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Evolution
The scientific theory according to which populations change gradually through a process of natural selection.
5,264 Questions
What is Kimuras Neutral Theory of Molecular Evolution?
Kimura (1968) • The vast majority of evolutionary changes at the molecular level are caused by random drift of selectively neutral mutants (not affecting fitness) ! The Molecular Clock.
What must true for two organisms to be considered the same species?
they can produce fertile offspring
Why natural selection acts on the phenotype rather than genotype?
natural selection is a passive prosess . the mechanism of some individuals to be selected more than others is because they fit their environment more. and phenotype shows the fitness .
What kind of Americans opposed Darwins theory of evolution and why did they do so?
We often debate the way a baseball should be thrown or that someone wrote in an article that the way to hold a gun when shooting is THIS way not THAT way.
The people who oppose the idea of evolution are those who take the Christian bible literally.
Creationism is a religious belief. It says that all life began all at once just a few thousand years ago and has not changed.
Evolution says no to that view point. The universe is billions of years old and that things changed slowly over time and organisms adapt to survive in those changing environments.
These two will never agree and creationism should be seen in a religious light.
What theory is survival of the fittest?
Be careful with this, it is usually misinterpreted as survival of fittest individuals.
Instead it is survival of fittest population via death of some individuals early.
Individuals never evolve, they are fixed genetic snapshots in the movie of life, they simply live or die. Populations evolve.
They probably have a recent common ancestor.
They are closely related , they share 97 % of genes approximately .
Both contain DNA
Are the reasons for changing the classifications of dogs and fungi the same?
Basically, yes. Reasons for reclassification are found in morphology, behaviour and genetic sequences. Dogs as well as fungi are subjects in all three fields of knowledge, so additional data in any of these fields, or new ways of analysis in any of these fields can lead to reclassification of a species.
How did Darwin come up with natural selection to explain the theory of evolution?
Most educated people in Europe and the Americas during the 19th century had their first full exposure to the concept of evolution through the writings of Charles Darwin . Clearly, he did not invent the idea. That happened long before he was born. However, he carried out the necessary research to conclusively document that evolution has occurred and then made the idea acceptable for scientists and the general public. This was not easy since the idea of evolution had been strongly associated with radical scientific and political views coming out of post-revolutionary France. These ideas were widely considered to be a threat to the established social and political order.Charles Darwin
1809-1882
Charles Darwin was born into a moderately wealthy family in Shrewsbury, England. His father, Robert, had the largest medical practice outside of London at the time and his mother, Susannah Wedgwood, was from a family of wealthy pottery manufacturers. She died when Charles was only 8 years old. Thereafter, he was raised mostly by his father and older sisters. Charles grew up in comparative luxury in a large house with servants. However, this was a socially very conservative time in England that set narrow limits on a young man's behavior and future possibilities. The constraints on women in Darwin's social class were even greater. Most were given only enough education to efficiently manage the homes of their future husbands and raise their children. Young men were expected to go to university in order to prepare themselves to become medical doctors, military officers, or clerics in the Church of England. Most other occupations were considered somewhat unsavory.
At his father's direction, Charles Darwin started university at 16 in Edinburgh, Scotland as a medical student. He showed little academic interest in medicine and was revolted by the brutality of surgery. He dropped out after two years of study in 1827. His father then sent him to Cambridge University in 1828 to study theology. It was there that his life's direction took a radical change. He became very interested in the scientific ideas of the geologist Adam Sedgwick and the naturalist John Henslow with whom he spent considerable time collecting specimens from the countryside around the university. At this time in his life, Darwin apparently rejected the concept of biological evolution, just as his mentors Sedgwick and Henslow did. However, Darwin had been exposed to the ideas of Lamarck about evolution earlier while he was a student in Edinburgh.
Following graduation from Cambridge in 1831 with a degree in theology, Darwin was clearly more interested in biology and geology than he was in a clerical career. Fortunately, John Henslow was able to help him secure a berth on a British Navy mapping expedition that was going around the world on what would ultimately become a nearly five year long voyage. Initially, Darwin's father refused to allow him to go but was eventually persuaded by Charles and even agreed to pay for his passage and for that of his man servant on the journey. They sailed two days after Christmas in 1831 aboard the survey ship H.M.S. Beagle with Darwin acting as an unpaid naturalist and gentleman companion for the aristocratic captain, Robert Fitzroy. Darwin was only 22 years old at the time. The Beagle was a compact 90 foot long ship with a crew of 74. There was little space, even for the captain. Darwin shared a cramped 10 X 11 foot cabin with two other men and their belongings. Because of the Beagle's design and small size, it was generally thought by naval men that it was ill suited for the rough seas it would encounter, especially at the southern tip of South America. Darwin frequently suffered from sea sickness on the voyage. Fortunately, he was able to spend most of the time on land exploring. In fact, he was at sea for only 18 months during the nearly 5 years of the expedition.
It was during the beginning of the voyage that Darwin read the early books of Charles Lyell and became convinced by his proof that uniformitarianism provided the correct understanding of the earth's geological history. This intellectual preparation along with his research on the voyage were critical in leading Darwin to accept evolution. Especially important to the development of this understanding was his 5 weeks long visit to the Galápagos Islands in the Eastern Pacific Ocean. It was there that he began to comprehend what causes plants and animals to evolve, but he apparently did not clearly formulate his views on this until 1837.
Why are yellow frogs most likely to be eaten in the forest?
well because they are tasty many say they taste like curry mixed with mint sauce and sainsburys hommake coke
What process selects against populations that are not fit to survive in their environment?
No process.
The selection process selects variant individuals against the immediate environment. You seem to be talking about group selection which is not established biological consensus. Individuals are selected while populations evolve. Natural selection is for individuals and you need to get this concept down correctly.
PS: Where do you people get these ill posed questions? Teachers?
How do wings of penguins and puffins demonstrate convergent evolution?
No. Both are birds and their wings are a derived trait common to all birds. The wings of penguins and bats display convergent evolution.
Why is mutation important to spectation?
Without mutation there can be no evolution. Without evolution there can be no speciation.
What happened at the Scopes trial and what made people refuse to believe in evolution?
The Scopes trial was about a teacher seeking to bring issues surrounding the teaching of evolution to the attention of a wider audience. Although he succeeded in this, he lost the trial itself and was fined $100.
The law challenged by Scopes was the Butler Act, explicitly prohibiting the teaching of science thought to conflict with scripture - ie. evolution. This law was instated by Tennessee governor Austin Peay, for the usual reasons. It wasn't until 1967 that this particular law was successfully challenged and subsequently repealed.
What are the six major stages of hospital evolution in the US?
Almshouse as primarily institutions of social welfare
Community owned private hospitals as charitable institutions supported by affluent donors.
Institution of medical practice and training serving the needs of all members of society and able to make a profit
Emergence of a relatively small number of physicians owned proprietary hospitals.
University based centers of medical research
Emergence of medical systems providing a large array of health services.
What are the main principles of the contingency theory?
The main principles of the contingency theory is that no organization, regardless of how big or organized it is, can come up with a proper predictor of what might happen in the future accurately which is why contingencies should always be put in place in case of catastrophic events.
What theories explain the evolution of gender and development?
First, it should be noted that the development of gender (sexual dimorphism) is a subject separate from that of the evolution of sexual reproduction. Sexual reproduction had already existed for a long time when the first sexually dimorphic species evolved. Sexual dimorphism, gender, is the situation wherein there exist distinct roles in the reproductive cycle, and morphologies associated with each role have diverged. One way that sexual dimorphism could have evolved is through the difference in size an number between male and female gametes. Males are typically able to produce gametes in prodigious numbers, while females usually produce far fewer and larger gametes. This makes males more redundant, in some cases leading to male competition over females, while females may have the "luxury" of "picking and choosing" from the redundantly available males. A difference in gender roles and associated morphology may follow from this.
This is one way for gender and sexual dimorphism to evolve, but not the only way.
Which development was most likely the cause of the other three?
We can not answer this without "which" and "the other three".
When related species become dissimilar as they evolve they are undergoing what type of evolution?
Divergent Evolution.
Definition of Diverge: to deviate from a set course or standard.
soource: google definitions
