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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Homology of front limb and hind limb in Eusthenopteron, femur homologous with ulna?

Homology by ontogeny is a topic where debates happen every now and then. The talus for example, from tibiale, intermedium, centrale, or a combination of those. Also, the homology between the zeugopod ...
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When telomere length is measured, is the method performed on a collection of cells yielding an average?

What are the methods used in measuring telomeres in human or animal subjects? Can it be done on an individual cell? Has the following concern been raised and addressed before: What if there exists a ...
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The Fish-Tetrapod Transition, evolution of the “elbow” in Stem Tetrapods

The Acanthostega and Tulerpeton limbs seem to form "elbows" in an axis perpendicular to the flexor and extensor plane of the fin. They seem to "flex" their "elbow" ...
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Sprawling locomotion, are knee/elbow joints perpendicular to erect locomotion?

The first terrestrial animals used sprawling locomotion. Is the knee and elbow jointed perpendicular to the joints in erect locomotion? It is easy to assume so, based on how the limbs move in ...
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How have humans adapted to the decrease in binding affinity of haemoglobin?

I am writing an article based on human adaptation and I would like to know how humans have adapted to a decrease in the binding affinity of haemoglobin, more like how have humans evolved with this ...
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How can we estimate how many generations have passed between two individuals?

I am taking a course in Bio Informatics, but my biology knowledge is pretty limited. So a question raised for me. Let's suppose we have a pair of aligned sequences, how can we estimate how many ...
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If sexuality is genetic, how did asexuality evolve?

If sexuality is genetic, then it stands to reason that evolution would strongly favor people who have children. In other words, heterosexuality & bisexuality should be favored, while homosexuality ...
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Hardy Weinberg equilibrium problem with no heterozygous mating

In a diploid population of A1A1, A1A2, A2A2, the A-locus was initially in H-W equilibrium. Due to certain changes in the mate choice pattern, heterozygotes completely stopped mating with each other (i....
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is there a discontinuity after the Cambrian period?

im not a biologist, just a big fan of biology and sorry if it sounds too dumb if the Cambrian period is the proof that Darwin's theory of evolution is wrong (stephen meyer claims this, and offer an ...
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Could a mutation on neutral part of genome become deleterious?

I know that silent mutations are neutral because they dont affect function of the protein/gene, and a missense mutation would. But lets say both occur on a neutral portion, could one or the other ...
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Reproduction in animals

Humans have acquired knowledge about their environment through many observations. Today, humans have wide variety of resources to gain knowledge about reproduction in human beings and other ...
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How many times did photosynthesis evolve?

Was it a 1 and done thing? Plants seem to have developed photosynthesis by the endosymbiosis of cyanobacteria. Is the latter the one time in Earth's history that the process independently came about? ...
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Which fish did modern tetrapods descend from?

Did modern tetrapods descend from Tiktaalik or Ichthyostega? While I understand that in terms of all tetrapods, the lineages of Tiktaalik and Ichthyostega both would be included, but I want to know if ...
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What terrestrial Gastropod (specifically snails) has the fastest reproductive rate?

I am looking to do a series of experiments to test the adaptation of snails to different environments (Controlled environments in a lab setting. No organisms would be released into the wild under any ...
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How did Rna replicate according to Rna World Hypothesis?

I was studying Rna World Hypothesis in Khan Academy, and there is a line..... The RNA world hypothesis suggests that life on Earth began with a simple RNA molecule that could copy itself without help ...
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Why is this the equation for the fitness of cooperators?

This paper gives the equations as: The fitness of cooperators and defectors is respectively given by fC = b(i − 1)/(N − 1) − c and fD = bi/(N − 1). c - cost b - benefit i - number of cooperators N - ...
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What is the definition of gene, genotype and phenotype, pre and post DNA?

i know that the definition of gene is a unit of heredity, also a sequence of nucleotides in DNA that gets copied to RNA and then proteins. Genotype is the genetic composition of an individual ...
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Has the human capacity to heal from burns evolved due to actual burns throughout human history?

I just burned myself while cooking, and it occurs to me that although this has happened countless times, my skin always heals itself rather well after burns. In this post I make various assumptions/...
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Is there anything wrong with this objection to evolution? [closed]

My friend's argument against evolution goes like this: It is extremely unlikely that life as we know it evolved from a random mutation process because every organism is like a machine, in that one &...
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How did migrations evolve?

Disclaimer: I know nearly nothing about biology. I was wondering how did the migratory behaviour of birds evolve. Assuming that evolution/natural selection works slowly and gradually (at least most of ...
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What is the evolutionary advantage of breathing and heart beats syncing between partners?

I recently read that partners who are close to one another usually when touching have their heart beats and breathing in sync. Why does this occur? What is the benefit of it occurring? How does this ...
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What keeps mitochondria from multiplying out of control?

What keeps mitochondria from multiplying out of control and killing the cell? According to endosymbiotic theory, mitochondria were once free-living bacteria that got ingested but not metabolized by ...
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What is the common ancestor of humans and trilobites?

I have always been immensely fascinated by trilobites. What is the single common ancestor of humans and trilobites? Do we know? Do we have a name for it? Have we identified it?
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Species that have evolved to be near identical? [closed]

Are there any species that are near identical in outward appearance but are separate species? When I say species I mean can’t interbreed.
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Why is the null hypothesis of trait evolution Brownian motion?

Many models of continuous trait evolution assume that traits evolve according to Brownian motion. What is the biological or physical basis for this choice? I realize there are models that do not ...
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Is Panmixia very rare?

I'm reading the wikipidia page on Panmixia. Panmixia (or panmixis) means random mating. A panmictic population is one where all individuals are potential partners. This assumes that there are no ...
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What is the process of aging exactly? [closed]

Getting old Hello community, I have been thinking about age, and I thought that aging is the reverse of how a biological system is able to fix itself over time. Actually, some species actually are ...
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Narwhal tusk evolution

I was reading about whales and wondered why did only narwhals, among all other species of whales, evolve to have tusks? Is there a specific environmental reason, for example something unique about the ...
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Did the jackal (wild African dog) evolve independently or with some form of human domestication?

The jackal is a wild dog species in Africa that feeds on carrion, much like the hyena. Pop science, as it were, would make us believe every dog species emerged as a result of human domestication. Was ...
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Evolution of Heteromorph Ammonites

I was reading about fossils and thought of this question: what was the purpose of the shells of heteromorph ammonites (for example, ammonites of the genus Nipponites)? Wouldn’t the odd shapes of these ...
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How do crickets get away with being so loud without getting eaten?

How do crickets get away with being so loud without getting eaten? There are a number of bugs that reproduce by blatantly advertising their location. For instance fireflies advertise their location ...
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Why are some organisms able to regenerate?

Why can sponges, cnidarian polyps and planaria regenerate if broken up, but other animals e.g. humans and phylum chordata cannot?
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Adaptive radiation vs divergent evolution

What is the difference between divergent evolution and adaptive radiation? People have Said different things Divergent evolution is when species from a common ancestor evolve differences by adapting ...
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Question relating to gradualism

Is phyletic gradualism and gradualism essentially the same thing I just saw the term phyletic gradualism and I was wondering
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Are coronaviruses gaining an evolutionary advantage?

So there are 7 known strains of coronavirus that are known to infect humans: 4 that cause the common cold (229E, NL63, OC43 and HKU1), and 3 that have been known to cause acute respiratory infection (...
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Why do we have to move in the cold for higher chance of survival?

To survive in the cold temperatures, a person should move as much as possible so that they do not freeze to death. But constantly moving also leads to the body becoming more and more exhausted. Why ...
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Why didn't more muscles evolve the endurance of heart muscle? [closed]

The heart is a muscle capable of both the quick contraction of white muscle cells, and also the endurance of red muscle cells. Why haven't more muscles in the body adapted the same combo of abilities? ...
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Can bacteria (dis)assortatively mate?

After revising some evolutionary concepts, I stumbled on the "big five" of evolution (e.g., mutation, selection, mating, genetic drift, gene flow). I wanted to understand if mating as in &...
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Expected number of SNPs in a sample of size `k`

Consider a Wright-Fisher population of constant size N. We sample k haplotypes in this population. What is the expected number ...
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Do uerotelic organisms save roughly 3/4ths water compared to ammonotelic?

My analysis based on Daniel Atkinsons work, professor in biochemistry (see references below), is that ureotelism is saving 3/4ths water compared to ammonotelism. Is this correct? What do people here ...
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Why are fatty acids synthesized in two carbon units?

Why does long-chain fatty acid synthesis involve the two-carbon precursor, malonyl CoA, rather than the one-carbon acetyl CoA (or even a three-carbon precursor). Is this because fatty acids with an ...
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Why do the two sexes have different reproductive costs and capabilities?

Is there an evolutionary explanation that shows why the reproductive costs are mostly on the female sex? And therefore, why do males can potentially have more offspring? Does that happen to create ...
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What is the evolution metaphor about water flowing downhill?

As part of my biology undergrad degree, I took a course on the Origin of Species, where we read Darwin's book and also several other readings about the origins of evolution. I recall that during this ...
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Role of epigenetics in evolution and transmission of defects caused by drugs

In a documentary, they were saying that epigenetics changes caused by the environment in an individual can be transferred to the following generations. I have some questions on that: How many ...
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Why don't the female lions in a pride help their male lion to protect their children from other males?

I watched a dozen of videos taping the fights between male lions; none of them involve female lions assisting in the fight. It is also known that the male lion who take-over the pride will kill all ...
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Why humans didn't evolve to safely consume rotten food? [duplicate]

I'm not a biology person at all so please forgive me if my question is silly. I was just wondering that why didn't evolution cause us to digest, without issues decomposed food?
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Why do mammals rarely have eyespots?

An eyespot is a marking to mimic the eyes. Many examples of eyespots can be found in fish, reptiles (including birds), and insects. Recently Radford 2020 has shown that artificial eyespots can reduce ...
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The Proofreading Function of Coronavirus Polymerases

I have heard that the Coronavirus family have a proofreading and editing function in their polymerase enzymes which can recognize and excise mutations. This is obviously disastrous for the population ...
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Shrinking size of Y chromosomes

I read on the web that the size of Y chromosomes decreased in earlier period of time and the picture below tells that it is still occurring. So basically I want to know what caused this shrinking and ...
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Evolution: what were we doing for 100.000 years? [closed]

I'm not a biologist/anthropologist but there is a question that comes up again and again and which I couldn't find any deeper thought, even not a speculation. As far as I understand it, according to ...

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