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What is the definition of "Natural Selection"?

Official definition Is there an official definition of natural selection that is adopted by biologists nowadays? and what is that definition exactly? I don't think there is such a concept as an "...
Remi.b's user avatar
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11 votes
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Was Darwin aware of the difficulties behind the concept of species?

The whole point of Darwin's theory was that transition from one species to another is extremely slow and gradual. There are plenty of quotes in "Origin of Species" stating this, and also affirming ...
IMil's user avatar
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9 votes
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Can domestic breeding be considered evolution?

Yes, selective breeding results in evolution. Definitions of evolution I don't understand why you say that for 3 of the definitions you found, selective breeding would not be considered as evolution....
Remi.b's user avatar
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8 votes
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Are 'homeothermic' and 'endothermic' synonymous?

[D]o homeothermic and poikilothermic have the same meaning as endothermic and ectothermic respectively[?] No. Once you are referring to the source of the heat, while the other time you are referring ...
Remi.b's user avatar
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8 votes

What is the difference between a cytokine, a hormone and a protein hormone?

Parts of the answer are in the text that you provide yourself. But I shall try to add where i can. What do each of these three terms [hormone, cytokine and protein hormone] mean and how are they ...
Jonas's user avatar
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8 votes

What is the definition of "Natural Selection"?

I've adapted your definitions to another process that I think will be less controversial to you. Eating is the intake of food by taking into the mouth, chewing, and swallowing. Eating, the process ...
Bryan Krause's user avatar
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7 votes

What is the exact definition of a "gene"?

I found a dedicated paper about the definition of what is a gene. Their short definition is: “a gene is a discrete genomic region whose transcription is regulated by one or more promoters and distal ...
KaPy3141's user avatar
  • 1,597
6 votes

Evolution as a directed graph exploration?

But in order to find shortest path, which is known well from algorithmic theory, you have to be as broad as possible. You try to explore as many vertices, as possible, which means you're creating ...
Oosaka's user avatar
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6 votes
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About the definition of ketogenic amino acid

The fundamental 'problem' with acetyl-CoA is that it cannot be converted to glucose via the tricarboxylic acid (TCA) cycle: a two-carbon compound (acetyl-CoA) enters the TCA cycle, but two carbons are ...
user338907's user avatar
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5 votes
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Introgression vs admixture

The difference is referring to the directionality of gene flow. We talk about genetic introgression when there is some gene flow from one population (say, population A) to the other (say, population ...
Remi.b's user avatar
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5 votes
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Is studying chemical and physical properties of chemical substances that make up organisms really a task of molecular biology?

If you look at the Google ngram for the term ‘Molecular Biology’ you will see that it first appears just before 1960, and it is relevant that the Journal of Molecular Biology was founded in 1959. It ...
David's user avatar
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5 votes
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What is the exact definition of a "gene"?

Folks were identifying genes for 75 years before we understood the role of DNA in heredity. Originally genes were defined as the unit of heredity from back when Mendel posited that the mechanism of ...
Charles E. Grant's user avatar
4 votes
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Problem with an analogy (Cell Membrane)

Osmosis is the diffusion of water. Pinocytosis is the endocytosis of liquid/water.
user30605's user avatar
4 votes

Do apes and humans share 99% of DNA or 99% of genes? What is the difference?

Most of the answers here focus on the difference between the concepts of 'DNA' and 'genes' very well. However, the sequence identity between humans and chimpanzees is not covered as rigorously and ...
AlexDeLarge's user avatar
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4 votes

Can domestic breeding be considered evolution?

The answer is "yes". Evolution is defined as a change in heritable characteristics of a population over generations, and to me, there is no reason not to define domestic animals as populations. The ...
Mikko's user avatar
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4 votes
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What do the column labels in this table mean?

F(1,22) is the result of an F-test with degrees of freedom 1 and 22, in this context most likely this is an F-test in the context of ANOVA; for the meaning of those degrees of freedom I would suggest ...
Bryan Krause's user avatar
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4 votes

Evolution as a directed graph exploration?

Your theory is based on many false assumptions. Evolution becomes nothing but a finding a shortest path in that unbelievably huge directed graph. What makes you think that evolution followed the ...
IMil's user avatar
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3 votes
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Usage of "lineage" over "species"

Lineages have many levels, it is like using the word groups in some ways, they are stacked inside each other like the worlds biggest branching Russian nesting doll. All vertebrates is a lineage, all ...
John's user avatar
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3 votes
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Can an exotic species be also endemic?

I think this partially depends on the timeframe. Endemism is usually divided into paleoendemism and neoendemism (see e.g. Kier er al in PNAS for use of both terms). Here, neoendemism is referring to ...
fileunderwater's user avatar
3 votes

What is the philosophical definition of life?

There is no difference along the lines of philosophy vs. science. However, there are broader and narrower definitions in biology. The broadest I know of is "a self-replicating, chemical system (...
John's user avatar
  • 14.7k
3 votes

What is the philosophical definition of life?

They ask different questions. Philosophy may ask what is life, is there a purpose behind it, etc. Biology asks how does it work, chemistry what are the chemical reactions that drive it, physics maybe ...
Filipe Rocha's user avatar
3 votes

What is a gene transcript, how is it different from an allele?

No. A gene is a unit of the genome stored in the form of DNA. It can be transcribed into mRNA (the transcript) to be used as a template in protein synthesis. A gene can come in many different ...
Bob's user avatar
  • 556
3 votes

What is the difference between abiogenesis and spontaneous generation?

What truly differentiates abiogenesis from spontaneous generation? There are three differences. Frequency Abiogenesis occurs very infrequently. Perhaps only once in all of earth's 4.5 billion year ...
JayCkat's user avatar
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3 votes

What is a section in botany based upon?

Taxonomic rankings above the species level are arbitrary—that is, they are created just to be a useful handle, much the way one might call the plants in one’s study “my study plants” and the plants in ...
resplaine's user avatar
  • 109
3 votes

Actual definition of cardiac output

Cardiac output is the amount of blood pumped only by the left ventricle, per minute.
Anonymous's user avatar
  • 307
3 votes

What does "crude" mean in this context?

In this context crude means naturally occurring or unrefined. Purified trypsin alone, for example, is usually ineffective for tissue dissociation since it shows little selectivity for extracellular ...
Johnny's user avatar
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3 votes
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Can the word phalanx also be used to describe the finger bone plus the soft parts around the bone?

It's a great question, and in my humble opinion, the answer is: Phalanx (plural: phalanges), (also Cambridge and MedicineNet) is the term for one of the bones (only) in the fingers or toes and not ...
Jan's user avatar
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3 votes
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What is the meaning of deep winter mixing?

The winter mixing of stratified layers in lakes and seas due to temperature changes can vary in depth, so scientists sometimes say "deeper winter mixing" and "deep winter mixing". ...
bandybabboon's user avatar
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3 votes
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Meaning of some unit of measurement of kinase activity

It is not a specific unit of kinase activity, rather a general approach taken for following reactions where there is no change of colour. The abbreviation cpm stands for counts per minute and is a ...
Bjarte Lund's user avatar

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