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Evolution
The scientific theory according to which populations change gradually through a process of natural selection.
5,264 Questions
How are these two biomes alike and what adaptation do plants living in each biome share?
Both deserts and tundras are characterized by harsh climates with extreme temperatures and limited precipitation. Plants in these biomes share adaptations such as shallow root systems to maximize water absorption and the ability to store water. Additionally, many desert plants have thick, waxy coatings to reduce water loss, while tundra plants often grow low to the ground to withstand cold winds and conserve heat. These adaptations enable them to survive in their respective environments.
What parameters are necessary for natural selection?
Natural selection requires variation, inheritance, and differential survival and reproduction. Variation refers to differences in traits among individuals in a population; inheritance means these traits must be heritable, passed from parents to offspring. Differential survival and reproduction occur when certain traits provide a reproductive advantage, leading to those traits becoming more common in subsequent generations. Together, these parameters drive the evolution of species over time.
their anatomical structures and genetic sequences. By studying these similarities and differences, scientists can infer how closely related different species are and how they have evolved over time. This evidence helps to trace the evolutionary history of different animal groups and understand how they are all connected through a common ancestor.
What is the evolutionary advantage of having large hands and feet?
Large hands and feet can provide better grip and stability for climbing, running, and hunting. They also allow for more efficient movement through various terrains, enhancing an individual's ability to find food, escape predators, and navigate their environment effectively. Additionally, they can serve as a visual signal of strength and fitness to potential mates, aiding in reproductive success.
Advantages and disadvantages of electrical engineering?
Electrical engineering offers numerous advantages, including the ability to innovate in diverse fields such as telecommunications, renewable energy, and automation, contributing significantly to technological advancement and improved quality of life. However, it also presents challenges, such as the need for continuous learning to keep up with rapid technological changes, and potential exposure to health risks from high-voltage systems. Additionally, electrical engineers may face job pressure due to tight deadlines and the complexity of projects. Balancing these factors is essential for success in the field.
Later evidence from genetics and molecular biology showed that acquired traits are not passed down through generations as proposed by Lamarck, as they do not alter the genetic material. On the other hand, Darwin's theory of natural selection was supported by the discovery of the mechanism of inheritance through genes and DNA, providing a more robust explanation for evolutionary change over time.
Is macroevolution both a fact and theory?
The terms macroevolution and microevolution were first coined in 1927 by the Russian entomologist Philipchenko. Macroevolution is the term now used to refer to any evolutionary change at or above the level of species, such as the splitting of a species into two or the change of a species over time into another species. Microevolution refers to any evolutionary change below the level of species, and can also apply to changes that are not genetic.
Creationists often assert that macroevolution is not proven, even if microevolution is, apparently meaning that whenever evolution is observed it is microevolution, never macroevolution. These claims are considered a misuse of authentic scientific terms. Macro Evolution is a theory; it is also a fact.
For more information, please visit: http://christianity.answers.com/theology/the-story-of-creation
What is small differences between parents and offspring accumulate over time?
Genetically over many generations mutations and differences can occur and that is called Evolution. If we are talking within a single generation and general behavior charicterstics, I'm not sure that has a name. This is just the sum of a person's experiences are what makes them. the whole nature vs nurture debate.
What percent of Europeans accepted Evolution over Creation and how does it compare with the US?
In a survey published in 2006 the question asked was "Human beings, as we know them, developed from earlier species of animals". Approximately 40% of the US stated that this was true with 21% unsure and 39% rejecting. In Europe the figures vary by country from Cyprus at about 45% saying this was true to Iceland at about 80%. 27 European countries have about 50% or greater support for Evolution. Belgium, Norway, United Kingdom, France, Sweden, Denmark and Iceland all come in at about 75% or above. These figures are slightly tentative as all I have is the graph that summarises the results rather than the paper which was published in Science.
The best way to respond to this is to explain that there is the fact of evolution and the theory of evolution. Evolution is defined as genetic change within a population. This is an easily observable fact both in nature and the laboratory. The theory of evolution is an explanation for the diversity of life on earth based on the observable facts that evolution does indeed occur. It is exactly the same situation with gravity. Gravity is a fact, an easily observed physical phenomenon. But there is also a Theory of Gravitation, an explanation for the phenomenon itself and how it works. That there is a theory for both evolution and gravity does not mean the facts of evolution and gravity are any less true.
It is important to note that sickle-cell anemia comes in two forms. The homozygous sickle-cell anemia and the heterozygous sickle-cell trait. The difference between the two is that sickle-cell anemia has a high rate death rate at a young age (20~), and the sickle-cell trait is nearly asymptomatic.
In regions such as North America, sickle-cell anemia would be selected against and would eventually leave the gene pool. The sickle-cell trait on the other hand, has little effect on the fitness of the organism, and as such will remain in the gene pool.
In malaria endemic regions such as sub-Sahara Africa, sickle-cell anemia provides very high levels of immunity to malaria and the sickle-cell trait provides a slightly lesser level of immunity. Both forms of sickle-cell will increase the organisms fitness and as such, it will remain in the gene pool. Further on, the sickle-cell trait has greater fitness than sickle-cell anemia, hence, the sickle-cell trait will be selected as the fittest allele.
If s is the sickle-cell allele and S is a normal allele;
The relative fitness in malaria endemic regions;
Ss > ss > SS
Sickle-cell trait > Sickle-cell anemia > Normal
The relative fitness in non-malaria endemic regions;
SS > Ss > ss
Normal > Sickle-cell trait > Sickle-cell anemia
Quite true, but you can refine the definition ecologically speaking and say this is also a form of competitive exclusion.
Skull can provide an amazing amount of evidence of the anatomical changes that have occurred in hominids over time. Observations of the size of the skull can give us clues on how much the brain has evolved.
Will someone explain to me exactly what evolution is and why atheists believe it?
Evolution is a theory put forth by a man called Charles Darwin. He postulated that animals evolve over time, and that when animals gain favorable mutations, it increases their chances of survival and therefore mating. When they mate they pass on their mutations to their young and spread the change throughout the species. Atheists, who don't believe in a god(s), find that this is the most likely way that animals came to be on earth.
See related links.
Was there an ice age during the Triassic Period?
Since the climate at the time did not contain much rainfall and the weather was very dry and hot weather, it can be concluded that there was most likely not an ice age at the time.
What is the book The Greatest Hoax on Earth about?
The full title of this book ''The Greatest Hoax on Earth:Refuting Dawkins on Evolution'' is another rebuttal by creation scientist Dr. Jonathan Sarfati. It attempts to answer Richard Dawkins recent work ''The Greatest Show on Earth.''
Dawkins outlined in his book what he regards as the best evolutionary evidences -something he realised he had not done in a number of his previous works. Dr. Sarfati refutes each alleged evidence point by point.
Among a number of things which Dawkins states is his often-repeated assertion that the eye is badly designed, due to the backwards-facing retina. Sarfati says this is questionable, since Dawkins' design would put the opaque choroid layer of blood vessels at the front of the eye -which would be like having a continuous black eye his other suggestion would make it impossible for regeneration after exposure to bright light and so it would take months for us to be able to see again each time we looked outside on a bright day. Sarfati quotes opthalmologist Dr. Goerge Marshall who stated "The idea that the eye is wired backward comes from a lack of knowledge of eye function and anatomy."
Sarfati also states that Dawkins continues to use straw-man arguments -pointing out things which creationists do not believe, in order to make his case. Sarfati suggests that Dawkins use of straw-men is inexcusable -that Dawkins should find out and address and refute what creationists actually say.
Answer
In reference to the bad design Dawkins alleges for the human eye (and Sarfati's refutation):
Sarfati states (in response to Dawkins comments about the alleged 'backward wiriing') "Once more, Dawkins shows no understanding of the need to regenerate the photocells, which necessitates this 'backward wiring'. (Greatest Hoax, p 273) Earlier Sarfati explains why Dawkins' allegedly superior design is nothing of the sort as it "would require either - the choroid in front of the retina-but the choroid is opaque....so this would be as useless as an eye with a hemorrhage! - Photoreceptors not in contact with the RPE or choroid at all- but without a rich blood supply to regenerate, then it would probably take months before we could see properly after we were photographed with a flashbulb or we glanced at some bright object." (Greatest Hoax p 271-272) Thus Sarfati shows that Dawkins' alleged better design is not better at all.
Sarfati's overall thrust is to demonstrate the ignorance of Dawkins in relation to the overall structure of the human eye, which does what it does very well, just as the octopus eye serves the octopus very well, in its particular environment. He also points out that the octopus does not see colour as humans can, nor is their vision particularly sharp. Sarfati also refers to a statement by ophthalmologist Dr George Marshall who said "The idea that the eye is wired backward comes from a lack of knowledge of eye function and anaotomy." (Greatest Hoax p 271). He also refers to the work of ophthalmologist Peter Gurney who also has written a thorough refutation of the idea that the human eye is badly designed (op. cit. p 274).
At the end of this section Sarfati also makes the point that alleging bad design does not in any way demonstrate how evolution created the eye in the first place.
Sarfati acknowledges in his epilogue that this subject is a big one. A listing of the chapter headings certainly reveals this to be so:
1. Bait-and-switch.
2. Species and Kinds.
3. Natural Selection.
4. Evolution before our very eyes?
5. Embryos and self-assembly.
6. Common ancestry or common design?
7. Where are the transitional fossils?
8. The links are still missing.
9. Ape-men?
10. Geographical distribution.
11. Is the earth ancient?
12. Young world evidence.
13. Origin of Life.
14. Lost structures:evolution or devolution?
15. 'Bad design':evidence for evolution?
16. "Nature red in tooth and claw"
17. Evolution, science,history and religion.
The above list shows that he has met Dawkins on a wide field of alleged evolutionary evidence. Acknowledging the limitations of such a work and the greatness of the topic he points to the 7000+ articles available on one creationist website alone (Creation Ministries International). He highlights the repeated misrepresentation of the creationist position by Dawkins and suggests it is better to read what creationists actually say and believe than the version presented by Dawkins (examples scattered throughout the book).
What happens to a populations alleles as they change one time?
Evolution is the change in the frequency of alleles of a population of organisms over time.
False. Relationships that that were not apparent to classifiers before the theory of evolution by natural selection was developed were brought into sharp relief by the theory. Mans place in nature, such as his close relationship with the great apes, could now be seen clearly.
Do hedgehogs and echidnas show an example of divergent evolution?
Hedgehogs and echidnas show convergent evolution.
Despite being far apart, they ended up looking very similar.
Like sharks and dolphins.
What are the stages of evolution from ape to human?
ok i am not an evolutionist but i do know the ape to human phase.
It starts at a piece of dirt to a bug then a butterfly to a snake to a mouse to a rat to a brand new baby monkey to an adult monkey to a ape to a gorilla to human then from human all the way back down to nohing.
Evolution is the change in allele frequency over time in a population of organisms.
Viruses do have DNA and RNA, so the can change allele frequency over time and have a form of gene pool, though they are not organisms in the general sense of " living organisms. "
Loosely, one can say that a virus evolves.
