0
Evolution
The scientific theory according to which populations change gradually through a process of natural selection.
5,264 Questions
Natural selection is the only mechanism of evolution that will lead to?
the adaptation of a population to its environment through the gradual accumulation of beneficial traits.
Compare convergent divergent parallel evolution?
Convergent evolution is when two unrelated species develop similar traits due to adapting to similar environments. Divergent evolution is when two species with a common ancestor develop different traits due to adapting to different environments. Parallel evolution is when two related species independently develop similar traits due to adapting to similar environments, but they do share a recent common ancestor.
In what situation will speciation occur?
Speciation occurs when populations of a species become reproductively isolated from each other, typically due to geographic barriers, genetic mutations, or other factors that prevent interbreeding. This isolation leads to the accumulation of genetic differences over time, eventually resulting in the formation of new species.
Biochemical analysts use similarities in what as evidence for evolutionary relationships?
Biochemical analysts use similarities in molecules like DNA, proteins, and enzymes as evidence for evolutionary relationships. The more similarities there are between the molecules of different organisms, the closer their evolutionary relationship is believed to be.
Do shared derived characters show common ancestry?
Yes, shared derived characters indicate a common ancestry among taxa. These characters are traits that are unique to a particular group and are inherited from a common ancestor. The presence of shared derived characters in multiple species suggests that they share a common evolutionary history.
What animals have evolved through natural selection?
Many different species have evolved through natural selection, including finches, peppered moths, giraffes, and bacteria. Natural selection is a key mechanism in evolution that favors traits that improve an organism's chances of survival and reproduction in its environment.
What is evolution in genetic terms?
In terms of a population, evolution is just the change of allele frequencies over time. Natural selection can cause certain advantageous alleles to increase in frequency, and detrimental alleles to decrease in frequency.
Darwin and Lamarck had different ideas about why all giraffes now have long necks why?
Lamarck would have said that the ancestors of
modern-day giraffes had short necks but stretched
their necks as they tried to reach leaves in trees; so,
their descendants were born with longer necks.
Darwin would have said that in a population of
ancestral giraffes, some had slightly longer necks
than others; the long-necked giraffes were better
able to feed on tree leaves and as a result produced
more offspring. Over time, the proportion of longnecked
giraffes in the population increased.
Vertebrate colonization of terrestrial habitats increased dramatically with the evolution of?
lungs and limbs, allowing vertebrates to breathe air and move efficiently on land. This facilitated the transition from aquatic to terrestrial environments and enabled vertebrates to exploit new ecological niches.
How do organisms change over time according to evolutionary theory?
Organisms change over time through the process of natural selection, genetic mutations, and genetic recombination. Over generations, advantageous traits are favored, leading to the accumulation of genetic changes in a population, resulting in biological diversity and adaptation to the environment. This process is at the core of evolutionary theory, explaining how organisms have evolved and diversified over millions of years.
How did life begin according to the evolutionary theory?
The Theory of Evolution does not seek to how life began, although there are several very credible hypotheses for the beginning of life on Earth.
The traditional view is that, billions of years ago while the Earth was still hot and there was extreme volcanic and lightning activity, organic chemicals began to form out of the simpler inorganic chmicals that abounded. These organic chemicals became more and more complex, until RNA molecules (the precursors to DNA) formed. Once RNA, and then DNA molecules existed, life was ready to begin.
Another hypothesis is based on the ability of some crystals to replicate themselves, even replicating the defects that occasionally formed. In a 'dirty' environment, carbon atoms could attach themselves to those crystals and become replicated along with the crystal itself. This self-replication is not yet life, but could conceivably lead to the development of life.
This is known as the "Arctic gene hypothesis," where individuals from Arctic regions may carry more body fat as an evolutionary adaptation to survive harsh cold climates and food scarcity. Having more body fat provides insulation and energy reserves which are crucial for survival in cold environments where food may be scarce. In contrast, individuals from tropical regions may have evolved to have less body fat due to the abundance of food and a need for efficient heat dissipation.
Three major trends of evolution in vertebrate brain?
1. The size of the brain relative to the whole body increases in certain evolutionary lines.
2. Increased specialization of function.
3. The increasing sophistication and complexity of the forebrain.
According to Urban Dictionary, Orgism refers to the creation of a parallel universe.
What is the importance of environmental preservation?
{| |- |
Environmental preservation is needed to assure economic and social benefit for a longer period of time. Land, water and air are polluted and our mineral resources are depleted. We need to conserve our environment. There are dozens of little things we can all do to save energy and water.
* Wash full loads of laundry and dishes, etc.
* Take shorter showers
* Turn off the faucet while brushing your teeth
* Fix leaky faucets and sprinklers at home
* Install smart sprinkler controllers
* Direct grey water to the garden
* Plan water wise gardens
Also check out this link to know more tips on water and energy conservation http://www.bewaterwise.com/tips01.html .
|}
Why not all traits are adaptations?
Some traits are accidental. Genetics have an element of random variation whether by the recombination of genetics that comes with sexual reproduction, or by mutation, and while some changes can be selected for or selected against by the evolutionary pressure described as "survival of the fittest" there are also changes that make little if any difference to the survival of the organism or of the species, and so, they are not subject to evolutionary pressure. Therefore they are not adaptations, they are just accidents.
Are organisms able to consciously direct the course of their own evolution?
No. Evolution is a consequence of selective pressure(s) from the environment acting on organisms. Virtually all living beings are not conscious of this process.
The only species that *could* consciously direct its own evolution is Homo sapiens (humans), but currently it doesn't.
Artificial selection can and has consciously directed evolution, but it always was a species acting over other different species, not on their own evolution.
What is Darwins theory of evolution?
Darwin's theory of evolution is basically 'Survival of the Fittest" or "Natural selection." Genetic mutations occur in every species. Sometimes these are beneficial. For example a calf born more muscular than the rest will be more likely to mate and consequently pass on his genes to his
all organisms have been living for millions of years. change over time.
Darwin's theory of evolution by natural selection. Short and memorable explanation.
Natural selection is the nonrandom survival and reproductive success of randomly varying individual organisms.
How do scientists tests ideas about chemical evolution?
Scientists test ideas about chemical evolution by using computer models.
In the evolution of vertebrates what is the significance of being a tetrapod?
This is probably looking at the adaptation from water to land.
* Land has different types of food
* Migration out of water to land means less competition for food and less predators
* Air is far less dense than water and easier to extract O2
Why is it best for scientists to use the scientific name of an organism instead of a common name?
Using the scientific name ensures clarity and precision, as common names can vary across regions and languages. Scientific names follow a standardized naming system (binomial nomenclature) which helps scientists accurately identify and classify organisms worldwide.
The role of an organism in its community?
The term niche is used to define the role an organism plays within a community.
Why do scientists hypothesize that earth is about 4.5 billion years old?
Scientists have concluded from abundant evidence and the analysis of that evidence, that he earth is about 4.5 billion years old. This is more than merely a hypothesis, since they have the evidence for their conclusions.
Scientists realised nearly two hundred years ago that the earth must be at least a few million years old. Early in the nineteenth century, Charles Lyell examined the great volcano of Etna on Sicily and studied the historical records of frequent eruptions. He noticed that each time it erupted, a new layer of lava would be added, causing the mountain to grow at a measurable rate. By knowing the height of the volcano, its approximate rate of growth and the frequency of eruptions, Lyall determined that the volcano must be several hundred thousand years old. At the edge of the volcano, under the first lava flows, he found fossil shells that were virtually identical to the shells of molluscs still found in the Mediterranean Sea. From this, he deduced that the fossils were geologically recent, that a hundred thousand years was geologically short and that the age of the earth must be immense.
In 1862, Lord Kelvin announced that he had calculated the time it would take the world to cool down from its molten state. He calculated that this was between 20 and 400 million years, but later refined his calculations to within the range 20 to 100 million years. With the subsequent discovery of radioactivity, it was soon realised that the uranium present in the earth could have prolonged its cooling for as long as necessary to harmonise with other methods.
Samuel Haughton, an Irish geologist, calculated that sediments were deposited on the ocean floor at the rate of "one foot in 8,616 years". He then calculated a minimum duration of around 2000 million years. Unwilling to accept such a long period, he scaled it back, by a factor of 10, to just 200 million years.
In the early years of the twentieth century, Rutherford established the age of a rock as 500 million years, by measuring the amounts of radium and helium present. Strutt soon realised that some of the helium would have escaped as the rocks were crushed for analysis, leading to false short estimates of the ages of the rocks - they were really even older than the initial estimates.
In the late 1930s and early 1940s, using the new techniques and the world's most advanced mass spectromoter, Alfred Nier dated some rocks at up to 2570 million years old.
The oldest things so far found on earth are zircon crystals found in Western Australia, that are more than 4 billion years old.
Some Young-earth Creationists have incorrectly claimed that Noah's Flood could have altered the rates of decay for radioactive elements found in rocks on the earth, so that the earth is really only a few thousand years old. However, any effect from a Flood on the earth would not have affected rocks on the moon or in outer space. Zircon rock collected from the surface of the moon has now been identified as more than 4.5 billion years old. Material from meteorites has also been dated to approximately 4.5 billion years old. These figures support the calculations for the age of the earth.
What causes evaporation to happen faster?
Higher temperatures, lower humidity levels, an increase in surface area exposed to air, and greater air movement all contribute to faster evaporation. Heat provides the energy needed for water molecules to break free from the liquid and enter the air as vapor, while lower humidity levels create a larger gradient for water molecules to move from the liquid to the air. Increasing the surface area exposed to air or having more air movement helps speed up the process by reducing the concentration of water molecules in the immediate vicinity of the liquid surface.
