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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28
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3answers
8k views

Does animal blood, esp. human, really have similar salinity as ocean water, and does that prove anything about evolution?

It is an often-repeated claim that human, and in fact all animal blood is salty because we evolved from aquatic organisms, and that blood has a similar concentration of salts as ocean water, or at ...
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1answer
523 views

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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Definition of Species in accordance to biology [duplicate]

I am confused regarding something my LS professor said in class today and about what my batchmate brought up. Teach said that 'interbreeding must occur in nature' (and not in a lab) for two species to ...
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1answer
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In evolutionary history, which came first - neuron or astrocyte?

As research is showing astrocytes role in information processing [1], I am interested in knowing which evolved first - an astrocye or a neuron ? [1] Santello, M., Toni, N. & Volterra, A. Astrocyte ...
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8answers
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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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1answer
31 views

What insect/invertebrate species evolves fastest?

I am starting an experiment in which I will be forcing evolution in a moderately complex species of insect or invertebrate. I am prepared for the possible longevity of this experiment, but i have no ...
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Humans Evolved to Live Longer than They Could at the Time

Why and how did humans evolve to have a lifespan that was longer than that was actually 'achievable' in the conditions through which we evolved? I'm not saying ('recent') evolution is the cause of the ...
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Is modern medicine selecting for weaker immune systems?

I know that sometimes genes are selected against if it becomes evolutionarily useless for example in humans with respect to our vitamin-C-producing enzyme GULA due to us getting plenty from our diet. ...
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2answers
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Why isn't speciation a negative feedback loop?

To rephrase my question more articulately: Speciation begins when two groups within a species starts to become reproductively isolated, and is complete when the two groups can't interbreed (for the ...
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0answers
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Collared doves compared to wood doves [closed]

I have observed that wood doves are more quiet than collared doves. Here you can see the difference between the two dove types: https://www.youtube.com/watch?v=4s47XcDbcq0 The thing is that collared ...
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What is the current scientific consensus regarding the relationship between Eukaryotes and Archaea?

In the traditional 3-domain system, the domains Bacteria, Archaea, and Eukaryota are all distinct from one another, with the latter 2 usually being sister-groups in a clade. However recent evidence ...
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1answer
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Why might long telomeres be selected for in laboratory mice?

In a recent episode of The Portal, Eric Weinstein sits down with his brother Bret Weinstein to discuss Bret's Reserve-Capacity Hypothesis. It's an incredible story of scientific discovery and academic ...
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1answer
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The evolutionary advantage of sending the most fearless to the front

Let species A be prey to another species B. Assume that predators B only attack isolated individuals A (because they are afraid of larger groups of A's). So it is good for species A to be on the way ...
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Why do pandas have a high probability of giving birth to twins?

According to the BBC documentary "Wild About Pandas", about half of panda birth result in twins. Why do they have such a high probability compared to other mammals? What factor(s) control that ...
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1answer
65 views

What factors have led to selection for intelligence in crows and rooks?

The Corvidae family could include some of the smartest species after primates. What could be the factors that differentiate them from other species of birds that have determined their potential for ...
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0answers
39 views

How does natural selection interacts with sustained mask use?

At leasts in some European countries, the number of respiratory (non-covid) infectious diseases on children this term is higher than last year and similar to pre-pandemic years in spite of social ...
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1answer
106 views

Balancing selection vs introgression?

Balancing selection can maintain polymorphisms in natural populations for extended periods of evolutionary time. However, in this paper, Dannemann et al. 2016 identify three archaic haplotypes in the ...
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0answers
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Evolutionary reason green bottle flies are shiny

Just noticed some green bottle flies in my backyard. They are shiny. A shine like that attracts attention (of potential predators) and probably takes some work to maintain. This made me wonder why ...
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0answers
60 views

Is there a functional reason why the right side of the heart has a tricuspid valve while the left has a bicuspid one?

Is there a functional reason why the right side of the heart has a tricuspid valve while the left has a bicuspid one? Why is it necessary that the right atrioventricular valve be 3-cusped?
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0answers
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Is there an evolutionary advantage to bees to becoming docile when exposed to smoke?

I have not seen other research on this on line, it occurred to me though that this physiological behavior / stimulus-response of bees (calm down when exposed to smoke) might be a subject for original ...
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1answer
201 views

Are there evolutionary advantages for the bee sting to kill the bee?

The question title says it all: are there advantages for the sting of a bee to kill the bee? It seems to me getting rid of this would have only advantages, and might've been selected for if a mutation ...
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2answers
102 views

Is there any species of mammals where males can feed the offspring with milk?

It seems to me that an evolutionary path where not only females, but also males could feed the offsprings is entirely plausible: the males anyway have niples, so it is easy for the offsprings to ...
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9answers
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Why do plants have green leaves and not red?

I know plants are green due to chlorophyll. Surely it would be more beneficial for plants to be red than green as by being green they reflect green light and do not absorb it even though green light ...
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0answers
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Is there a single protostomate common ancestor that has pseudocoelomate structure?

I think about 15 years ago I saw a new classification system that placed Plathyhelminthes worms with Annelids and Mollusks into a superphylum (or other systematic clade) Lophotrochozoa, while ...
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1answer
112 views

book on human sexuality evolution

i am interested in Lynn Margulis' book Mystery Dance: On the Evolution of Human Sexuality. i don't find it in libraries and it's too old and i am too poor for paying 20 euros for a 1991 book. Does ...
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1answer
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Multicellular but uninucleate?

The "standard" biological setup is one cell-one nucleus (with one or more chromosomes and zero or more plasmids). Multinucleate cells are a thing (e.g., in fungi)--a situation wherein a ...
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1answer
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How old is the Pogona genus?

What it says on the title, how old is the genus Pogona, which includes all bearded dragons? I tried looking online, and all I got was the useless answer of “bearded dragons are descended from their ...
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1answer
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Why are apes so poorly adapted for walking upright?

Non-human apes are quite poorly adapted for walking upright, in terms of their anatomy. I have found many sources that explain how their anatomy is so unsuitable for an upright life, yet none have ...
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In the absence of natural enemies, does evolution eventually create natural enemies?

I wonder if there is experimental evidence on this (either from computer simulations or perhaps cases of isolated species like on the Galapagos Islands). Imagine the hypothetical situation of a group ...
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0answers
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Can a less fit strain of a virus impose over a fitter one? [closed]

According to this link, the Dominant Delta Variant may mutate itself into destruction. The Delta variant in Japan was highly transmissible and keeping other variants out. But as the mutations piled ...
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Evolutionary pressure of vaccines towards a virus

I am trying to understand the following quote from one of the Twitter threads : A change in the spike protein which allows the coronavirus to enter and infect human cells that is radical enough to ...
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2answers
170 views

When is it better for a gene to cause a biased sex ratio?

Because genes are selfish and want to maximise their transmission from generation to generation, if they can distort a population's sex ratio, isn't it always in their interest to cause a biased sex ...
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Can antibiotic resistance cause problems for the microorganisms producing them? [duplicate]

My understanding is that antibiotics are naturally produced by microorganisms as a defensive measure against certain kinds of bacteria. For example, some Penicillium molds produce penicillin. Clearly, ...
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2answers
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Are there any animals that get smaller as a normal part of their life cycle?

It seems that at any given moment in a creatures life, it either grows bigger or has stopped growing. The only exceptions I know of are extreme events like insects undergoing metamorphosis or ...
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1answer
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Are phylogenetic trees from sequence data assuming neutral evolution?

phylogenetic trees built from DNA/protein sequences use sequence differences between these biological sequences as proxies for relatedness. More specifically, maximum-likelihood phylogenetic trees (...
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1answer
629 views

What do blue cone cells add to visual function?

First of all, I saw this other question in the SE sites with a good answer, but I didn't find an explanation about the blue cones specifically. So most human beings have 3 types of cones (cells ...
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0answers
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How have some cancers "evolved" to be so aggressive and treatment-resistant?

[In this post, I may ascribe agency to processes, inanimate objects or microorganisms: this is rhetorical, I know they don't "intend" anything. I will also use "evolution" in a ...
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1answer
55 views

For animals with separate hermaphrodite and non-hermaphrodite populations which is more common, female + herm or male + herm?

I think the question already says it all. I know there exist animals that have both herm and female populations and other's with herm and male populations, I'm not personally aware of any animal that ...
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0answers
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Is the principle of "the least energy" a fundamental principle of evolution? How does it stand with the rule "the one who replicate the most"? [closed]

The principle of "least energy" seems to be a fundamental law of the universe (is it?). I probably use the wrong word. I'm just talking about the reason why electrons are filling first the ...
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2answers
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Why do animals with more mass tend to have brains with so much more mass when it seems like a similar mass brain should be able to do the job?

Why does a wolf have a brain so much bigger than that of a poodle, when a poodle's brain is big enough to do the job, I would have thought. Likewise, if tigers are not smarter than house cats, why do ...
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0answers
48 views

Measuring innate caring about offspring and long term surivavability

I am not a biologist, and don't have much technical knowledge of biology. That being said, having observed the real world, it seems that, at least for mammals, human beings seem to "care" ...
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2answers
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Does using the human genome as a reference influence the chimpanzee genome's similarity to the human genome?

It is often stated that human and chimp genomes are 98% similar, e.g. this is included in an article on the American Museum of Natural History website. I also see in the release notes for the NCBI ...
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1answer
199 views

Book recommendation: Modern Synthetic theory

I'm a zoology minor. I wish to study modern synthetic theory (evolution) is there a good book available online for reading? The book should cover a basic idea about what the elements of modern ...
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Connection between triploblasty and bilateralism

Looking at the phylogenetic tree for animals, it appears that animals evolved bilateral symmetry around the same they evolved three tissue layers (triploblasty). Is there a reason why three tissue ...
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2answers
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Is there such a science in which the knowledge of biological processes (e.g., evolution) would be mathematically axiomatized and inferred (deduced)? [duplicate]

There is the following Mathematical Challenge Twenty-three Mathematical Challenge Twenty-three: What are the Fundamental Laws of Biology? * This question will remain front and center for the next 100 ...
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2answers
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What terrestrial trait makes cetaceans so successful in an aquatic lifestyle?

Intuitively, I would expect that an organism that has lived in the ocean for millions of years and can breathe underwater should outcompete any newcomer that is not fully adapted for oceanic life. It ...
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1answer
33 views

How big does a landmass have to be in order for biota to not undergo island dwarfism or gigantism?

Somebody asked it here, and the answer was basically "there's no specific size". Still, I'd like to ask if there's an average size to it. Would a Greenland-sized landmass cause elephants to ...
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0answers
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Evolutionary advantage of the nutrient played by the chicken [duplicate]

What is the evolutionary advantage of the chicken throwing out so much nutrient ovulating all the time? Is there a clear advantage to this? Chickens ovulate all the time for the same reason human ...
7
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1answer
95 views

How related are trees?

I was surprised to see how far apart macadamia and hazelnuts are from each other. I always thought all trees had a common ancestor that was also a tree. But that doesn't seem to be the case? Did wood ...
72
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4answers
8k views

Why are there no wheeled animals?

In physics, "almost everything is already discovered, and all that remains is to fill a few unimportant holes." (See Jolly.) Therefore, on Physics SE, people are veering off into different directions: ...

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