Evolution

In science, a theory is a well-substantiated explanation based on evidence and testing. The ideas about evolution are called theories because they have been extensively researched, tested, and supported by a wide range of scientific evidence from various fields such as genetics, paleontology, and comparative anatomy. Evolutionary theory is considered one of the most robust and well-supported theories in biology.

Charles Darwin was not the first to recognise the role of evolution, but he did recognise that evolution came about by variability and natural selection. Darwin believed that when a natural variation gave a survival advantage, that individual was more likely to survive and pass on the genes responsible for that variation. He saw that varieties can be developed in a sufficiently short period to be studied, and said that evolution of species is just an extension of the observed evolution of varieties. Darwin said that [in nature] a well marked variety can justly be called an incipient species, although the variety, for any number of reasons, may never progress to becoming a distinct species. He published his most important work, The Origin of Species, in 1859 and The Descent of Man in 1871.

There are three basic reasons:

1. Natural Selection-- thr environment may have favored the allele in previous generations, but now disfavors it.

2. Genetic Drift-- in every finite population, the frequency of an allele will fluctuate due to chance. For example, the vast majority of sperm fail to fertlize any egg, so allels can be lost this way due to chance. Individuals carrying a copy or copies of an allele may die young due to random accidents, or may never find a mate. These basic chance events cause the frequencies of alleles to fluctuate, and the degree of frequency change depends upon the population size. The greater the population size, the smaller the change in frequency.

3. A combination of both.

fossils show the bone structure of ancient animals. you can see remarkable similarities between them and animals today. For example, the bone structure of many dinosaurs were very similar to that of birds today. For humans we found a bunch of steps on our evolution that is very good evidence of it.

Darwin was inspired by Thomas Malthus's idea that populations grow faster than the resources available to support them. Darwin applied this concept to the natural world, suggesting that individuals within a species compete for limited resources, leading to a struggle for survival. This struggle, along with natural variation and heritability of traits, forms the basis for natural selection, where individuals with advantageous traits are more likely to survive and reproduce, passing those traits on to their offspring.

Lamarck believed that changes acquired during an animal's life could be inherited by their offspring. We now know that inheritance does not work in this way.

For example, if you are a body builder, and develop big muscles, your children will not inherit large muscles.

Inherirtance works through genes, which are inherited through the egg and sperm from the parents.

Some people believe in it while others do not. Belief itself is irrelevant. The theory could be true or false regardless of how many people believe or disbelieve.

I personally accept it as accurate due to the evidence that the fossil record and DNA gives us but many Christians (and those of other religious beliefs) believe that to say that Evolution is real is to deny that God created everything. There are those who believe that God created evolution. Evolution is a theory but in science terms a theory is a widely accepted (by scientists) explanation supported by data.

The evidence evolution occurs runs rampant through the genetic code of modern species and through the fossil record. Compare the earliest amphibians to sarcopterygian lungfish. Considered legged cetaceans. Examine the human chromosome that is a fused pair of "monkey: chromosomes. Contemplate the GULO gene. Why should we share a defective gene for the synthesis of ascorbic acid with old world monkeys?

These are all strong indicators evolution has occurred, though the theory of evolution is the explanation that ties these facts into a coherent picture.

Inheritance of acquired characteristics. According to Lamarck, organisms could pass on traits they acquired during their lifetime to their offspring, leading to evolutionary change. This mechanism has been largely discredited in modern evolutionary biology, with natural selection being the predominant mechanism for driving evolution.

As populations of organisms evolve, different properties of their cell membranes are selected for or against.

Selection pressure caused by the invasive species entering the ecosystem. They would be possibly competing for the same resources with different traits that might favor one species traits over the others on average. The native species is a population of variants, so some among the native population could compete with the invasive species on a more equal footing. These would be naturally selected by being reproductively sucessful, ultimately, and thus change the allele frequency in the native populations gene pool; the definition of evolution.

Homologous structures are similar structures that related species inherit from a common ancestor. These structures may have different functions in different species but share a similar underlying anatomy, suggesting shared evolutionary origins. Examples include the wing of a bird and the flipper of a whale, both being modified versions of the forelimb structure shared by their common ancestor.

Helicobacter Pylori, the main cause of gastric cancer, has evolved differently in separate peoples, slightly modulating disease risk. This is usually used as part of a persons risk assessment for cancer, IE; African H. Pylori ancestry was relatively benign in humans of African ancestry but was was found to cause more harm in individuals with substantial Amerindian ancestry, etc.

Work is the physical or mental effort exerted to achieve a purpose or result. It changes over time due to advancements in technology, shifts in the economy, changes in work arrangements, and evolving skills required in the workforce. The nature of work continues to evolve as society progresses.

I think you mean genetic drift.

Genetic drift is not strong enough in itself to cause speciation generally. Genetic drift is merely a sampling error in allele frequency change due to random events.

Allow me to show you the evolution of classical music.

Convergent evolution is a process where different species independently evolve similar characteristics due to similar environmental pressures. This can result in species from different lineages developing analogous traits to adapt to a shared ecological niche. An example is how both dolphins and sharks have evolved streamlined bodies for efficient movement through water, despite not being closely related.

Evolution, the change in allele frequency over time in a population of organisms, is a fact. Show evidence that this does not happen. I think you would find that very difficult to show since change in allele frequency is so easy to observe.

Now, to show that the theory of evolution by natural selection is wrong, you must come up with a better explanation of evolution. So far no one has done that.

Darwin's three major contributions to evolutionary thought are;

1. There is genetic variation in all species

2. The variability is inherited - passed from parents to offspring

3. There are more offspring born than that survive to reproductive age

Darwin's theory of evolution by natural selection is widely accepted in the scientific community and forms the foundation of modern biology. It is supported by abundant evidence from various fields such as genetics, paleontology, and comparative anatomy. While some aspects of the theory have been refined and expanded upon over time, its core principles remain a fundamental part of our understanding of how life has diversified on Earth.

No arguments; evidence.

1. The biochemical and genetic relatedness of all organisms on earth.

2. Biogeography. The distribution of organisms best explained by evolution.

3. Homology. The bones in your arm match almost bone for bone the bones in your dogs forelimb. ( save for structural modifications )

4. The age of the earth and the processes that took place over deep time. Well supported from many disiplines.

When two different groups separate enough they can start evolving differently.

This might happen with two groups that separate when a subgroup moves to a different continent for instance.

The subgroup, over time, may begin to evolve in response to conditions in the new place, and the group left behind will not benefit from those changes. However, it might develop more adaptations to its own environment.

In humans, independent assortment occurs during meiosis, when the 23 pairs of chromosomes divide into 46 individual chromosomes, and 1 chromosome from each of the 23 pairs goes on to form a gamete (haploid cell) which can then be fertilised to produce offspring. The assortment is "independent" because each of the 23 chromosomes that go on to form a gamete can be from either chromosome within a "pair" - ie the 23 pairs of chromosomes are not linked together in any way when it comes to meiosis. This means that a large number of combinations of genetic material is possible - introducing a random result in the gamete.

Plant hybridization demonstrated that new varieties could be created by intentionally crossing different plants, challenging the idea that species were fixed and unchangeable. This process allowed scientists to select for desirable traits and improve crop yields, leading to a shift in the understanding of biological diversity and the potential for genetic modification in plants.

Scientific evidence suggests that life began on Earth approximately 3.5 billion years ago. The Earth formed 4.5 billion Years ago.

The Earth was a dead planet for about 1 billion years.

Some evidence would suggest that the first forms of life began more like 3.8 billion years ago, in which case the Earth was dead only 700 million years.

The study of the processes which resulted in the beginning of life is called Abiogenesis.

If it worked the same on other planets on other Sun in other galaxies, life may have begin 10 billion years ago in other galaxies.

See related links.

Note also that there are dozens of explanations for the beginning on life on Earth, including many based on religion.