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Evolution
The scientific theory according to which populations change gradually through a process of natural selection.
5,264 Questions
What must be true of traits that are passed down through generations?
Traits that are passed down through the generations must be either culturally or environmentally inculcated or genetically inherited (or some combination of these).
Evolutionary biology concerns itself with genetically inherited traits.
In the long term, for genetically inherited traits to continue to be passed down through the generations, they must be at least neutral with regard to reproductive fitness, or advantageous (i.e. they must not be subject to negative selection pressure)
Charles Robert Darwin
What does it mean when organisms evolve?
When organisms evolve, it means that they have undergone genetic changes over time that result in new characteristics or adaptations that allow them to better survive and reproduce in their environment. Evolution is driven by natural selection, mutations, genetic drift, and other factors that lead to changes in the genetic makeup of a population.
There is no such thing! The Bible states that God Created the earth in 7 days. Not a big bang hit the earth and everything was there.
The answer above is very Christian-centric, but here's an answer in a nutshell: Scientists can't prove that there was an evolution, but they cannot disprove it either. So evolution wasn't nessecary, if that's what you believe. You know what? This whole question is regarding YOUR personal beliefs.
What are the topics in macroevolution?
Topics in macroevolution include speciation (the process by which one species splits into two), extinction events, adaptive radiations (rapid diversification of a single lineage into many different species), phylogenetics (study of evolutionary relationships among species), and mass extinctions that have shaped the history of life on Earth.
Does variation occur in plants?
Much more morphological variation occurs in plants. Genetic variation is the big variation in plants because of polyploidy; this doubling, tripling and halving of chromosome number in the mating of two plants not only leads to great variation in genetic material, but also leads to great speciation in plants.
Did Huxley writes that the theory of evolution was by no means the sole product of Darwin?
Possible so, as the theory of evolution by natural selection, though his greatest product, was by no means Darwin's only production. Just before he died he produced a treatise on earthworms that is still relevant today.
What was the phrase that herbert Spencer coined from Darwin's theory of evolution?
" Survival of the fittest. "
Is there anybody that doesn't believe in evolution and isn't a christian?
Many Muslims and Orthodox Jews do not " believe " in evolution. Of course the truth does not need you belief to be true and something can be true whether you believe it or not.
I should re-word this question.
Is there an atheist that doesn't agree with evolution?
There may be an atheist that does not agree with evolutionary theory, but what difference would that make?
If there was someone out there I would like to hear his views on evolution.
Which of lamarcks ideas was later found to be incorrect?
The idea of acquired characteristics. For instance. The idea that a blacksmith, who would develop enormous muscles due to his trade, could pass these physical attributes on to his children.
How did the idea of evolution affect Americans' ideas about wealth?
They began to believe that wealth was a sign of "survival of the fittest."
What are the four stages of cultural evolution?
hunting and gathering, pastoralism and nomadism, agricultural, and finally a stage of commerce
When was Charles Darwin's theory of evolution first published?
On July 1st 1858 there was a joint reading of the theories put forward by both Charles Robert Darwin and Alfred Russel Wallace at the Linnaen Society in London.
November 24, 1859 is when Charles Robert Darwin published,
On the Origin of Species By Means of Natural Selection or the Preservation of Favored Races in the Struggle For Life
How tall were humans 1000 years ago?
European males were estimated to have measured about 1,83m (6 ft) some 40.000 years ago. About 10.000 years ago, climate change and the adoption of agriculture caused a reduction to about 1,62m (5ft4). 600 years ago, European males were about 1.65m in length, as the Little Ice Age hitting Europe and general poverty coincided. Since then, a steadily improving diet has allowed the average European male to grow to an average of 1.75m (5ft9).
Note that these figures are for European males only, and do not apply to women or humans from other descent.
Do penguins come under ratites?
I do not think so, as ratites have no keel and have a flat sternum. Ostriches are an example of this large flightless bird that could not fly even if it had large enough wings. No keel to anchor the flight muscles.
How does anatomy help us understand evolution?
Slight anatomical changes over significant amounts of time resulting in new species and adaptations is precisely what evolution is. Having a knowledge of certain anatomies allows for comparison. Take orangutan anatomy for example. It is extremely similar to human anatomy, but there are certain differences that tell us that humans are not descendants from orangutans. Also, the fossil record on which evolution evidence is so well based, relies largely on classifying anatomical characteristics.
How did the discovery of mungo man affect the theory of evolution?
Not at all. Though some anthropological conclusions may have been changed.
How did the continental shift theory affect evolution?
The ultimate allopatric ( geographic ) speciation. If you had a population of quite similar organisms in a area that split the population into two or more populations when continental drift occurred you would have different mutations and changing environments putting selective pressure on two or more populations now.
How did Lamarck think species evolve?
Lamarck's theory is that an organism can pass traits to their offspring that they have acquired in their lifetime. One example commonly used is that he felt giraffes acquired long necks because of generations of them stretching and trying to reach higher leaves on the tree. He thought that these stretched muscles would be passed down to their offspring. This has been proven wrong because this is not how evolution takes place. If you would cut off the tails of two mice and then breed them their offspring would not have short tails.
What evidence did Darwin use to present his case for evolution?
He said that as giraffe stretching out their necks get longer and longer
What were the main ideas of Darwin's theory?
1) A group of organisms tend to reproduce more offspring than the environment can support.
2) Most populations tend to remain fairly constant in size because of various population regulation mechanisms at work, e.g., density-dependent factors and density-independent factors regulating population size. The population comes into an equilibrium with its present environment. (See your notes.)
3) Competition takes place because so many individuals are introduced into an environment with limited resources. There is a "struggle for existence." Such a competitive struggle for existence usually includes being better adapted for obtaining the available resources in comparison to other individuals. Especially note that physical combat is not a very important part of this concept.
4) There exists variation among individuals within any species because genetic changes occasionally occur that modify the DNA structure of chromosomes.
5) Variations caused by gene mutations are usually either harmful or useless. However, over the course of time, beneficial mutations may occur. Individuals that inherit beneficial mutations or beneficial gene recombinations are better adapted to survive. This is where the phrase "survival of the fittest" comes in or the process of natural selection. Again note that such a competitive struggle for existence usually includes being better adapted for obtaining the available resources in comparison to other individuals and that physical combat is not a very important part of this concept.
6) In a changing environment, those organisms with favorable genetic variations survive. The surviving organisms then reproduce and transmit their DNA to their offspring. Over a long period of time ENTIRELY NEW SPECIES EVOLVE. Organisms that have successful genetic variations not only live longer but produce more offspring who also inherit the favorable adaptation.
Why might scientists disagree with each other about the history of evolution?
Though the basics are settled some questions still remain. One of the biggest arguments in evolution now is the argument of the exact evolutionary history of the human lineage, and its relationships to its closest relatives, past and present.
The discussion about specific phylogenies remains because the genetic evidence is, while more precise than any other line, not so accurate as to allow only one phylogeny for each assay.
Also, there remains plenty to discuss on the subjects of mechanisms. Drift, biased gene conversion, plenty other mechanisms affect evolution - but to what degree?
