory and the political left

Many important political figures on the left have never publicized their views on biology, and so their opinions of evolutionary theory are unknown. To some extent, Marxists are the exception. Karl Marx, Friedrich Engels and Vladimir Lenin supported Darwin's evolutionary theory. Marx even sent Darwin a copy of his book Das Kapital, though Darwin never wrote back to him. Karl Marx's work was based on a material view of the world that showed natural causes and effects for all aspects of human society and economy. He recognized that Darwin's work provided a similar material explanation for all of nature, thus supporting Marx's worldview.

In 1861 Karl Marx wrote to his friend Ferdinand Lassalle, "Darwin’s work is most important and suits my purpose in that it provides a basis in natural science for the historical class struggle. ... Despite all shortcomings, it is here that, for the first time, 'teleology' in natural science is not only dealt a mortal blow but its rational meaning is empirically explained."

Most later Marxists agreed with this view, but some – particularly those in the early Soviet Union – believed that evolutionary theory conflicted with their economic and social ideals. As a result, they came to support Lamarckism instead – the idea that an organism can pass on characteristics that it acquired during its lifetime to its offspring. This led to the practice of Lysenkoism, which caused agricultural problems.

In his book, Mutual Aid: A Factor of Evolution, anarcho-communist Peter Kropotkin argued that co-operation and mutual aid are as important in the evolution of the species as competition and mutual strife, if not more so.

On the contemporary moderate left, some authors such as Peter Singer (in his book, A Darwinian Left) support Darwinism but reach different political and economic lessons than more conservative observers. Richard Dawkins' book, The Selfish Gene, has a chapter, "Nice guys finish first," that attempts to explain the role of altruism and cooperation in evolution and how social animals not only cannot survive without such traits, but how evolution will create them. Dawkins explains that when an animal sacrifices itself or uses its resources for the survival of other members of the same species, its genes, present on the other animals, survive. For example, if a mother dies to save three of its pups, one and a half copies (on average) of its genes will survive, because there is a 50% chance of a particular gene being present in its offspring. Dawkins also made a documentary of the same name. According to the documentary, Dawkins added that chapter as a way of overcoming modern day misinterpretations of the concept of survival of the fittest.

Evolution in relation to Social Darwinism and Imperialism

"Social Darwinism" is a derogatory term associated with the 19th century Malthusian theory developed by Whig philosopher Herbert Spencer. It is associated with evolutionary theory but now widely regarded as unwarranted. Social Darwinism was later expanded by others into ideas about "survival of the fittest" in commerce and human societies as a whole, and led to claims that social inequality, sexism, racism and imperialism were justified. However, these ideas contradict Darwin's own views, and contemporary scientists and philosophers consider these ideas to be neither mandated by evolutionary theory nor supported by data.

Social Darwinism is further linked with nationalism and imperialism. During the age of New Imperialism, the concepts of evolution justified the exploitation of "lesser breeds without the law" by "superior races." To elitists, strong nations were composed of white people who were successful at expanding their empires, and as such, these strong nations would survive in the struggle for dominance. With this attitude, Europeans, except for Christian missionaries, seldom adopted the customs and languages of local people under their empires. Christian missionaries, on the other hand, were the very first individuals to meet new peoples and develop writing systems for local inhabitants' languages that lacked one. Being critics of Darwinism, they ardently opposed slavery and provided an education and religious instruction to the new peoples they interacted with since they felt that this was their duty as Christians.

Adaptive radiation

From Wikipedia, the free encyclopedia

Four of the 14 finch species found in the Galápagos Archipelago, which are thought to have evolved via an adaptive radiation that diversified their beak shapes, enabling them to exploit different food sources.

In evolutionary biology, adaptive radiation is a process in which organisms diversify rapidly from an ancestral species into a multitude of new forms, particularly when a change in the environment makes new resources available, creates new challenges, or opens new environmental niches. Starting with a recent single ancestor, this process results in the speciation and phenotypic adaptation of an array of species exhibiting different morphological and physiological traits. The prototypical example of adaptive radiation is finch speciation on the Galapagos ("Darwin's finches"), but examples are known from around the world.

Characteristics

Four features can be used to identify an adaptive radiation:
  1. A common ancestry of component species: specifically a recent ancestry. Note that this is not the same as a monophyly in which all descendants of a common ancestor are included.
  2. A phenotype-environment correlation: a significant association between environments and the morphological and physiological traits used to exploit those environments.
  3. Trait utility: the performance or fitness advantages of trait values in their corresponding environments.
  4. Rapid speciation: presence of one or more bursts in the emergence of new species around the time that ecological and phenotypic divergence is underway.

Conditions

Adaptive radiation tends to take place under the following conditions:
  1. A new habitat has opened up: a volcano, for example, can create new ground in the middle of the ocean. This is the case in places like Hawaii and the Galapagos. For aquatic species, the formation of a large new lake habitat could serve the same purpose; the tectonic movement that formed the East African Rift, ultimately leading to the creation of the Rift Valley Lakes, is an example of this. An extinction event could effectively achieve this same result, opening up niches that were previously occupied by species that no longer exist.
  2. This new habitat is relatively isolated. When a volcano erupts on the mainland and destroys an adjacent forest, it is likely that the terrestrial plant and animal species that used to live in the destroyed region will recolonize without evolving greatly. However, if a newly formed habitat is isolated, the species that colonize it will likely be somewhat random and uncommon arrivals.
  3. The new habitat needs a wide availability of niche space. The rare colonist can only adaptively radiate into as many forms as there are niches.

Examples

Darwin's finches

Darwin's finches are an often-used textbook example of adaptive radiation. Today represented by approximately 15 species, Darwin's finches are Galapagos endemics famously adapted for a specialized feeding behavior (although one species, the Cocos finch (Pinaroloxias inornata), is not found in the Galapagos but on the island of Cocos south of Costa Rica). Darwin's finches are not actually finches in the true sense, but are members of the tanager family Thraupidae, and are derived from a single ancestor that arrived in the Galapagos from mainland South America perhaps just 3 million years ago. Excluding the Cocos finch, each species of Darwin's finch is generally widely distributed in the Galapagos and fills the same niche on each island. For the ground finches, this niche is a diet of seeds, and they have thick bills to facilitate the consumption of these hard materials. The ground finches are further specialized to eat seeds of a particular size: the large ground finch (Geospiza magnirostris) is the largest species of Darwin's finch and has the thickest beak for breaking open the toughest seeds, the small ground finch (Geospiza fuliginosa) has a smaller beak for eating smaller seeds, and the medium ground finch (Geospiza fortis) has a beak of intermediate size for optimal consumption of intermediately sized seeds (relative to G. magnirostris and G. fuliginosa). There is some overlap: for example, the most robust medium ground finches could have beaks larger than those of the smallest large ground finches. Because of this overlap, it can be difficult to tell the species apart by eye, though their songs differ. These three species often occur sympatrically, and during the rainy season in the Galapagos when food is plentiful, they specialize little and eat the same, easily accessible foods. It was not well-understood why their beaks were so adapted until Peter and Rosemary Grant studied their feeding behavior in the long dry season, and discovered that when food is scarce, the ground finches use their specialized beaks to eat the seeds that they are best suited to eat and thus avoid starvation.

The other finches in the Galapagos are similarly uniquely adapted for their particular niche. The cactus finches (Geospiza sp.) have somewhat longer beaks than the ground finches that serve the dual purpose of allowing them to feed on Opuntia cactus nectar and pollen while these plants are flowering, but on seeds during the rest of the year. The warbler-finches (Certhidea sp.) have short, pointed beaks for eating insects. The woodpecker finch (Camarhynchus pallidus) has a slender beak which it uses to pick at wood in search of insects; it also uses small sticks to reach insect prey inside the wood, making it one of the few animals that use tools.

The mechanism by which the finches initially diversified is still an area of active research. One proposition is that the finches were able to have a non-adaptive, allopatric speciation event on separate islands in the archipelago, such that when they reconverged on some islands they were able to maintain reproductive isolation. Once they occurred in sympatry, niche specialization was favored so that the different species competed less directly for resources. This second, sympatric event was adaptive radiation.

Cichlids of the African Great Lakes

The haplochromine cichlid fishes in the Great Lakes of the East African Rift (particularly in Lake Tanganyika, Lake Malawi, and Lake Victoria) form the most speciose modern example of adaptive radiation. These lakes are believed to be home to about 2,000 different species of cichlid, spanning a wide range of ecological roles and morphological characteristics. Cichlids in these lakes fill nearly all of the roles typically filled by a large number of fish families, including those of predators, scavengers, and herbivores, with varying dentitions and head shapes to match their dietary habits. In each case, the radiation events are only a few million years old, making the very high level of speciation particularly remarkable. Several factors could be responsible for this diversity: the availability of a multitude of niches probably favored specialization, as few other fish taxa are present in the lakes (meaning that sympatric speciation was the most probable mechanism for initial specialization). Also, continual changes in the water level of the lakes during the Pleistocene (which often turned the largest lakes into several smaller ones) could have created the conditions for secondary allopatric speciation.

Tanganyika cichlids

Lake Tanganyika is the site from which nearly all the cichlid lineages of East Africa (including both riverine and lake species) originated. Thus, the species in the lake constitute a single adaptive radiation event but do not form a single monophyletic clade. Lake Tanganyika is also the least speciose of the three largest African Great Lakes, with only around 200 species of cichlid; however, these cichlids are more morphologically divergent and ecologically distinct than their counterparts in lakes Malawi and Victoria, an artifact of Lake Tanganyika's older cichlid fauna. Lake Tanganyika itself is believed to have formed 9-12 million years ago, putting a recent cap on the age of the lake's cichlid fauna. Many of Tanganyika's cichlids live very specialized lifestyles. The giant or emperor cichlid (Boulengerochromis microlepis) is a piscivore often ranked the largest of all cichlids (though it competes for this title with South America's Cichla temensis, the speckled peacock bass). It is thought that giant cichlids spawn only a single time, breeding in their third year and defending their young until they reach a large size, before dying of starvation some time thereafter. The three species of Altolamprologus are also piscivores, but with laterally compressed bodies and thick scales enabling them to chase prey into thin cracks in rocks without damaging their skin. Plecodus straeleni has evolved large, strangely curved teeth that are designed to scrape scales off of the sides of other fish, scales being its main source of food. Gnathochromis permaxillaris possesses a large mouth with a protruding upper lip, and feeds by opening this mouth downward onto the sandy lake bottom, sucking in small invertebrates. A number of Tanganyika's cichlids are shell-brooders, meaning that mating pairs lay and fertilize their eggs inside of empty shells on the lake bottom. Lamprologus callipterus is the most unique egg-brooding species, with 15 cm-long males amassing collections of shells and guarding them in the hopes of attracting females (about 6 cm in length) to lay eggs in these shells. These dominant males must defend their territories from three types of rival: (1) other dominant males looking to steal shells; (2) younger, "sneaker" males looking to fertilize eggs in a dominant male's territory; and (3) tiny, 2–4 cm "parasitic dwarf" males that also attempt to rush in and fertilize eggs in the dominant male's territory. These parasitic dwarf males never grow to the size of dominant males, and the male offspring of dominant and parasitic dwarf males grow with 100% fidelity into the form of their fathers. A number of other highly specialized Tanganyika cichlids exist aside from these examples, including those adapted for life in open lake water up to 200m deep.

Malawi cichlids

The cichlids of Lake Malawi constitute a "species flock" of up to 1000 endemic species. Only seven cichlid species in Lake Malawi are not a part of the species flock: the Eastern happy (Astatotilapia calliptera), the sungwa (Serranochromis robustus), and five tilapia species (genera Oreochromis and Coptodon). All of the other cichlid species in the lake are descendants of a single original colonist species, which itself was descended from Tanganyikan ancestors. The common ancestor of Malawi's species flock is believed to have reached the lake 3.4 million years ago at the earliest, making Malawi cichlids' diversification into their present numbers particularly rapid. Malawi's cichlids span a similarly range of feeding behaviors to those of Tanganyika, but also show signs of a much more recent origin. For example, all members of the Malawi species flock are mouth-brooders, meaning the female keeps her eggs in her mouth until they hatch; in almost all species, the eggs are also fertilized in the female's mouth, and in a few species, the females continue to guard their fry in their mouth after they hatch. Males of most species display predominantly blue coloration when mating. However, a number of particularly divergent species are known from Malawi, including the piscivorous Nimbochromis livingtonii, which lies on its side in the substrate until small cichlids, perhaps drawn to its broken white patterning, come to inspect the predator - at which point they are swiftly eaten.

Victoria cichlids

Lake Victoria's cichlids are also a species flock, once composed of some 500 or more species. The deliberate introduction of the Nile Perch (Lates niloticus) in the 1950s proved disastrous for Victoria cichlids, and the collective biomass of the Victoria cichlid species flock has decreased substantially and an unknown number of species have become extinct. However, the original range of morphological and behavioral diversity seen in the lake's cichlid fauna is still mostly present today, if endangered. These again include cichlids specialized for niches across the trophic spectrum, as in Tanganyika and Malawi, but again, there are standouts. Victoria is famously home to a large number of piscivorous cichlid species, some of which feed by sucking the contents out of mouthbrooding females' mouths. Victoria's cichlids constitute a far younger radiation than even that of Lake Malawi, with estimates of the age of the flock ranging from 200,000 years to as little as 14,000.

Adaptive radiation in Hawaii

An ʻiʻiwi (Drepanis coccinea). Note the long, curved beak for sipping nectar from tubular flowers.

Hawaii has served as the site of a number of adaptive radiation events, owing to its isolation, recent origin, and large land area. The three most famous examples of these radiations are presented below, though insects like the Hawaiian drosophilid flies and Hyposmocoma moths have also undergone adaptive radiation.

Hawaiian honeycreepers

The Hawaiian honeycreepers form a large, highly morphologically diverse species group that began radiating in the early days of the Hawaiian archipelago. While today only 17 species are known to persist in Hawaii (3 more may or may not be extinct), there were more than 50 species prior to Polynesian colonization of the archipelago (between 18 and 21 species have gone extinct since the discovery of the islands by westerners). The Hawaiian honeycreepers are known for their beaks, which are specialized to satisfy a wide range of dietary needs: for example, the beak of the ʻakiapōlāʻau (Hemignathus wilsoni) is characterized by a short, sharp lower mandible for scraping bark off of trees, and the much longer, curved upper mandible is used to probe the wood underneath for insects. Meanwhile, the ʻiʻiwi (Drepanis coccinea) has a very long curved beak for reaching nectar deep in Lobelia flowers. An entire clade of Hawaiian honeycreepers, the tribe Psittirostrini, is composed of thick-billed, mostly seed-eating birds, like the Laysan finch (Telespiza cantans). In at least some cases, similar morphologies and behaviors appear to have evolved convergently among the Hawaiian honeycreepers; for example, the short, pointed beaks of Loxops and Oreomystis evolved separately despite once forming the justification for lumping the two genera together. The Hawaiian honeycreepers are believed to have descended from a single common ancestor some 15 to 20 million years ago, though estimates range as low as 3.5 million years.

Hawaiian silverswords

A mixture of blooming and non-blooming Haleakalā silverswords (Argyroxiphium sandwicense macrocephalum).

Adaptive radiation is not a strictly vertebrate phenomenon, and examples are also known from among plants. The most famous example of adaptive radiation in plants is quite possibly the Hawaiian silverswords, named for alpine desert-dwelling Argyroxiphium species with long, silvery leaves that live for up to 20 years before growing a single flowering stalk and then dying. The Hawaiian silversword alliance consists of twenty-eight species of Hawaiian plants which, aside from the namesake silverswords, includes trees, shrubs, vines, cushion plants, and more. The silversword alliance is believed to have originated in Hawaii no more than 6 million years ago, making this one of Hawaii's youngest adaptive radiation events. This means that the silverswords evolved on Hawaii's modern high islands, and descended from a single common ancestor that arrived on Kauai from western North America. The closest modern relatives of the silverswords today are California tarweeds of the family Asteraceae.

Hawaiian lobelioids

Hawaii is also the site of a separate major floral adaptive radiation event: the Hawaiian lobelioids. The Hawaiian lobelioids are significantly more speciose than the silverswords, perhaps because they have been present in Hawaii for so much longer: they descended from a single common ancestor who arrived in the archipelago up to 15 million years ago. Today the Hawaiian lobelioids form a clade of over 125 species, including succulents, trees, shrubs, epiphytes, etc. A large number of species have been lost to extinction and many of the surviving species endangered.

Caribbean anoles

Anole lizards are distributed broadly in the New World, from the Southeastern US to South America. With over 400 species currently recognized, often placed in a single genus (Anolis), they constitute one of the largest radiation events among all lizards. Anole radiation on the mainland has largely been a process of speciation, and is not adaptive to any great degree, but anoles on each of the Greater Antilles (Cuba, Hispaniola, Puerto Rico, and Jamaica) have adaptively radiated in separate, convergent ways. On each of these islands, anoles have evolved with such a consistent set of morphological adaptations that each species can be assigned to one of six "ecomorphs": trunk–ground, trunk–crown, grass–bush, crown–giant, twig, and trunk. Take, for example, crown–giants from each of these islands: the Cuban Anolis luteogularis, Hispaniola's Anolis ricordii, Puerto Rico's Anolis cuvieri, and Jamaica's Anolis garmani (Cuba and Hispaniola are both home to more than one species of crown–giant). These anoles are all large, canopy-dwelling species with large heads and large lamellae (scales on the undersides of the fingers and toes that are important for traction in climbing), and yet none of these species are particularly closely related and appear to have evolved these similar traits independently. The same can be said of the other five ecomorphs across the Caribbean's four largest islands. Much like in the case of the cichlids of the three largest African Great Lakes, each of these islands is home to its own convergent Anolis adaptive radiation event.

Other examples

Presented above are the most well-documented examples of modern adaptive radiation, but other examples are known. On Madagascar, birds of the family Vangidae are marked by very distinct beak shapes to suit their ecological roles. Madagascan mantellid frogs have radiated into forms that mirror other tropical frog faunas, with the brightly colored mantellas (Mantella) having evolved convergently with the Neotropical poison dart frogs of Dendrobatidae, while the arboreal Boophis species are the Madagascan equivalent of tree frogs and glass frogs. The pseudoxyrhophiine snakes of Madagascar have evolved into fossorial, arboreal, terrestrial, and semi-aquatic forms that converge with the colubroid faunas in the rest of the world. These Madagascan examples are significantly older than most of the other examples presented here: Madagascar's fauna has been evolving in isolation since the island split from India some 88 million years ago, and the Mantellidae originated around 50 mya. Older examples are known: the K-Pg extinction event, which caused the disappearance of the dinosaurs and most other reptilian megafauna 65 million years ago, is seen as having triggered a global adaptive radiation event that created the mammal diversity that exists today.

Spouse

From Wikipedia, the free encyclopedia ...