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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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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Is there any evolutionary advantage of selection of L-amino acid over D-amino acid?

After listening to a scientific talk, I had this question that why in the natural selection process, are the L-amino acids selected over the D- form. However, we still we produce D-amino acids; ...
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Why are there nail growth differences between humans and other mammals?

When a cat is growing, his nails are growing with him to some extent. A grown cat has a fixed nail length that is not extending. By contrast, human finger nails just keep on growing, so we have to ...
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Why is chlorophyll green? Isn't there a more energetically favorable color? [duplicate]

Chlorophyll being green means it absorbs light in the red and blue area of the spectrum. Isn't this the high and low energy light? Wouldn't plants get more energy if they absorbed light in the green ...
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Why do some plant species have lobed leaves, while similar species in the same habitat don't?

Some plants have lobed leaves, like the English oak (Quercus robur), while other plants growing the same deciduous woodland habitats, and very often growing alongside oaks, such as the European beech (...
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Can we make a rough estimate of the number of generations since the origin of life?

According to what we've learnt : we can approximate the number of generations since the first human pretty much like us (depending what / who we talk about). we have an idea of the series of life ...
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Is there any evidence that a virus can modify human evolution

I was just reading Evolution of lactose tolerance, and in it one line says "But there was a time in human history when our diet and environment conspired to create conditions that mimicked those of a ...
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In which order did the cells of the immune system evolve?

Thinking about how complex the interactions between different types of immune system cells (T-helpers, T-Killers, Phagocytes, B-Cells etc.) are, it's fascinating how they all combine to get the ...
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Is there any recent evidence for the aquatic ape theory of human evolution?

The aquatic ape theory suggests that many features that distinguish humans from their nearest evolutionary relatives emerged because the ancestors of humans underwent a period when they were adapting ...
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Online phylogenetic tree of human lineages

I am looking for a source of information about the diversity of human lineages and their relationships. With a quick google search it is easy to find this type of tree A perfect online resource ...
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Is there an evolutionary advantage to crying when sad?

It seems as though the act of crying when sad does nothing to relieve that sadness. Is there an advantage to crying from an evolutionary perspective, or is it the end result of a different process? ...
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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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Why, specifically, does each generation, on average, improve upon the design of the species rather than degrade it?

In every non-life example I can envision, a copy of a copy is always a degraded or less pure version of the original unless some outside influence acts to correct the copy back toward the ideal ...
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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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Why does the butterfly have a cocoon stage in its life cycle?

Why does the butterfly have a cocoon stage in its life cycle? It could have simply grown up within the egg/cocoon, and emerged as a butterfly. Instead it is first an egg, then a worm, then a chrysalis,...
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Why are there so many medicinal plants?

Question Quite a few plant species can be used for medicinal purposes wiki. As an example, Filipendula ulmaria is rich in acetylsalicylic acid (aspirin). An allele that produces a substance which is ...
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What was the reason for some plant and animals to become giant in course of evolution?

The dinosaurs, mammoths, giant plants etc are known to be bigger than modern animals. I wonder why they had been lived and why they are not living now? I really don't know much but is it something ...
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How did the first life form on Earth reproduce without DNA?

How did the earliest life forms exist without DNA? The most likely scenario I can think of for life happening from nothing is that, over billions of years, with trillions of water molecules and dust ...
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How did zootoxins evolve?

I've always wondered how toxins in certain organisms have evolved. Particularly, organisms that produce toxins as a deterrent to predators as opposed to organisms that use it to paralyze their prey. ...
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Was iron important for the first life on Earth?

Some ions or compounds are thought not to have become involved or important in the metabolism of living organisms until some time after certain mutations took place. For instance, early life is ...
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There aren't any animals like hornets that hunt large prey (like a rabbit, or even up to a deer), right? Why not?

There aren't any eusocial animals (hives of wasps, ants, termites, etc) that hunt large prey, are there? I'm thinking prey in the size range of, say, a rabbit, or even a deer. I can't see a rabbit ...
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Why are the Galápagos islands so special?

Why did Darwin formulate his theory of evolution just after his visit to the Galápagos islands? Why were they so special from an evolutionary point of view?
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Can any species be bred selectively/engineered to become as diverse looking as dogs?

I've done some research and it appears that dogs are the most diverse looking single species of mammals. The questions that interest me is - are dogs special in respect to genes/gene activation ...
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Why Did 6 Great Ape Species Survive But Only 1 Hominid Species?

My dad asked this question when I explained some circumstances surrounding Homo sapiens survival against all odds. We know there is only one hominid species left in the world, Homo sapiens. We also ...
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Why these 2 dots frequently occur in dog's eyebrows? Do it serve/served any advantage?

It has been wonder me, in spite of so-many variations in color-patterns in dogs; these 2 dots (1 on each eyebrow) remains frequently occurring. Dog-1 Dog-1 close up. this one has a white dot. ...
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Are there any scientifically based predictions or theories of future human evolution?

Reading this question of the stack exchange got me thinking. I believe human evolution is an ongoing process and will not stop. Are there any predictions/theories about the phenotypes and genotypes of ...
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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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Why do birches have a white bark?

Several species of the tree genres Betula have a white bark,especially when they are young. This is quite peculiar to trees - at least in central Europe; so I'm wondering if there is a ecological ...
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How does a tiny spider interpret/cope with gravity?

The Question: Does a tiny spider know that it is walking on a wall or a ceiling as opposed to the (horizontal) ground? Does gravity play a role in this knowledge? Further thoughts: I am interested ...
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Sequence evolution simulation tool

I'm looking for a tool to simulate sequence evolution given a specific mutation model and birth-death model. I'm aware of tools and packages like INDELible, Seq-Gen and PhyloSim, but they simulate ...
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Why does sexual selection evolve beautiful features?

I have a very raw understanding of sexual selection: Say a group of females of a certain species "like" some feature of a certain groups of males; by "like" I mean some behaviour that makes this ...
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Which sex has higher variance of reproductive rate in modern societies - male or females?

Who has a more varied reproduction rate in modern western societies - men or women? The average rate is the same of course, but I wonder which sex have higher variance - higher variance means that ...
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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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Why did a lot of common insects evolve such a thin waist?

Something that doesn't quite make sense to me is why lots of insects like ants, bees and wasps have a such a small petiole when it connects many major organs to the rest of their body from a suddenly ...
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Why are men stronger than women?

What are the evolutionary explanations for why women are physically weaker than men (on average), and is this difference adaptive? See figure one here. I suppose that something puts pressure on men ...
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Why is iodine used for metabolic hormones?

Iodine and related biological iodine-carrying hormones are phylogenetically very old, at least according to Wikipedia. Humans use iodine as a metabolic indicator, as do axolotls and apparently most ...
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Beginning of the urogenital system

Are any invertebrate nephridia (proto/meta) homologous with vertebrate kidneys in the sense that embryologically they also begin together with the genital system? When did the embryologic association ...
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Difference in length of Okazaki fragments

The length of Okazaki fragments in the lagging strand is about 100-200 nucleotides in eukaryotes and about 1000-2000 nucleotides in prokaryotes. What (molecular mechanism, enzyme type ) determines ...
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A question about the intersection of evolution and thermodynamics

From this 2014 article in Quanta magazine by Natalie Wolchover there is a quote from a physicist with an intriguing idea about evolution: “You start with a random clump of atoms, and if you shine ...
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What are the costs associated with carrying lots of genetic material

What are the costs (if any) associated with carrying lots of genetic material (Big genome size)? energy for copying? raw material for copying? space in the cell? Maintenance cost (matter and energy)?...
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What factors are known to affect evolution?

My understanding is that the possible mechanisms of evolution are: Environmental changes Cultural/mating preferences Population Immigration Genetic Mutation Am I missing anything? I've heard that ...
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Why do adult insects have 6 legs?

Apparently, there is an advantage to having 6 legs in the insect world. What is that advantage, if anything? Why would such an advantage exist for insects, but not for other, larger land animals? ...
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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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What is the modern state of the theory of evolution?

When I studied biology at my medical school, we used to learn topics around a century old: the famous Darwin's voyage on "Beagle" to the Galapagos Islands, the classical triad of his Theory ...
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Darwin's first sketch of a phylogenetic tree

Coming from Darwin's notebook this first sketch of a phylogenetic tree became one of the most emblematic image from Darwin's work. I have a hard time to read what is written on it. What is written ...
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Is it possible to increase lifespan through controlled evolution?

A few years back when I was reading The Selfish Gene by Richard Dawkins, there's this short passage where he theorizes about a way to achieve an increased lifespan through controlled evolution. The ...
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Is there an “evolutionary species similarity calculator”?

Is there a website where I can input pairs of species and get an "evolutionary similarity score"? E.g. (numbers are completely made up) Input: Chimp and Human, Output: 97% Input: Cat and Human, ...
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Septic Shock: I'll kill myself before you kill me

Most of the deaths caused by extracellular bacteria don't actually result directly form their action. Rather, it results from an overreaction of the immune system to antigens such as LPS and LTA (...
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Why do squirrels have twitchy bushy tails?

Whenever I see a squirrel in the woods, it is always the big bushy tail flipping around that gets my attention first. A pray animal with a big bushy flag calling attention to it's self seems to be ...
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Why do (almost) all energy carriers contain adenine?

Unlike this question which is specific to just ATP, this one includes all energy carriers. When thinking of common energy carrying molecules, I can think of Adenosine triphosphate (ATP), Nicotinamide ...

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