Evolution

Vestigial organs are remnants of structures that were once functional in an organism's evolutionary past but are no longer needed. The presence of vestigial organs provides evidence for evolution by natural selection, as they demonstrate how organisms have changed over time in response to their environment. These structures support the idea that species have evolved from common ancestors and help to illustrate the concept of descent with modification.

There is no " what do I understand by the term evolution. " Evolution is the change in allele frequency over time in a population of organisms. This is a observed and observable fact.

It is no longer Darwin's theory of evolution by natural selection, but has had over 150 years of modification and improvement to become the modern synthesis.

A short definition of natural selection.

" The non-random survival of randomly replicating organisms. "

Strictly speaking, reproductive fitness is meant. The organism that has the most and best quality progeny adapted to the immediate environment will leave more representations of it's alleles in the population gene pool and the allel frequency will change over time fulfilling the definition of evolution.

One big Hardy-Weinberg assumption is that there is no mutation taking place in the population of interest. Mutation and selection lead to evolution, which the Hardy-Weinberg assumption also does not allow in a population. So, if there is the variation brought about by mutation then there is a chance of natural selection happening and this violates Hardy-Weinberg assumptions.

Natural selection over long periods of time leads to the gradual evolution of species, as individuals with advantageous traits are more likely to survive and reproduce, passing on those beneficial traits to future generations. This can result in the emergence of new species or changes within existing species to better adapt to their environment.

1. DNA- test the similarity in DNA

2. Fossil Records

3. Embryology- study of embryos during development shows the traits ancestors of humans once had such as gills and post anal tails.

4. vestigal structures- structures no longer in use can show what ancestors of the organism needed

Darwin's theory of evolution is based on the concept of natural selection, where individuals that are better adapted to their environment are more likely to survive and reproduce. Over time, this process leads to the accumulation of beneficial traits within a population, resulting in the gradual change of species. Additionally, Darwin's theory highlights the importance of variation within a population, genetic inheritance, and the gradual divergence of species over long periods of time.

The legal battle over teaching evolution, such as the Scopes Monkey Trial in 1925, was a showdown between modern science and religious beliefs. These conflicts often revolved around the separation of church and state, with proponents of evolution arguing for the teaching of scientific principles in schools without religious interference. The outcomes of these legal battles have shaped the modern education system and continue to influence discussions around science literacy and religious freedom.

Bottleneck
That is a condition of the Hardy-Weinberg law and the population is said to be in Hardy-Weinberg equilibrium , but it is an idealization that never happens in nature.

Darwin used the phrase "descent with modification" in his book "On the Origin of Species" instead of the word "evolution." He used this phrase to describe the process by which species change over time through natural selection.

Mendel's conclusion on the segregation and independent assortment of traits laid the groundwork for Darwin's theory of natural selection by providing a mechanism for how variation is passed down from one generation to the next. This understanding of how traits are inherited allowed Darwin to propose that natural selection acts on this variation to drive the evolution of populations.

The theory of evolution by natural selection. Evolution is a fact explained by the theory. Short explanation.

Natural selection is the nonrandom survival and reproductive success of randomly varying individuals.

Evidence from paleontology, molecular cell biology, genetics, biochemistry, geology, evolutionary biology, evolutionary development (evo devo ), embryology and a host of other disciplines, such as anthropology.

These show that alleles frequencies change over tim in populations of organisms.

These show that all organisms on earth are related in morphology and function.

Developmentally organisms are related. Vestigial evidences of relatedness.

Biogeographically evidences

A change in the frequency of a particular gene in one direction in a population is called genetic drift. Genetic drift refers to the random fluctuation of allele frequencies in a population over time, leading to a change in the genetic composition of the population.

Selective breeding, also known as artificial selection, is a process carried out by humans to develop desirable traits in plants and animals. In nature, natural selection is the driving force for change over time, where organisms with advantageous traits have a better chance of survival and reproduction, leading to those traits becoming more common in a population. While similar in principle, natural selection occurs without human intervention, unlike selective breeding.

Finding out how exactly traits are passed on to offspring - with variation - filled in a gap in the understanding of evolution that Darwin pioneered. Darwin did not know or understand how it could come to be that traits propagated through the generations with only minor variations, without blending. He could only assume that there was some mechanism that facilitated this propagation. His fear was that further research into genetics would show that sexual reproduction blends traits. Had that been the case, then evolutionary theory would have been falsified. In stead, what we learned about genetics - starting with Mendel, and culminating in the findings of Watson and Crick - confirmed what we'd learned about evolution in great detail.

Genetic drift is the random change in allele frequencies in a population. It is caused by chance events and has more pronounced effects in small populations where genetic diversity is lower. Over time, genetic drift can lead to the loss of certain alleles or fixation of others in a population.

The theory of punctuated equilibrium suggests that evolution occurs rapidly in short bursts followed by long periods of stability. This contrasts with gradualism, which proposes that evolution happens slowly and steadily over time. Punctuated equilibrium is supported by the fossil record, where evidence of rapid changes in species can be observed.

Genetic drift is change in allele frequencies due to random chance events.

Two types are the Founder effect and the Bottleneck effect.

The founder effect is when a subset of a population goes to a new are where there are no other of that same species.

The bottleneck effect is when a large population is reduced to a small population.

Genetic drift decreases variation in a population and has a greater effect on a smaller population than a larger one.

That is just another name for Charles Darwin's theory of natural selection--i.e., evolution. The term is often misunderstood by the public and misconstrued by people with ideological-based biases wishing to reflect evolution in a negative light. Here, "survival of the fittest" doesn't refer to the biggest and strongest, but to the individuals who survive longer and pass on more offspring. For example, elephants are by far the most powerful land animals in the world, but there is no way that they could survive under water, where it is populated by fish. Though much, much weaker than elephants, fish are better suited to the underwater environment because they have special adaptations like gills, fins, and air bladders. This means they are more fit than the elephant in this context because they will thrive in this environment and will produce more offspring.

During the Archean Eon life started and was dominated by one-celled prokaryotic life forms. Eukaryotic one-celled organisms became dominant in the Proterozoic Eon. Multicellular organisms ruled the planet during the eon known as the Phanerozoic.

Natural selection changes the genetic makeup of a population by favoring some genotypes over others. It does so through the differential reproduction of those genotypes. Put simply, if I possess a variant of a trait (and the genotype underlying it) which allows me to leave behind more adult offspring than those with different variants of that trait, then my variant will become more common in the population than the others. The result is a change in the frequency of the gene variants: mine increases in frequency at the expense of the others. This change in the frequency of gene variants (known as alleles) over time in a population is the basic definition of evolution itself.

1. Genetic mutations that quickly change the phenotype of a species, resulting in rapid evolution.
2. Environmental changes that create selective pressures, leading to sudden shifts in species adaptations.
3. Isolation of small populations that undergo rapid speciation in response to new ecological niches.

Adaptations enhance an organism's survival and reproductive success within its environment by increasing its ability to cope with challenges like finding food, avoiding predators, and reproducing. They allow organisms to better match their environment, improving their fitness by increasing their chances of passing on their genes to the next generation.

Generally, yes. To have a wide variation in a population of organisms means that your population is better able to meat environmental challenges and survive through an onslaught of parasites, such as bacteria and viruses.