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Evolution
The scientific theory according to which populations change gradually through a process of natural selection.
5,264 Questions
Who proposed the biochemical theory of origin of life?
Alexander Ivanovich Oparin was a Soviet biochemist who, in 1924, put forward a coherent theory for the origin of life through gradually increasing sophistication of biochemical change in his book The Origin of Life.
What do scientists think about the theory of evolution?
The scientific consensus overwhelmingly supports the theory of evolution. It is considered the foundational framework for understanding the history of life on Earth and is supported by a wide range of evidence from fields such as paleontology, genetics, and comparative anatomy. Scientific understanding of evolution continues to evolve as new evidence and discoveries emerge.
How is fundamentalism at odds with the teaching of evolution?
Most religious creation myths teach that human beings (and every other form of life), were created specially, separate from all the others, for a particular divine purpose.
Evolutionary theory does not award the human race (or any other kind of life) with a special position. Each and every living thing is the end product, the summum, of a long history of surviving common ancestors, producing diverging lineages. According to evolutionary theory, we're special not because of our origins, but because of the characteristics we've evolved, which set us - but every other life form as well - apart from all the others. There is no overriding purpose to our being special, according to evolutionary theory. We're merely a product of differential reproductive success.
I believe that, in the basis, it is the issue of needing to be special in combination with the need for some overriding purpose that causes fundamentalists to reject evolutionary theory as an explanation for the diversity of life. See the answer below for an example of this.
Answer:
Fundamentalism, and religion in general, is at odds with evolutionary theory because evolutionary theory tends to be taught with the implicit message that God is not part (or need not be part) of the picture, that people do not have souls, and that there's no life after this one.
Which choice is correctly punctuated 3gal?
The correct punctuation is 3 gal. The space between the number and the abbreviation for gallon is the proper way to format this measurement.
What are all the different types of selection in biology?
There's artificial selection and natural selection.
Artifical selection is when humans breed organisms for the traits they want, while natural selection is when individuals with the best fitness survive and produce more offspring than other individuals.
Three types of natural selection are directional, stabilizing, and disruptive.
- Directional selection is when, between two traits, one trait becomes more common in a population because it benefits survival and/or reproduction more than the other trait.
For example, some bacteria have weak antibiotic resistance while others are stronger. In an environment full of antibiotic drugs, antibiotic-resistance would eventually increase in a bacteria population.
- Stabilizing selection is when, between two traits, the trait that's somewhere in between becomes the most common while the other two separate traits become less common.
For example, gall-flies produce different-sized galls. Woodpeckers eat large galls, and wasps often attack small galls, middle-sized galls, which aren't targeted by predators, become more common.
- Disruptive selection is when, between two traits, the trait in between them becomes less favorable, while the two separate traits become more favorable.
For example, lazuli buntings range between brown color and blue color. Both colors help attract mates, but the bluish-brown birds are targeted by adults, so the bluish-brown become less common as the pure brown birds and the pure blue birds become more common.
There's also sexual selection, where a trait that increases mating success becomes more common in a population over generations.
What evolutionary barrier causes an infertile offspring?
An evolutionary barrier that could cause an infertile offspring is genetic incompatibility between the parents, leading to mismatched or non-viable offspring. This can occur when different species attempt to reproduce, resulting in a hybrid that is infertile. Additionally, mutations or chromosomal abnormalities can also lead to infertility in offspring.
What is divergence in evolution?
Divergence is the growing apart of two lineages - lines of descent. Divergence may occur at the morphological, behavioural and developmental level, and will always occur at the genetic level, at least when two lineages are reproductively isolated from one another.
Can you see evolution in action today?
Yes, to a degree. In bacteria where there can be several generations in a day, we see a lot of evolution take place. In humans and elephants and other animals with longer generational turnover, we will only see slight variations because we don't live long enough. Antibiotics such as penicillin that are no longer working is an example of the evolution of bacteria.
Answer
A different influenza vaccine has to be made almost every flu season because of natural selection choosing mutations that confer greater chances for survival on influenza.
Why is the geological column considered evidence for evolution?
The geological column shows the sequence of rock layers with older rocks at the bottom and younger rocks on top. Fossils found in these layers show a progression of life forms over time, providing evidence for the evolution of species. By studying the geological column, scientists can trace the development of life on Earth and how species have changed and diversified over millions of years.
What does materialistic evolution mean?
Materialistic evolution is the idea that all living organisms have evolved through natural selection and genetic mutation, without the need for any supernatural or divine intervention. It focuses on the purely physical processes that drive evolution, such as genetic variation and environmental pressures.
What did Darwin's theories explain?
Darwin's theories explained the process of natural selection as the mechanism behind evolution. He also proposed that all species of life have descended from common ancestors. These ideas fundamentally changed the way scientists and the general public understood the diversity of life on Earth.
What types of evidence do scientists use to support evolution?
Scientists use various types of evidence to support evolution, including fossil records showing transitional forms, the distribution of species around the world, comparative anatomy and embryology, genetic similarities among organisms, and observed instances of natural selection. These different lines of evidence provide a strong basis for understanding the process of evolution.
What size populations does genetic drift occur most rapidly in?
Genetic drift is the spread of specific random variations throughout the gene pool in the absence of specific selection pressures. There's always random variation in the population, but there aren't always changes in the environment for the population to adapt to. So natural selection, in stead of moving the population towards adaptation, might select from that random variation to move 'sideways', as it were, to a state that's equally well-adapted to the environment as what came before, but different. As random variation may produce many variants that are, more or less, equally well-adapted to their environment, the direction of evolution that results is more or less random. Because variations may spread throughout small populations faster than throughout large populations, and because a large gene pool has a stabilizing effect on the spread of variations, small populations drift faster than large populations.
Evolution can occur at different rates depending on various factors such as the generation time of the organism, environmental pressures, and genetic variability. In some cases, evolution can be slow, taking thousands to millions of years for noticeable changes to occur. In other cases, evolution can happen relatively quickly, especially when organisms face changes in their environment that require rapid adaptation.
What are the scientists who study evolution called?
Scientists who study evolution are called evolutionary biologists. They research the processes of genetic change and natural selection that drive the diversity of life on Earth.
A gene pool includes all the genes, or variations of genes, within a population of organisms. This genetic diversity is crucial for adaptation and evolutionary processes. The gene pool is dynamic and can change due to factors like mutation, genetic drift, gene flow, and natural selection.
How embryology is used to study evolution?
Embryology is used in evolution because its shows a common ansetor. For example, a human and fi sh have similar embryos. Both embryos have pharyngeal slits. In a fish those develop into gills. In humans those turn into our ears.
How long does the process of natural selection and evolution take?
The process of natural selection and evolution can vary in terms of the time it takes, ranging from hundreds to millions of years depending on the species and environmental factors. Evolution is a gradual process that occurs over generations as populations adapt to their changing surroundings through natural selection.
Does natural selection affect individuals populations or both?
Natural selection primarily affects individuals within a population. Over time, as certain traits offer a survival advantage, those individuals will be more likely to survive and reproduce, passing on these advantageous traits to their offspring. This process can lead to changes in the population as a whole.
The presence of a dominant allele is not always required to explain common traits in a population. Polygenic inheritance, where multiple genes contribute to a trait, can lead to common traits without a dominant allele. Additionally, environmental factors can also play a significant role in shaping common traits among a population.
What idea advocated survival of the fittest?
" Survival of the fittest " is an inaccurate phrase coined by one Herbert Spencer, though Darwin did use this phrase in later edition of The Origin. The theory of evolution by natural selection showed how the " fit " survive and, more importantly, achieve reproductive success.
Tell your teacher to stop using this phrase!
What is a genetic drift and when does it occur?
Genetic drift is the spread of specific random variations throughout the gene pool in the absence of specific selection pressures. There's always random variation in the population, but there aren't always changes in the environment for the population to adapt to. So natural selection, in stead of moving the population towards adaptation, might select from that random variation to move 'sideways', as it were, to a state that's equally well-adapted to the environment as what came before, but different. As random variation may produce many variants that are, more or less, equally well-adapted to their environment, the direction of evolution that results is more or less random. Because variations may spread throughout small populations faster than throughout large populations, and because a large gene pool has a stabilizing effect on the spread of variations, small populations drift faster than large populations.
I study evolution because it is the concept that underlies all of biology. Biology would still be natural history without the fact of evolution and the theory of evolution by natural selection is the overarching theory that underpins all of biology while explaining much about the fact of evolution.
" Nothing in biology makes sense, except in the light of evolution. " Dobzansky.
PTA should be punctuated with periods as an abbreviation for Parent-Teacher Association.
How does natural selection sometimes create a change in a populations?
Natural selection constantly causes change in populations by making them change over time, and occasionally split to form new species.
For example, if a population stays together, but their environment starts to change, then natural selection will pick the fittest organisms of that population to live and pass their traits on to their offspring, causing a gradual change in the genetic makeup of the entire population
Another example of natural selection on a population is speciation, or the formation of a new species. If the population is separated geographically, behaviorally, or temporally, the 2 sub groups can adapt to different climates and gradually become so different that they can't mate anymore, so they become 2 separate species.
add Natural selection may be seen in action today. The emergence of herbicide resistant plants and insecticide resistant populations of insects are well documented.
It must be said, that if the new threat (herbicide/insecticide) vanished, the population may well revert to the previous form. But if the new challenge remains significant, then it becomes dominant.
