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Evolution

The scientific theory according to which populations change gradually through a process of natural selection.

5,264 Questions

How does the process of fertilization act to increase genetic diversity within a population?

Random fertilization. All the eggs and sperm produced are variations due to crossing over alone, not even considering other processes. The meet and fertilization occurs randomly insuring a good mix of genetic variation. Thus, genetic diversity.

What is capable of evolution?

Evolution is a process in which something passes by degrees to a different stage, especially a more advanced or mature stage. In biology it is the sequence of events involved in the evolutionary development of a change in a species. All living things are capable of evolution.

Why was the evolution of nucleic acids important to the evolution of protocells?

Nucleic acids have a number of important features. They are self replicating, and they also have the capacity to synthesize proteins. These proteins, in turn, can regulate or cause all other biochemical processes involved in life. So nucleic acids become the means to store information about how any organism functions, and to bring about those functions as needed.

True of False As a result of hundreds of thousands of years of natural selection modern humans are now perfectly adapted to their environment?

False. Organisms are never ' perfectly adapted to the environment, as evolution is blind and can not predict the future, or create anew. All is ' tinkered ' together in the organism on top of adaptions that were from past environments. Natural selection adapts as best it can to the immediate environment and carries vestigial traits and poor engineering solutions on to future generations. ( appendix and the hole in the retina for two examples of this )

While man can shape his environment only a benighted social scientists could think we, as living organisms. are beyond natural selection and evolution, or that we have been perfectly adapted to the present environment.

Compare morphological and biochemical evidence supporting evolution?

The morphological evidence which is shown in fossils to modern animals supports evolution because some dinosaurs, for instance, had feathers and we can obviously see that trait today in birds. The biochemical evidence, which comes in the form of DNA comparison and amino acid similarities, shows that we related closely to monkeys and pigs, which suggests that we have close ancestors to these animals.

How has your knowledge of the fossil record changed since darwin proposed his theory of natural selection?

Many more fossils have been found, some of our ancestors and we have dated the earth to be 4.5billion years old. We can take samples of ice deep in glaciers to look back into the environment at the time. We know that the further we go back in the fossil record the simpler organisms get. We can find deactivated genetic material for tails in human DNA. We have a full understanding of DNA and how it mutates and much more.

What is a hypothetical population?

Statistical population which has no real existence but is imagined to be generated by repetitions of events of a certain type.

How does the human eye invalidate evolution?

It doesn't.The human eye is sometimes used as an example of something called 'irreducible complexity'. This is a doctrine which states that because each and every part of the eye is necesary to its functioning, and that if any part is removed the eye ceases functioning as it did, that it could not have naturally evolved piece by piece and must therefore have been created by some intelligent designer.

It is a common fallacious argument put forward in support of creationism as opposed to evolution.

It is completely debunked by the simple fact that just because a part is necessary now, does not mean it was always necessary. A part is added because it is useful, and then later parts build on it, so that eventually the first part is necessary for all others; the otehr parts also build dependence over time, until the complexity is reached and appears irreducible.

The argument is similarly broken by the mousetrap analogy. Mousetraps were used as examples of irreducible complexity, because if you remove any part it no longer works as a mousetrap. However, as simply pointed out, removing certain parts makes a very effective catapult or a very simple tie clip.

How evolutionists determine if two organisms share a common ancestor?

Evolutionists determine that two organisms have a common ancestor is by looking at fossil evidence in different rock layers using the law of Superposition (Oldest layers are on the bottom, newest are on the top) and compare the skulls or other bones to each other in order of oldest to newest (or newest to oldest). Another way to determine this is to examine the amount of DNA a certain species shares with another species. An example of this would be that Humans share roughly 90% of our DNA with chimpanzees or the other Great Apes.

When was The Neutral Theory of Molecular Evolution created?

The Neutral Theory of Molecular Evolution was created in 1983.

What scientific evidence supports Darwin's theory of evolution by natural selection?

Darwin had considerable evidence at his disposal. The most famous would be the finch beaks on the Galapagos Islands. But he also noted graduated geographic differences in pigeons, as well as traits bred by pigeon fanciers. Fossils of giant sloths indicated these creatures and forms and varieties long extinct.

Probably the single biggest piece of evidence was the fact most species fit into a nested hierarchy of forms, highly indicative of shared (or common) ancestry.

Is eugenics present today?

First, we'll define eugenics. Wikipedia defines eugenics as the applied science of the bio-social movement which advocates practices to improve the genetic composition of a population, usually a human population.

We can, for the moment, exclude cattle breeding from the scope of this discussion. Of course cattle breeders are always trying to improve their stock, but this is hardly an ethical controversy.

We can also exclude parents who knowingly act to affect, through targeted breeding, the genetics of their children-to-be in such a way as to achieve a certain effect in those offspring, or the one or two subsequent generations. Eugenics is about population-wide effects, not about a few singletons wanting their children to be good at athletics.

We can also exclude governmental efforts to have teenagers practice safe sex rather than produce unwanted offspring. The effect of such a campaign has the potential to be population-wide, but the intention is not to affect the genetic composition of the population, merely to improve the quality of life for parent and child.

So the question is: are there currently movements who are actively trying to affect human breeding with the intention of achieving a specific population-wide genetic effect?

No, I don't think so.

Daing, I could have started with that last bit and left out the rest.

Which event shows the pattern of coordinated stasis?

global cooling 2.8 million years ago resulted in dry grasslands replacing wet forests in parts of Africa.

Why would evolution crease if the entire population had the same genetic makeup?

Yes. Without variation in organisms for natural selection to choose from there would be no change in allele frequency over time in the population of organisms under discussion. This is the definition of evolution, so without change over time, no evolution.

What is observed evolutionary change?

Morphological and behavioral changes that speak to, the change in allele frequency over time in that population of organisms. Go here and check observed speciation section.

talkorigins.org

Who came up with the theory that new species arise through the gradual transformation of ancestral species?

Charles Robert Darwin and Alfred Russel Wallace discovered the process of evolution called natural selection by Darwin.

Why would natural selection not occur without variations in species?

Without variation what is there to select? If you do not have variations to be selected by natural or sexual selection on their superior abilities to survive and reproduce successfully then nothing can be naturally selected against the immediate environment.