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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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Why are Mules/Donkeys aggressive when faced with predators but horses are not?

I came upon an interesting quote after going down the rabbit hole on a variety of subjects. While deep in the data, I came upon this quote oat and farm animal owners likes to have mules with their ...
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The pectoral fins of a whale and a shark. Are they analogous organs?

Analogous organs: Different origin, same functions, Homologous organs: Same origin, different functions but same main structure// right? So, what is the case for the pectoral fins of a shark and a ...
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231 views

Is a fully functional hermaphrodite possible in humans? [closed]

Is it possible for someone to achieve asexual reproduction if they had complete fully functional reproductive system? What problems might they encounter during conception and fetal development? If ...
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1answer
23 views

Increase rate of change in coding regions?

If a sequence is under selection will it acquire more changes over time because of faster fixation than if changes were neutral? Is this true or am I missing something?
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1answer
68 views

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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What exactly happens to animals that fail mating rituals?

Quite a few animals (usually males) participate in various mating rituals to showcase their fertility as mates. While presumably, the successful ones get a chance to mate with females, it occurred to ...
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1answer
77 views

In what does Genetic clustering and Cline sharpness differ?

They are both ways to measure divergence in species but I'm not understanding in what exactly the differ if both use hybrid zones and gene frequencies in the study.
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1answer
85 views

Black oyster of sweet water

I have seen recently a documentary starting with introducing of the spectacular black oyster of sweet waters which imitate exactly like a prey fish in order to convey its eggs to predator fish's gills,...
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Why do my pets have eyebrow patterns?

I own roborovski hamsters and a duprasi. They both have little white “eyebrows” above their eyes. This is very cute, but I’m not sure what function it serves. I know humans have eyebrows to try and ...
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34 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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3answers
16k views

How scientists can be confident that human embryo tail is really a tail?

From Wikipedia: Human embryos have a tail that measures about one-sixth of the size of the embryo itself. As the embryo develops into a fetus, the tail is absorbed by the growing body. How are we ...
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Short videos on evolutionary biology

What I am looking for I'm considering to eventually start my teaching sessions with short emotional, awe-inspiring or exciting videos that are somehow related to evolutionary biology incl. diversity ...
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4answers
87 views

What's the benefit of the average human body temperature?

Why would the body choose a resting temperature of 36.1c to 37.2c? It seems a very inefficient mechanism of survival considering the typical ambient temperatures on Earth. If there is a benefit to ...
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2answers
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Is the suicide of a moribund individual to be considered group selection?

When a moribund individual commits suicide (e.g., Refardt, Bergmiller & Kummerli, 2013; http://rspb.royalsocietypublishing.org/content/royprsb/280/1759/20123035.full.pdf), is this to be considered ...
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Why don't all organisms reproduce asexually?

According to a comment at Why are not all species hermaphrodites?, asexually reproducing species go extinct more easily. However, I don't think sexual reproduction is a true evolutionary stable ...
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1answer
222 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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Why is AUG the initiation codon?

Is there any reason why AUG is the initiation codon? Can’t translation start with different codons?
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1answer
54 views

How are the first mammary glands thought to have functioned?

I happened upon a book (not about biology) containing this text: A life-changing birth occurred on the planet about 190 million years ago [...] the first tiny shrew like creature brought forth an ...
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1answer
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Can anyone help me with these Biology evolutionary properties homework questions? [closed]

my teacher assigned these worksheet questions, they are ungraded, but he said something might come up on the test really similar to this so I really want to get all of them right. I am pretty ...
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Are genes for producing heterozygotic twins sweeping?

The tendency for a woman to ovulate two or more eggs at once, which may results in a heterozygotic multiple births is the way I understand it at least to some part genetic. At least since the ...
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2answers
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How does better sperm result in more viable offspring?

Quoting wikipedia: Greater choice and variety of mates increases a female's chance to produce more viable offspring. This led me to the question: "How sperm parameters are connected with entity ...
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3answers
273 views

Have humans finished evolving?

I thought that massive changes among organisms are over long periods of time. This is caused by, to my knowledge: Evolutionary pressure Natural/artificial selection Mutations Genetic drift Will ...
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What is the difference between different schools of taxonomy?

I have been quite interested about biology lately. I would like to know what are some of the main differences between schools of taxonomy. Thank you for the answer!
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2answers
182 views

Why do many people seem to prefer unhealthy compared to healthy foods?

I don't have any concrete statistics on this but many of us seem to love the taste of food that is unhealthy for us. Over the centuries, wouldn't it have been a non negligible advantage to those who ...
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How many times have Ecdysozoans made the transition to land? [duplicate]

In my evolutionary course we were taught that land plants are a monophyletic group, the transistion to land happened only once. The same goes for the tetrapods within the vertabrates. However this ...
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Is there a vertical measure of appearance of a genotype over generations?

Is there some kind of a vertical measure of appearance of a genotype $g$ throughout ancestry, i.e. a measure of how many ancestors of $g$ had genotype $g$. Like for example in saying that on average ...
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Are microbial antigens selected against?

Antigens provoke a response from the host immune system. Could selective pressures result in microbes losing their antigens? Has this been observed? Or are antigens typically so important that they ...
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6answers
4k views

Why are there species instead of a continuum of various animals?

As I understand it, various animal traits have to evolve gradually, but what happens to the species that are "neither here nor there"? To put it differently, if a species evolved from another, it did ...
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1answer
129 views

Discrepancy in time for genetic differences between human and chimpanzee to accumulate

Genetic differences between human and chimpanzee include ~50,000 amino acid changes, ~30,000,000 point mutations in non-coding sequences, and millions of insertions, deletions, inversions, genomic ...
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4answers
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What is the definition of “Natural Selection”?

Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. Natural selection, a process that results in the adaptation of an organism to its ...
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2answers
638 views

Why do the ancestors of birds still exist? [closed]

If I am not mistaken, scientists believe that birds are evolved from reptiles. Why do the ancestors of birds (that is, reptiles) still exist?
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3answers
11k views

What is meant by `individuals do not evolve, populations do`?

My university professor stated that "individuals do not evolve, populations do". But aren't populations made up of individuals? That's like saying when a compound changes in stability, none of the ...
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5answers
910 views

How does Darwinian Evolution work?

Let me explain... A friend and I read some articles, part of a Biology book, and watched a video on evolution. We then tried to explain what Evolution is to each other. My friend said that Natural ...
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3answers
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Did cats evolve from monkeys ? or vice versa?

Did cats evolve from monkeys? or vice versa? How similar are the genes of cats and monkeys? What is the proof that they are related or that they are not related? Most monkeys climb in trees and ...
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24 views

Is Wikipedia a good source of taxonomy? [duplicate]

I have been quite interested in biology lately,and I would like to know whether it is a good choice to look up taxonomic information there.
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2answers
109 views

Are Males the main evolutionary tool for production of genetic variation necessary for evolution?

What I'm saying here is just a personal reflection, that might turn to be gravely erroneous, actually I'm asking that because I didn't see it presented elsewhere. Evolution is propelled by two ...
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0answers
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What are haplotype blocks and what is the effect of hybridization on these?

In this PDF, there is a quick definition of haplotype blocks. A haplotype block is a set of closely linked alleles/markers on a chromosome that, over evolutionary time, tend to be inherited ...
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8answers
4k views

Is there a biological mechanism for evolution encoded into our DNA?

Throughout high school, I remember learning about Darwin's theory of evolution as if it were near-fact. But something always seemed wrong about the ideas presented. Survival of the fittest Random ...
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1answer
74 views

Can threat to survival increase mutation rates in germline cells?

Can stress that is related to a threat of survival of a population of animals or plants in some environment, like due to hunger, thirst, fear from predators, etc..; results in an increase in average ...
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1answer
483 views

Is evolution a predictive theory? [closed]

My feeling is that almost any observation can be explained by current evolutionary theory. Is there any example of someone developing a rigorous framework or mathematical model of how evolution works?
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4answers
2k views

If we sequenced the genome of every species, would all phylogenies agree?

The Tree of Life is still up for debate. Most of this debate seems to be due to a lack of genomic information, but that deficiency is decreasing rapidly with advances in technology and sequencing ...
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2answers
563 views

How is “selection” best defined?

There is natural selection but there is also sexual selection which some regard as a category of natural selection. There is also artificial selection (by humans). The question is, what is a most ...
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773 views

Are we “more evolved” than present-day bacteria?

The common ancestor of humans and modern bacteria was most likely a prehistoric bacterium. Does this mean that humans are "more evolved" than today's bacteria?
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Is this model of understanding of what's natural selection and what's not, correct? [closed]

Here in this account I just want to make sure, that I've grasped the concept of natural selection as is usually spoken by evolutionary biologists, truly the wording here are non standard and in some ...
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1answer
252 views

How can the number of genes increase through evolution?

I am aware of the basics of evolutionary theory, however I don't understand how mutations can add genes over time. Am I correct in thinking that creatures within the same species who mutate to have ...
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2answers
2k views

Why is the strength of genetic drift inversely proportional to the population size?

I saw a concept on the Internet that says "the strength of genetic drift is inversely proportional to the population size". I don't know why they are inversely proportional? Can somebody explain? ...
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2answers
902 views

Why haven't land animals evolved beyond urination?

It occurred to me (while urinating) that this would seem to be selected against because water is a scarce resource. Why are we constantly losing water we don't need to through urination? What is ...
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2answers
2k views

Why do humans grow taller than their ancestors?

I'm taking the Introduction to Genetics And Evolution course and in the first lecture it was said that: Evolution in a biological sense is simply a change through time. And very importantly, that ...
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8answers
14k views

Why do some bad traits evolve, and good ones don't?

If a trait would be advantageous to an organism then why hasn't it evolved yet? Conversely, if a trait is not advantageous or mildly disadvantageous, why does it exist? In other words why does ...
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5answers
4k views

Why do most animals never seem to evolve over millenia?

People often say, including those with extensive knowledge in biology, that a certain species of animal will evolve in one way or another: From changing environments. Mutations. Possibly even genetic ...