Bio Help Please- Evolution?

Question

1- Explain what the phrase "mutation proposes, selection disposes" in regard to evolution by natural selection.

2- How has the conflict between the everyday & scientific usage of the word "theory" contributed to the controversy over the theory of evolution by natural selection?

3- Why are many features of dolphins & ichthyosaurs considered to be analogous but not homologous?

4- How do "transitional forms" provide evidence for evolution? Give 1 example.
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1- ? I have NO idea, I don't really understand the phrase.

2- ? I'm not sure about this one either.

3- I want to say it's b/c they have similar traits, but that their traits aren't from a common ancestry. IDK if that is a proper/full explanation though.

4- ? I think it's b/c transitional forms show the relationship of change throughout time. I don't know how to explain that more in depth.An example would be whales.

Can someone please help explain these concepts to me.I would really appreciate it. Thanks!

Answer 1

1 - This is a nice summary phrase of natural selection. (I like it better than "survival of the fittest".) Basically, the process of random mutation "proposes" new "ideas" (a slight change to a digestive enzyme, a slight change to one of the proteins in the eye used in color vision, a slight change in a hormone relevant to sexual reproduction, whatever). And nature takes this constant production of new ideas that are "proposed" by mutation, and "disposes of" (eliminates) the BAD ideas ... the process we call "selection" ... the fact that advantageous ideas propagate faster into the population than disadvantageous ideas.

2 - The everyday usage of "theory" is fuzzy, and can range from something with a lot of evidence, to a complete guess with no foundation or evidence whatsoever. As in "I have a theory where I lost my keys." or "I have a theory about why Martina Hingis lost that tennis match yesterday." To scientists, however, a "theory" is FAR more than just a guess. It is an explanation of something that has significant evidence.

Scientists also use the word "theory" as a badge of honesty ... to emphasize that NOTHING in science is 100% sure. It is always contingent. A theory can be discarded if (a) counterevidence is found; or (b) a better theory is found that explains the *same* evidence.

Creationists exploit this fuzziness in our everyday language and use the phrase "evolution is just a theory" as a way to confuse laypeople who do not understand what the word "theory" means to a scientist ... it is NOT a wild guess ... it is something that can have a very HIGH degree of certainty.

In other words, scientists are scrupulously honest about what they do and do not know. And creationists use this honesty against them. They try to imply that if something is not 100% certain, that this is the same as being 100% uncertain ... or even 100% false.

3 - Because there are intermediate forms between icthyosaurs and dolphins that do not have these features. Therefore there is no direct developmental path between these features. For example, the flippers of a dolphin have structurally more in common with the front feet of other mammals than they do with the fins of icthyosaurs. The flippers and fins serve the similar *function* (and therefore are "analogous"), but they have a different enough structure that they are not "homologous". This tells us that other mammals are much closer w.r.t. common ancestry than were icthyosaurs.

4 - A transitional form in the fossil record provides evidence of evolution from one form to the next.

A famous example, the Archaeopteryx is a transitional form between reptiles and birds.

A long list of other examples of transitional forms:
http://en.wikipedia.org/wiki/List_of_transitional_fossils

Answer 2

1. "Mutation proposes, selection disposes" means that mutation, excuse me if this is a bit shallow, creates new alleles, helping the organism adapt to its new enviroment. It gives them a chance of survival. Natural Selection, on the other hand, singles one organism out to live in a particular enviroment and the others are "disposed of."

2. I am a bit confused with this question so I'll do my best. The theory of evolution is contradicting of the fact that there is a God. Evolution suggests that all organisms came from an ancestral organism, and that they are now adapted to a specifc place because of it. So they are saying that God did not create Adam and Eve, or the animals. That they just appeared out of thin air. Which contradicts all science. I myself do not believe in the theory of evolution.

3. They have the same features and use them in similar ways. But, they come from different anscestors. Like a fly's wings and a bird's wings. They are used for flying but they are from different anscestors.

4. Transitional forms are fossils or organisms that show the intermediate states between an ancestral form and that of its descendants. An example is the nose structure of the Beluga Whale's anscestors. Pakicetus had his nose at the tip of his skull, Aetiocetus had the nose at the middle of his skull, and Aetiocetus is also the transitional form, because it shows the change over time. Finally Beluga Whale is the final change. Its nose is at the top of its head.

I hope this helps!

Answer 3

1. This phrase suggests that genetic mutation creates larger variations to a species, while natural selection removes the created mutations which are weaker in a given environment.

2.The dictionary definition of theory is "used in describing what is supposed to happen or is possible, usually with the implication that it does not in fact happen". The word theory originated from Latin (via Greek) teoria, which actually means "contemplation, speculation". The use of 'theory' in the matter of evolution is therefore inaccurate. The concept of evolution by natural selection has no merit if it founding theories are not viewed as factual principles.

3. This means that while dolphins and ichthyology's may be considered to have the same evolutionary origin, they do not have the same ecological role.

4. Transitional Forms provide proof of evolution only if you ignore their holes (concerning evolutionary process), and irregularities ( historical evidence placing particular fossils before the stream of evolution deems they can exist). An example of a common transitional form is the hypothesized model of a ape progressing into a man.

Answer 4

for the first one:
let's say that one organism that is usually gray, mutate into two forms, one black and another white... now we have three variations, the original gray, the black and the white... that is the proposition of the mutating process. Now, let's assume that the environment in which those three variations live changes, making the rocks, amongst which the beings hide for not to be eaten, of black colour. Under such conditions, the 'black' variation proposed by the mutation has the higher chance to hide, not to be eaten, and survive to pass the genes for black color to the next generation... being 'selected'. So, the selection process disposes that the black variation survives...

Answer 5

there is not any regulation of bio-genesis. It bit the dust interior the 19th century. The miller Urey attempt confirmed that the necessary progression blocks of existence will be shaped quickly and really. Mendel dealt with inheritance no longer the nuts and bolts of genetics. Genetic limitations replace by ability of the years steadily, it really is what evolution is. and that i imagine you should analyze genetics direct from the source no longer filtered by ability of a area like AIG.