Evolution

In the past century there will be a different classification of human evolution

They both employ the same mechanism: adaptation. The difference is that in one case, subpopulations diverge to adapt to differing circumstances, and in the other, separate species adapt to similar circumstances.

Evolution and classification are related because classification systems are used to organize and categorize organisms based on their shared evolutionary history and similarities. Evolutionary relationships help scientists determine how organisms are related and classify them into groups that share common ancestry, reflecting the idea that organisms have evolved over time from common ancestors.

The term 'evolution' can refer to more than one thing.

Evolution is the word used to refer to the observed changing of allele frequencies in populations of organisms, and more generally to the observed fact that life changes over time. This is a fact, and is therefore "100% true".

Evolution is also the word used to refer to the scientific model that explains observations in biology and palaeontology in terms of what we know about the facts of evolution. Scientific theories cannot technically be said to be "100% true", but the basic hypotheses of evolutionary theory are so overwhelmingly supported by the available evidence that one might as well accept them as factual.

Evolution changes the relative frequency of alleles in a gene pool through mechanisms such as natural selection, genetic drift, gene flow, and mutation. These processes can cause certain alleles to become more or less common in the population over time, leading to changes in the genetic makeup of the population. This happens because individuals with beneficial alleles that help them survive and reproduce are more likely to pass those alleles on to the next generation, increasing their frequency in the gene pool.

Think of coevolution as an arms race. The rabbit population develops faster running ability and the fox population must have variant individuals that can keep up and these individuals are the ones who will be reproductively successful and leave these traits to the next generation of foxes and the alleles in the fox population change in frequency. Meanwhile the slower rabbits are eliminated from the population and the faster rabbits are reproductively successful, and so on.

Only the limitations of physics and the realities of variant organisms keep this arms race within the confines of the physical and biological world.

1. Fossil record: Shows gradual changes in organisms over time, with transitional fossils linking different species.
2. Comparative anatomy: Similarities in structures across species suggest common ancestry, such as homologous structures.
3. Molecular homologies: Similarities in DNA and protein sequences provide evidence of shared ancestry, seen in genetic similarities between different species.
4. Biogeography: Distribution patterns of species across different regions reflect evolutionary history, such as unique species found on isolated islands.
5. Experimental evidence: Laboratory studies and observations in nature demonstrate evolutionary processes in action, like bacterial resistance to antibiotics.

The developers of the theory of evolution by natural selection were Charles Robert Darwin and Alfred Russel Wallace.

Yes, prokaryotes are believed to have evolved before eukaryotes. Eukaryotes likely evolved through a process of endosymbiosis, where prokaryotic cells engulfed other prokaryotic cells to form a symbiotic relationship, leading to the development of cellular organelles.

Evolution explains changes in allele frequencies over time. As these changes in allele frequencies build up over time, a population can no longer be considered to be the same species it once was.

Depending on generation lengths, these changes can take days or millions of years. When these times lengths are extremely long, it is hard to determine when exactly you would say one example is species A while another is species B; however, we have observed speciation (put "observed instances of speciation" into google) and have many other evidences that speciation occurs. For example, ERVs, biogeographical distribution of species, computational genomics and proteomics, vestigial genes and structures, ring species, and more.

Yes, migration can affect evolution by introducing new genetic diversity into populations. This can lead to adaptation to new environments and potentially drive evolutionary changes within a population. Additionally, migration can facilitate gene flow between populations, influencing genetic diversity and evolution on a larger scale.

Biochemical evidence is one of the most convincing arguments in favour of evolution.

All organisms use the same energy "currency" of ATP (adenosine tri-phosphate) during respiration, despite there being no reason for it.

In the protein chains of organisms, the constituent amino acids are the same 20 amino acids which all organisms use.

The DNA code is remarkably similar in organisms. The difference between our genome and that of a chimpanzee is <1%.

Also, the DNA itself is made up of the same four bases - guanine, cytosine, adenosine and thymine (uracil in RNA) - despite this also being unnecessary.

The four forces of biological evolution are mutation, gene flow, genetic drift, and natural selection. Mutation introduces new genetic variations, gene flow allows the exchange of genes between populations, genetic drift is the random change in gene frequencies within a population, and natural selection favors individuals with traits that increase their chances of survival and reproduction.

Basically, there's only one type: the shifting in allele frequencies in populations over the generations, driven by reproductive variation, differential reproductive success, and various molecular mechanisms in genetics.

There are however numerous distinct phenomena associated with this mechanism, and different patterns to the way it affects populations, depending on circumstances. If one looks at the different 'modes' of speciation, for instance, even though they all follow from the same basic mechanisms, there are allopatric speciation, peripatric speciation, parapatric speciation, and sympatric speciation, each achieving the same thing through the same mechanisms but via slightly different paths.

The concept that many more organisms are born than can be supported by the resources of the environment they were born in. Thus the struggle for existence in which the better adapted organisms survive and reproduce in greater numbers than their conspecifics.

Let us take a random example, which is genetic drift.

A small population of beetles are on a small island. Some few are green, recessive, (gg) and most are brown, dominant (Bg and BB). So you see that the majority of the population are brown, which also happens to be the adaptively favored color. Bird populations go through a boom on this island and almost all the green beetles are eaten. The allele frequency will change through this random process of genetic drift.

One potential limitation of Darwin's theory of evolution by natural selection is the lack of a detailed mechanism explaining how new traits arise and are passed on to future generations. Additionally, the theory has been criticized for mainly focusing on population-level changes and not adequately accounting for genetic drift and other forces that can also drive evolution.

Homologous structures are features that originated in a shared ancestor, such as the bones in the limbs of vertebrates. These features may have different functions in modern organisms but have similar underlying structures due to their common ancestry.

The presence of antibiotic-resistant bacteria is a clear indication that evolution is still occurring. As antibiotics are used more frequently, bacteria can develop mutations that make them resistant to these drugs, showcasing natural selection in action.

Natural selection favors a trait by increasing its frequency in a population. Natural selection is differential reproductive success. If one variant of a trait enables an organism to have and raise more offspring successfully than other variants in a particualr environment, then it will become more common in the population.

The scientific method uses observation and experimentation to answer questions. After making observations, scientists form a hypothesis and conduct experiments to test it, gathering data to support or refute the hypothesis.

Nature has evolved over billions of years through the process of natural selection, where organisms with advantageous traits survive and reproduce. This has led to the diversity of life we see today. Environmental changes and interactions between species also play a role in shaping how nature evolves over time.

1. Lack of transitional fossils: Some argue that there is a lack of transitional fossils that show the gradual changes between different species, which is predicted by evolutionary theory.

2. Complexity of living organisms: Critics question how complex structures like the human eye could have evolved through natural selection, arguing that they are too intricate to have developed gradually.

3. Irreducible complexity: The concept of irreducible complexity posits that certain biological systems are too complex to have evolved in a step-by-step manner because they would not function without all their components present.

1. Variation: Individuals within a species exhibit differences in traits.
2. Inheritance: Some traits are passed down from parents to offspring.
3. Competition: Resources are limited, leading to a struggle for survival.
4. Survival of the fittest: Individuals with advantageous traits are more likely to survive and reproduce.
5. Natural selection: Over time, favorable traits become more common in a population through the process of natural selection.