The Last Universal Ancestor

Evolutionary processes give rise to diversity at every level of biological organisation, including the levels of species, individual organisms, and molecules.

Mr_c_Darwin

All life on Earth shares a common ancestor known as the last universal ancestor, which lived approximately 3.5–3.8 billion years ago, although a study in 2015 found “remains of biotic life” from 4.1 billion years ago in ancient rocks in Western Australia. According to one of the researchers, “If life arose relatively quickly on Earth … then it could be common in the universe.”

Repeated formation of new species (speciation), change within species (anagenesis), and loss of species (extinction) throughout the evolutionary history of life on Earth are demonstrated by shared sets of morphological and biochemical traits, including shared DNA sequences.

These shared traits are more similar among species that share a more recent common ancestor, and can be used to reconstruct a biological “tree of life” based on evolutionary relationships (phylogenetics), using both existing species and fossils.

charles darwin

The fossil record includes a progression from early biogenic graphite, to microbial mat fossils, to fossilized multicellular organisms. Existing patterns of biodiversity have been shaped both by speciation and by extinction. More than 99 percent of all species that ever lived on Earth are estimated to be extinct. Estimates of Earth’s current species range from 10 to 14 million, of which about 1.2 million have been documented.

 

In the mid-19th century, Charles Darwin formulated the scientific theory of evolution by natural selection, published in his book On the Origin of Species (1859). Evolution by natural selection is a process demonstrated by the observation that more offspring are produced than can possibly survive, along with three facts about populations:

1) traits vary among individuals with respect to morphology, physiology, and behaviour (phenotypic variation),

2) different traits confer different rates of survival and reproduction (differential fitness), and

3) traits can be passed from generation to generation (heritability of fitness). Thus, in successive generations members of a population are replaced by progeny of parents better adapted to survive and reproduce in the biophysical environment in which natural selection takes place.

This teleonomy is the quality whereby the process of natural selection creates and preserves traits that are seemingly fitted for the functional roles they perform. Natural selection is the only known cause of adaptation but not the only known cause of evolution. Other, nonadaptive causes of microevolution include mutation and genetic drift.

Blind_Watchmaker

Self Indulgent Arrogance

Is Religion Human Beings Biggest Arrogance? Or is having no Faith even worse?

Axiological, or constructive, atheism rejects the existence of gods in favor of a “higher absolute”, such as humanity. This form of atheism favors humanity as the absolute source of ethics and values, and permits individuals to resolve moral problems without resorting to God. Marx and Freud used this argument to convey messages of liberation, full-development, and unfettered happiness.

atheist-poster
Born to prejudice?

 

One of the most common criticisms of atheism has been to the contrary—that denying the existence of a god leads to moral relativism, leaving one with no moral or ethical foundation, or renders life meaningless and miserable. Blaise Pascal argued this view in his Pensées.

French philosopher Jean-Paul Sartre identified himself as a representative of an “atheist existentialism” concerned less with denying the existence of God than with establishing that “man needs … to find himself again and to understand that nothing can save him from himself, not even a valid proof of the existence of God.”

tn-atheism-omment
Athesim delusion?

Sartre said a corollary of his atheism was that “if God does not exist, there is at least one being in whom existence precedes essence, a being who exists before he can be defined by any concept, and … this being is man.”

The practical consequence of this atheism was described by Sartre as meaning that there are no a priori rules or absolute values that can be invoked to govern human conduct, and that humans are “condemned” to invent these for themselves, making “man” absolutely “responsible for everything he does”.

 

Wallace I Salute You

I am reading all things Darwinism at the moment and I would just like to give Wallace a mention.

He was considered the 19th century’s leading expert on the geographical distribution of animal species and is sometimes called the “father of biogeography“.

More..

Wallace was one of the leading evolutionary thinkers of the 19th century and made many other contributions to the development of evolutionary theory besides being co-discoverer of natural selection. These included the concept of warning colouration in animals, and the Wallace effect, a hypothesis on how natural selection could contribute to speciation by encouraging the development of barriers against hybridisation.

Wallace-Alfred-portrait

The Starry Messenger

Galileo

The Galileo affair was a sequence of events, beginning around 1610, culminating with the trial and condemnation of Galileo Galilei by the Roman Catholic Inquisition in 1616 and 1633 for his support of heliocentrism.

In 1610, Galileo published his Sidereus Nuncius (Starry Messenger), describing the surprising observations that he had made with the new telescope, namely the phases of Venus and the Galilean moons of Jupiter. With these observations he promoted the heliocentric theory of Nicolaus Copernicus (published in De revolutionibus orbium coelestium in 1543). Galileo’s initial discoveries were met with opposition within the Catholic Church, and in 1616 the Inquisition declared heliocentrism to be formally heretical. Heliocentric books were banned and Galileo was ordered to refrain from holding, teaching or defending heliocentric ideas.

Galileo went on to propose a theory of tides in 1616, and of comets in 1619; he argued that the tides were evidence for the motion of the Earth. In 1632 Galileo, now an old man, published his Dialogue Concerning the Two Chief World Systems, which implicitly defended heliocentrism, and was immensely popular. Responding to mounting controversy over theology, astronomy and philosophy, the Roman Inquisition tried Galileo in 1633 and found him “gravely suspect of heresy“, sentencing him to indefinite imprisonment. Galileo was kept under house arrest until his death in 1642.

Galileo began his telescopic observations in the later part of 1609, and by March 1610 was able to publish a small book, The Starry Messenger (Sidereus Nuncius), relating some discoveries that had not been dreamed of in the philosophy of the time: mountains on the Moon, lesser moons in orbit around Jupiter, and the resolution of what had been thought to be very cloudy masses in the sky (nebulae) into collections of stars too faint to see individually without a telescope. Other observations followed, including the phases of Venus and the existence of sunspots.

Galileo’s contributions caused difficulties for theologians and natural philosophers of the time, as they contradicted scientific and philosophical ideas based on those of Aristotle and Ptolemy and closely associated with the Catholic Church (despite their being pagans). In particular, Galileo’s observations of the phases of Venus, which showed it to circle the sun, and the observation of moons orbiting Jupiter, contradicted the geocentric model of Ptolemy and supported the Copernican model advanced by Galileo.

Jesuit astronomers, experts both in Church teachings, science, and in natural philosophy, were at first skeptical and hostile to the new ideas; however, within a year or two the availability of good telescopes enabled them to repeat the observations. In 1611, Galileo visited the Collegium Romanum in Rome, where the Jesuit astronomers by that time had repeated his observations. Christoph Grienberger, one of the Jesuit scholars on the faculty, sympathized with Galileo’s theories, but was asked to defend the Aristotelian viewpoint by Claudio Acquaviva, the Father General of the Jesuits. Not all of Galileo’s claims were completely accepted: Christopher Clavius, the most distinguished astronomer of his age, never was reconciled to the idea of mountains on the Moon, and outside the collegium many still disputed the reality of the observations. In a letter to Kepler of August 1610, Galileo complained that some of the philosophers who opposed his discoveries had refused even to look through a telescope:

My dear Kepler, I wish that we might laugh at the remarkable stupidity of the common herd. What do you have to say about the principal philosophers of this academy who are filled with the stubbornness of an asp and do not want to look at either the planets, the moon or the telescope, even though I have freely and deliberately offered them the opportunity a thousand times? Truly, just as the asp stops its ears, so do these philosophers shut their eyes to the light of truth.

Geocentrists who did verify and accept Galileo’s findings had an alternative to Ptolemy’s model in an alternative geocentric (or “geo-heliocentric”) model proposed some decades earlier by Tycho Brahe—a model, in which, for example, Venus circled the sun.

Galileo became involved in a dispute over priority in the discovery of sunspots with Christoph Scheiner, a Jesuit. This became a bitter lifelong feud. Neither of them, however, was the first to recognise sunspots—the Chinese had already been familiar with them for centuries.

At this time, Galileo also engaged in a dispute over the reasons that objects float or sink in water, siding with Archimedes against Aristotle. The debate was unfriendly, and Galileo’s blunt and sometimes sarcastic style, though not extraordinary in academic debates of the time, made him enemies. During this controversy one of Galileo’s friends, the painter, Lodovico Cardi da Cigoli, informed him that a group of malicious opponents, which Cigoli subsequently referred to derisively as “the Pigeon league,” was plotting to cause him trouble over the motion of the earth, or anything else that would serve the purpose. According to Cigoli, one of the plotters had asked a priest to denounce Galileo’s views from the pulpit, but the latter had refused. Nevertheless, three years later another priest, Tommaso Caccini, did in fact do precisely that.

Means of Natural Selection

Selimiye_Camii_ve_Mavi_Gökyüzü
Coleyartastro – Sun over Religion.

 

Darwin’s Re:Evolution is natural…

 

It presented a body of evidence that the diversity of life arose by common descent through a branching pattern of evolution. Darwin included evidence that he had gathered on the Beagle expedition in the 1830s and his subsequent findings from research, correspondence, and experimentation.

 

Evolved?

 

Darwin’s book introduced the scientific theory that populations evolve over the  course of generations through a process of natural selection.

 

Continue reading “Means of Natural Selection”

Darwinism

Darwinism originally included the broad concepts of transmutation of species or of evolution which gained general scientific acceptance when Charles Darwin published On the Origin of Species, including concepts which predated Darwin’s theories, but subsequently referred to specific concepts of natural selection, the Weismann barrier or in genetics the central dogma of molecular biology.

Mr_c_Darwin
Charles Darwin of Darwinisim

Though it usually refers strictly to biological evolution, the term has been used by creationists to refer to the origin of life, and has even been applied to concepts of cosmic evolution, both fields which have no connection to Darwin’s work. It is therefore considered the belief and acceptance of Darwin’s, and his predecessors, work in place of other theories including divine design and extra-terrestrial origins.
The meaning of “Darwinism” has changed over time, and varies depending on its context. In the United States, the term “Darwinism” is often used by creationists as a pejorativeterm in reference to beliefs such as atheistic naturalism, but in the United Kingdom the term has no negative connotations, being freely used as a shorthand for the body of theory dealing with evolution, and in particular, evolution by natural selection.
The term was coined by Thomas Henry Huxley in April 1860, and was used to describe evolutionary concepts in general, including earlier concepts such as Spencerism. Many of the proponents of Darwinism at that time, including Huxley, had reservations about the significance of natural selection, and Darwin himself gave credence to what was later called Lamarckism.

Darwinism of August Weismann gained few supporters in the late 19th century. During this period, which has been called “the eclipse of Darwinism”, scientists proposed various alternative evolutionary mechanisms which eventually proved untenable. The development of the modern evolutionary synthesis from the 1930s to the1950s, incorporating natural selection with population genetics and Mendelian genetics, revived Darwinism in an updated form.
While the term has remained in use amongst scientific authors when referring to modern evolutionary theory, it has increasingly been argued that it is an inappropriate term for modern evolutionary theory. For example, Darwin was unfamiliar with the work of Gregor Mendel, and as a result had only a vague and inaccurate understanding of heredity. He naturally had no inkling of yet more recent developments and, like Mendel himself, knew nothing of genetic drift for example.