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Evolution
The scientific theory according to which populations change gradually through a process of natural selection.
5,264 Questions
Why doesn't evolution occur through the inheritance of acquired characteristics?
Because acquired characteristics are not programmed in the DNA; only characterisitics which are genetically programmed are passed on and inherited.
Inorganic evolution is the theory of the creation of the universe, not of the species of animals found on earth (ie organic evolution). It does seem to be a point of contention among a few as how this led to complex compounds. There is no connection as no scientific evidence has shown it, yet.
No, evolution is not directional as the definition is; the change in allele frequency over time in a population of organisms. Google barnacle to see that evolution has no particular direction, but the adaption of the organism to the immediate environment.
Who is Ardi and why is she important?
Ardi is important because she is the oldest human skeleton in the whole world. She lived 4.4 million years ago.
Ardi shows upright walking with a somewhat prehensilefoot, but no "knuckle walking" like the Great Apes.
What was Charles Darwin's Theory of Evolution?
Charles Darwin's theory of natural selection applies to organisms who adapt to their environment better than others and survive to pass on their traits to offspring. Due to variation in their genes, may be caused by mutation but rarely so, organisms are able to adapt to their environment. If they don't adapt well they die. If they adapt to their environment it means that they have fought for their survival and are now able to pass on their variations to their offspring and make them stronger. Often as a result a new species is formed due to the accumulated differences.
There are three types of natural selection: Directional, disruptive, and stabilizing selection. In directional selection only one extreme genotype is favored to pass on. Meaning the environment chooses one genotype to pass on. An extreme genotype for example would be either SS or ss for sickle cell, either the genotype for sickle cell is passed on or the non-sickle cell genotype is passed on. In disruptive selection, a disruption separates similar organisms causing the favoring of two extreme genotypes. For example both SS and ss are favored to pass on. In stabilizing selection only the middle genotype is favored meaning Ss which is carrier of sickle cell.
Natural selection is when the environment determines which alleles enable organisms to survive.
The theory of natural selection states that traits in a species become more or less prevalent depending on environmental pressures that select either for or against such traits.
Individuals that have traits that better suit their environment are more likely to survive.
Darwin broke down the process into 4 steps:
1. individuals that make up a population vary in their traits
2. some of these trait differences are heritable
3. in each generation, many more offspring are produced than can survive. Only some individuals survive. Of these, some will produce more offspring than others
4. Individuals with certain heritable traits are more likely to survive and reproduce.
Natural Selection occurs when individuals with certain traits produce more offspring than do individuals with certain traits produce more offspring that do individuals without those traits.
when organism adapt to the environment they will be likely to survive and produce healthy offspring.
Humans have countered natural selection by medically correcting phenotypes?
Humans have countered natural selection through hybrid breeding. Even crossing a male donkey with a female horse produces a mule. Crossing certain corn strains with other corn strains to produce more grain per ear.
Why does evolution require diversity within a species?
If everything is exactly the same, there is a lower chance of evolution occurring; diversity is not necessary, but it works quicker. This is because where random mutation is the only thing to introduce wider genetic diversity, it will take a longer time than simply mixing the gene pool up.
What are the four levels in the evolution of TQM?
1- Inspection: conformity evaluation by observation and judgment accompanied as appropriate by measurement, testing or gauging.
2- Quality control: part of quality management focused on fulfilling requirements.
3- Quality assurance: part of quality management focused on providing confidence that quality requirements will be fulfilled.
4- Total quality management: the application of quality management principles to all aspects of the organisation, including customers and suppliers, and their integration with the key business processes.
Miller and urey's experiments attempted to demostrate?
Miller and Urey's experiments attempted to demonstrate the chemical origins of life. They first conducted the experiment in the year 1953.
For humans, a motor skill that is common among all cultures.
Which behaviors would some evolutionary psychologists offer as proof of their theory?
all the answers are correct
Which of Lamarck's ideas turned out to be true Which turned out to be false?
Right: adaptions to environment
wrong: acquired traits are passed on
DNA and RNA provide evidence of evolution because?
They are shared and used by every living thing on earth and many whole sequences of DNA show close correlation, or exact sequence. One can actually follow the mutation trail from a common ancestor to the descendents that branch off from this ancestor.
Only evolutionary theory explains this as the creationist explanation, many separate creations and linear progressions of organisms, can not explain the shared and variant sequence trail.
Yes, use the Hardy-Weinburg equilibrium equation.
From an evolutionary stand point fitness is measured in?
Reproductive success is the coin evolution pays in.
He might not of if Malthus had not been around but he depended on the works of Lyell.
Complex forms of life evolved over long periods of time from simpler forms?
According to the theories of Charles Darwin complex forms of life evolved over long periods of time from simpler forms.
Evolution is always happening. Species are constantly changing to adapt to their surroundings. If evolution wasn't always happening, many different species would have died.
Is there molecular evidence for evolution?
Take the cytochrome C electron shuttle in the electron transport chain and see how it is highly conserved in form and function among a wide variety of eukaryotes. That is molecular evidence for the relatedness of widely disparate organisms.
The basic mechanisms of evolutionary change cannot be observed in nature?
No. Evolution can be observed in both nature and laboratory settings, the main problem is that it's difficult to view in humans because humans live a long time and also cover the entire planet. Since humans live so long and are everywhere, most of the mechanisms behind evolution take a very long time to have any effect.
Looking at species that don't live so long or that can possibly migrate/move, evolution is easily observed. Take ring species, a population starts at one end of a "ring" shaped land mass, the population then splits, one half moves around the ring one way while the other half moves around the ring another way. This population which was the same species with the same traits becomes very different by the time they reach the other side of the ring.
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.
