0
Evolution
The scientific theory according to which populations change gradually through a process of natural selection.
5,264 Questions
What evidence did scientist use to support evolution theory?
First of all, evolution is a FACT not a theory. You must be referring to Charles Darwin's theory of evolution by means of natural selection. There is no denying the fact that evolution happens, scientists just didn't know exactly how it worked until Darwin suggested one plausible scientific explanation which he called natural selection. Natural selection is simply the change in allele frequencies of an organism which results that organism becoming either better or worse suited to survive in its environment. Being better suited to survive means that the organism is more likely to pass on the beneficial genetic trait to it's offspring.
Rather than asking for evidence which helps prove evolution, try looking for verifiable scientific evidence which disproves it. After all, science is not about making claims and looking for evidence to prove them, but rather generating hypothesis and looking for ways to disprove them.
What part of the cell contains DNA apart from the nucleus?
The mitochondria contain their own DNA in plants and animals; and chloroplasts contain their own DNA in plants and other photosynthetic organisms. Both of these structures divide (almost like cells) inside the cells.
*This is also evidence for the theory of endosymbiosis, in which early cells ate early prokarotic cells (bacteria) and gained new organelles.
What are the six processes of Macro evolution?
The 6 important patterns of macroevolution are:
1.Mass Extinction
2.Adaptice Radiation
3.Coverage Evolution
4.Coevolution
5.Punctual Equilibrium
6. Changes in development genes
What is a penguins vestigial structure?
A penguin's vestigial structure is its wings. Penguins have evolved to be flightless, so their wings are no longer used for flying. Instead, they have adapted to use their wings for swimming in the water.
The exchange of genetic material between chromatids is called?
Crossing over is the exchange of genetic material between chromatids. This is also known as synapsis, and it occurs during prophase one of meiosis.
the stage when an organism finds a similar organism, both of whom have qualities which may meet requirements of survival, and they thrive and procreate and thus pass along to the next generation the survival traits required for evolution.,
Why do geographical isolation is not regarded as a reproductive isolating mechanism?
Geographical isolation is not a cause of speciation in an asexually reproducing organism because the population is self-pollinating and would be less prone to the factors which results from geographical isolation.
What is important of the theory of evolution to modern biology?
All organisms alive today have been, is and will be evolving. Therefore nothing in biology makes sense except in light of evolution. For example, in medicine, the resistance of bacteria to antibiotics would not make sense except for evolution. If a drug has been killing bacteria so effectively (e.g. penicillin) for decades, why would it start to gradually become less and less effective? The answer lies in the fact that the drug creates an enormous selection pressure in favour of resistance, and this leads to an increase in the proportion of resistant bacteria in each generation. This process is an artificial and miniature version of evolution but it is evolution nonetheless. In nature, the selection pressure is usually much smaller and the process takes much longer (millions of years instead of decades).
Gerhard Lenski used the concept sociocultural evolution?
Its a concept used by Gerhard Lenski to refer to how technological innovation changes and shapes society. it is thus a process of change that results in a society gaining new information, including technology, leading to development.
What must exist in a population before natural selection can act?
Competition + Variation.
Classic example:
Giraffes not always had long necks. There were variation in the species. When food sauces grew low competition increases and those with longer necks survived (more fruit/food at the top of trees) as they were more suited to the conditions. These long necked giraffes then breed and the offspring have long necks, thus natural selection of a "fitter" species. Hense - survival of the fittest.
Which of the following ideas proposed by Lamarck was later found to be incorrect?
Lamarck thought characteristics, such as a giraffes long neck were caused by them stretching it during their lives and passing that onto their offspring - saying acquired characteristics were passed on through genetics.
What actually happens is natural selection, which means the giraffes born with long necks (by slight mutations or chance) survived better than the ones with shorter necks, as they were able to eat better, so they were able to breed and pass on the genes for long necks where the short necked giraffes died. This theory was thought of by Darwin.
How many people believe in the theory of evolution?
When the evolutionary theory was first proposed, people didn't believe it. Often, religion and evolution contradict themselves and even today, there are many people who favor creationism over evolution.
Scientific study of the Earth, including its composition, structure, physical properties, and history. Geology is commonly divided into subdisciplines concerned with the chemical makeup of the Earth, including the study of minerals and rocks the structure of the Earth and volcanic phenomena landforms and the processes that produce them and the evolution of planetary bodies and their satellites (astrogeology); and its various branches, such as mining geology and petroleum geology.
Do scientists think evolution occurs quickly or slowly?
Evolution is the stand-on ground of all biological sciences. Evolution stems its knowledge from comparative anatomy, palaeontology, archaeology, ecology and most recently and importantly, genetics and genomics. Scientists cannot 'think' much about evolution as you seem to suggest as though they have an opinion of it.
Scientists do not have an opinion on gravity or electronics or photosynthesis for example, as though they were supposed to weigh up the moral rights and wrongs of such things.
Scientists may be excited by breakthroughs of course. The unravelling of DNA structure of the emerging of natural selection as a means for species-change, or the structure of atoms revealed through encounters with gold foil, or the discovery that gene traits are expressed in pairs called alleles, or the discovery that spacetime might end, are all thrilling when stumbled upon as new insight into the world and can thus be cherished that we know a little more, but to have an opinion is not what science is all about. Thus scientists do not 'think about' science, nor of evolution. Science is about the dispassionate description of the world, however ghastly or beautiful that description may turn out to be.
The world is an unconscious babbling of atoms and their subatomic mass-energy constituents all dancing on space-time. Scientists dispassionately listen and record and try to understand the babble and try to watch the dance. They describe the babble and the dance. They do not prescribe their moral values fabricated by their own species to it. They describe the dances and leapings on the stage of space-time whether or not they think they are good are bad. Of course the unconscous, never-conscious Brownian motion leapings of atoms, whether causing embryo development or fatal cancer cannot be bad at all, or else the Universe may not even be here. But members of the public with no knowledge of science try to paste their moral values and opinions on the Universe.
Relatively educated people tend to agree there is credence in the Theory of Evolution, while less educated people often dismiss the Theory of Evolution on religious grounds. This is a pasting of one's own (maybe indoctrinated) moral values on the Universe. Some may like to prescribe these notions to the behaviour of the Universe itself. Some refuse to see credence in the Theory of Evolution or the ungodguided development of the world by the big bang or abiogenesis from a religious viewpoint. These people have no knowledge of science at all. Science is an honest description of the world which may yield alarming results.
The notion that apes and humans developed ungodguided and that there is no benevolent dominance hanging over the heads of the peoples, that all is in the vacant emptiness of the lonely Universe among randomly prancing atoms that have no knowledge of human-indoctrinated morality and can randomly prance to instigate the stirrings of embryonic life or randomly cease life carcinogenically, is a very frightening notion to some. Thus the notions of ungodguidedness or randomness in the Universe is often frowned upon and people develop opinions, and perhaps prescriptions on the truths uncovered about the Universe. Particularly, the apparent randomness, the waiting for a genetic mutation in the Theory of Evolution is frowned upon by the public. In fact Evolution is under unnecessary attack, mainly by religious objectors. Science is not a place to have opinions of the Universe, whether evolution or big bangs or DNA. Morality is a place for opinions.
A disinterested scientific picture of the Universe need not be prescribed upon. When we settle into our societies we can have the morality-opinions and the thinking-about things, but they will be based around science whose objective description need not be quibbled with. But science still seems to leave us in a vacant, random Universe full of horrible little random atoms that one cannot trust from one moment to the next. In the lonely, empty Universe, one can at least, on the curtain of space-time, be comforted by the presence of these atoms and the delicious facts delineated and expiscated by science, all swirling around one like little rainbows. You need not have opinions, or pity morality, when at least you know what the Universe is about, described by the disinterest of science.
What did darwin call the process by which evolution takes place?
The book, On The Origin Of Species, " suggested " that organisms evolve through the process of natural selection. The nonrandom survival and reproductive success of randomly varying organisms
What is geographic isolation and how does it affect speciation?
Geographic isolation refers to a situation where a species, or a population of a species, becomes separated by a physical barrier (a lake, ocean, mountains, etc.), allowing each group to diverge along separate evolutionary paths.
The effect of geographic isolation is that the two populations are subjected to different selection pressures, since the conditions in the two areas will be different. So different alleles will be selected for, and genetic differences will gradually accumulate between, the populations.
In time, enough genetic differences will occur so that the two populations will no longer interbreed. Then, by definition, they have become different species.
More Information:
Geographic isolation is the separation of two (or more) groups of organisms by a geographical feature eg. a river, mountain range, ocean, desert etc. It is the chief mechanism for allopatric speciation, still regarded by some as a theory.
Name the three different factors that increase heart rate?
Increased blood viscosity, increased cardiac output, increased pulse rate, anxiety, fear, physical exercise, Nicotine, and arteriosclerosis
What is a part of macro-evolution?
Micro-evolution is not only a part of macro-evolution, it is the same mechanism as macro-evolution. Macro-evolution includes speciation, as a result of continuing micro-evolution.
Lamarck was correct about the connection between the environment and evolution. He saw that the organism changes based on the environment and its survival. However, Lamarck is not well-known for his advances in the field. Instead, he is known for the incorrect mechanisms for evolution that he proposed, including "use and disuse" and "inheritance of acquired characteristics." (A small note, Lamarck definitely did not have a "theory," he had hypotheses).
Why was Darwin's Theory only gradually accepted?
people of Darwin's time couldn't accept his theory because they didnt believe in adaptation which has to do with evolution. Also because Darwin couldn't explain it in detail and how it works therefore his argument was weak
The study of heredity is called?
The scientific study of heredity involves the genes and this field is called genetics.
Explain the role of variation in evolution?
Variation plays a role in the process of natural selection because it keeps things mixed up. This is necessary so that one thing doesn't overtake another, ruling it out. If things are equal, one can't overrule another.
Simple.
1. Take a population of organisms. Say, for instance, fruit flies or bacteria.
2. Measure the frequencies of a set of well-defined inherited traits in this population. In other words, select some properties you know are passed on from one generation to the next, and count how many individuals in the population have this property.
3. Wait until one or more generations have passed.
4. Repeat step 2.
5. Note the difference between the frequencies measured in steps 2 and 4. This difference is called 'evolution'.
How does the field of genetics contribute to the study of evolution today?
Genetics is a very important part of biological evolution because it allowed us to study the genetics of various organisms and see how related to other species and to us they were. From this, we could work out how long it has been since two species diverged from a common ancestor based on how genetically different or similar the two species were.
