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Questions tagged [evolution]

Changes in the heritable attributes of populations of organisms over time. The mechanisms of evolution are mutation, migration, drift, and selection.

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How old is the action of sneezing?

Is there an estimate for when the ability of sneezing evolved? A little bit of research, and some critical review of my memories tell me that: Many, if not maybe all mammals sneeze. Some reptiles ...
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How does DNA code for the actual *shape* of individual body parts/areas (NOT segments or Hox genes)?

Just to save the trouble - I am not asking for general information on how DNA codes for proteins and definitely not how Hox genes work. I have a very good understanding of the evolutionary process and ...
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Will our biological bodies be changed after we’ve occupied and settled Mars? [closed]

I had this question in mind for very long time, and I could not find a clear answer on the Internet, so I was hoping that you might know the answer. If we will bring life to planet Mars and a few ...
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Why do simulations of dichromatic color vision portray medium wavelengths as yellow rather than green?

Please take the time to read & answer this at your own convenient pace. Is this even the right way to put this? Do you think this post better belongs in the Physics or Philosophy forums? This ...
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What is the meaning of 'state of nature' in On the Origin of species by Charles Darwin?

I have started reading "On the origin of species" by Charles Darwin. The beginning paragraph is: When we look to the individuals of the same variety or sub-variety of our older cultivated plants ...
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34 views

Why does the HLA show a high degree of polymorphism?

I know how the HLA undergoes high degree of polymorphism (random genetic rearrangements), but I have not understood why it undergoes rearrangements. What is the advantage offered when HLA shows a high ...
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1answer
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Are bears related to dogs in a similar way to how cats are related to 'panthers'?

I've tried searching on Wikipedia but I couldn't find what family dogs belonged to. Ursidae is 'bears' and Canis is 'dogs' ; Panthera is big cats like:- tigers and jaguars is what I know.
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Why do so many parasites infect definitive and intermediate hosts rather than just one host?

Many parasites infect multiple host species, with one host species being the definitive host (where the parasite reproduces), and the other host species being the intermediate host (where the parasite ...
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How to determine the number of parameters in a phylogenetic model?

I want to calculate the AIC for a phylogeny that I inferred via maximum likelihood. To calculate the AIC I need to know the number of parameters in the model. But how do I determine this?
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What is an accessible book about plant evolution for a non-biologist? [closed]

I have an acquaintance interested in learning about the evolution history of plants. This person has a wide knowledge on botanics, from personal reading and taking care of plants, but E is neither a ...
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1answer
43 views

Why is melanin black? [duplicate]

I understand that the function of melanin is to protect individuals from sunlight, and that people living in sun exposed areas are darker due to increased production of melanin. But why is the melanin ...
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176 views

Is there any known reason why 6 leg mammals are only found in mutations? [duplicate]

Taking a look in internet you can find photos of mutated mammals with 6 legs. Some cows with legs in unnatural positions were shown in website versions of widely known newspapers (you can easily guess ...
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Mutation rate and Evolutionary rate?

What is the difference between then?I have read some jobs that describes analysis about mutations rates and another ones with evolutionary rates.I want to know the diferrence between then.
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Is evolution of gametangia in land plants and charophyceae convergent?

Is the presence of gametangia in both land plants and charophyceae a result of convergent evolution or are they of the same origin (and have been lost in other types of algea)?
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Do biologists believe in the existence of an intelligent creator who designed the architecture of life ? [closed]

I am referring to the biologists who does not support the theory of evolution or Darwinism .
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speciation in a single population

Most examples of speciation describe a population splitting (via various mechanisms) into two or more populations that eventually become separate species from one another. However, what if the ...
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Do ring species exist?

In trying to understand evolution better, I have been looking at examples of speciation, and have thus come across the topic of ring species. I have tried to find concrete examples of how these work, ...
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Can I simulate a previous and next sequence of my fasta files?

I have fasta sequences of a virus protein that had suffered a mutation in 2008 and this mutant had increase it fitness when compared to wild strain (according to literature).I want to simulate if my ...
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How would inserting a nonfunctional protein impact fitness of an organism?

Producing proteins costs energy, and producing longer proteins costs more energy than shorter proteins. Producing proteins which have no function, would therefore presumably negatively impact the ...
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You need DNA to make RNA, and RNA to make DNA, so they had to come into existence at the same time?

A statement I recently read: 'Evolution is debunked and gives no basis for morality. Natural Selection throws away info, it does not add. You need DNA to make RNA, and RNA to make DNA, so they had to ...
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28 views

Can I make an population genetic analysis from incomplete protein?

I have an dataset of fasta sequences. This proteins are not complete (My sequences have 700 nucleotides,while complete sequences have 1725 nucleotides)I would like to know if i can make an population ...
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Are mutations a source of genetic variation?

Here is a question from the book SAT II Success Biology E/M (where the SAT is the exam taken by the American high school students): Which of the following statements is true about mutations? (A) ...
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What function will survive evolution?

I wrote the following phrase in my scientific text: X is ubiquitous in life of Y. On some occasions X might be detrimental, resulting, for example, in so so phenomena. But is it plausible that a ...
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1answer
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Cichlid fish in Africa

Are the cichlid fish in Africa an example of divergent or convergent evolution? On the one hand they have evolved similar features to each other indicating convergent evolution, but on the other, they ...
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Has evolution made a mistake with prehistoric animals?

Let me start this by saying I have very limited knowledge in biology and evolution. However, when visiting museums and watching documentary movies, I always get impression dinosaurs (and other ...
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2answers
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Cross-species infections

I’ve heard that HIV developed from SIV, etc. I’ve also heard that most species (including most monkeys) can’t get a common cold like humans. So then what causes infections to be able to travel ...
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How can two biological sequences be anything but homologous?

If we consider homology between two nucleotide sequences as a yes/no answer to whether they have shared a common ancestral sequence, then given that all life share common ancestry and sequences are ...
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Genes related to senses and their variation across animals

Animals often have very different numbers of active genes related to any sense. For instance, most fish or even aquatic mammals have very few olfactory receptor genes, whereas this is higher in ...
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Mating patterns and genetic superiority

In peacocks and peahens, the peahens prefer mating with peacocks having a large and bright tail. But how is having a large tail an indicator of genetic "fitness" (in survival terms) ? If having a ...
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Is it appropriate to say “selection of” or “selection for” an allele that evolves by genetic hitchhiking?

In terms of Sober's selection of/selection for distinction, is it appropriate to say that there was selection of or selection for an allele that evolved by hitchhiking? I am inclined to say selection ...
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Coacervater were more like Viruses or Cells?

The answer considers them as first formed living cells as they were precursor of life. But they had no lipid bilayer nor any cellular organization, shouldnt they be more like Viruses ,or like Prions ...
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3answers
60 views

Why are there few tetrapod dinosaur carnivores?

Today, most big carnivores are quadrupeds. Bears, Tigers, wolves. During the Jurassic and the Cretaceous, carnivores were mostly bipedal, dinosaurs mostly from the Therapod family. Why was ...
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1answer
37 views

How can biologists rule out multiple early organisms that went through conjugation?

The current idea is that all life evolved from a single cell. Analysis indicates the probability of two different origins being very unlikely, given shared DNA. However, why couldn't numerous ...
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If virus is an inanimate(non-living) structure, why it poses tendency/intelligence to spread itself to others?

A virus has no aim, no agency but just a chemical propagation(DNAs, RNAs). Still, it accounts for millions of deaths and horrible nature. Rabies, for example, is a very deadly disease with a fatality ...
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What is the closest relative to odd-toed ungulate?

I have seen about 3 variation of phylogenetic tree about odd-toed ungulate and I don't know which one is really updated or outdated or which one have more backed up theory First is odd-toed ungulate ...
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1answer
50 views

Genotype-Phenotype evolution distinction

I understand the difference between the genotype of an organism and the phenotype of an organism, (genotype being the genetic code, phenotype being the physical expression), however I am unsure about ...
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Among primates, is it true that homosexual behavior is extremely unnatural and uncommon?

I was recently reading a book published by some anonymous biologist known as Lynn Saxon, in which she appears to want to refute Christopher Ryan's thesis in Sex at Dawn that prior to the invent of ...
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Are there lifeforms that have more than 2 sexes?

Are there any lifeforms on earth that have more than male and female biological sexes? If so, are all three mates required for reproduction or is there something else going on? If not, why not? ...
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166 views

What is the difference between phyletic and phenotypic gradualism?

As I understand it, Phenotypic gradualism describes the development of new traits as a series of incremental steps. How is Phyletic gradualism different?
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Is there mismatch in injures or death numbers for carnivores that hunt during day time and night time?

Is there significant mismatch in injures or death numbers for hunters (when hunter was killed or injured by its prey), between day time and night time hunts (carnivores that hunt during the day time ...
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90 views

What makes red meat less healthy than seafood, after millennia of evolving to eat meat? [closed]

We are told that red meat is carcinogen; fish and white meat are not. What make us not "compatible" to red meat after thousands of years of evolution and meat eating, and yet seafood is opposite ?
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are there any species that we can identify as being 'mid-way'though an evolutionary change?

I have just learned that dolphins evolved from a dog/cat like land mammal (Mesonix) that became ever-more water venturing. I understand and can visualise how the arms legs and tail slowly evolved into ...
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Are cloned spieces significantly more vulnereble to deseases than sexually reproducing species?

I would like to be able to compare the risk for species to go extinct implied by their reproduction mechanism in the very short term. Imagine we choose some species A that can reproduce both sexually ...
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1answer
48 views

Does homology of a trait necessarily imply that the most recent common ancestor had the trait?

If two different species have a trait that is homologous, does this mean that the most recent common ancestor necessarily had the same trait?
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1answer
62 views

Does a reproductively successful male have the same genetics as a reproductively successful female?

Evolutionarily, using humans as an example, it would make sense that a successful female would produce successful male offspring. If a successful female produced male offspring that weren't successful,...
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1answer
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Why do dozens of preys run away from a clearly outnumbered predator? (e.g. zebras and lion)

We are all familiar with scenes where dozens (if not hundreds) of zebras, sheep, or other preys are chased by one lion, one wolf or other predator. Examples are all over youtube, but here is one of ...
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3answers
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Is existence of different alleles for a gene a result of mutation?

I would like to understand evolution. Here are a few questions Why are there different alleles for a gene? Is the different alleles of a gene are mutated versions of a gene? Why selection pressure ...
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Why, evolutionarily, does the genus Latrodectus have such potent venom?

As far as I know, the venom of most species of spider in the family Theridiidae is not dangerous to humans. However, the genus Latrodectus is well known for having venom medically significant to ...
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Reversal form of endosymbiotic theory?

Cell's organelles give us evidence that they might have been independent organisms on their own. Are there any single-cell microorganisms known to have gone so to say this way back as well, i.e. ...
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146 views

Does evolution produce organisms perfectly adapted to their environment? [closed]

I have this biology assignment with this chosen topic. I have no idea where to start researching. I have studied the mechanisms and theories of evolution. I just don't know which relates to the topic. ...