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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31 views

Evolution of the reproductive drive?

At some point in the early earth the right mix of biochemicals combine to form to first organisms(or maybe they came on a meteor). Regardless, I would assume the original unicellular organism did not ...
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Are there examples of animals being sexually attracted to another species more than to their own?

I just thought that from the perspective of a female domestic cat, a male bobcat probably looks like the archetype of a perfect mate. As tall, strong, muscular and mighty as it possibly gets. Clearly ...
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Laurasia and Gondwana [on hold]

The Cambrian explosion was 540 mya. Laurasia and Gondwana didnt collide until 330 mya. So for 210 million years the land was divided into two large continents. Plants and insects had already colonized ...
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The selfish gene; why do we care about the well being of other species? [closed]

I am mid-way through Dawkins' book along with my new sapio-bromance with Robert Sapolsky. I have been wondering how you can settle on discrediting Group Selection in that we don't do anything for the ...
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Is there a system biology approach to compare pathways or famillies of proteins from an evolutionary point of view for the same organism?

I would be interested to know if there is a method/analysis or a set of methods to compare two groups of pathways or families of proteins. I would specifically be interested by a system biology ...
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regarding evolution of ears and sense organs [closed]

How could we(or any other organism) have developed ears through evolution when before having ears we did not know that sound waves existed or there was anything such as hearing? How did the first ...
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Probability for a megafauna specimen to exhibit a gene not present in either parent

What is the rough probability for a megafauna specimen to exhibit a gene not present in either parent? I'm looking, ideally, at the chance for one specific individual to be the first in a breeding ...
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Estimate for number of genes changed in speciation between a megafauna parent and child species [closed]

At least in terms of a back-of-the-envelope calculation, what is a believable range for the number of gene changes between parent and child species to represent speciation between species of megafauna?...
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Did the first cell self-replicate or was it multiple first cells? [on hold]

We're almost sure by now that the first cell was born in a some kind of underwater vents environment which harvested all the necessary conditions for it to exist. However, did the first cell self-...
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Why do death cap mushrooms not warn of their poison?

This has been puzzling me for a long time now. There is an evolutionary predilection for living things which have evolved strong defensive measures (that may not themselves be visible) to give ...
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What's the evolutionary purpose of having hearts?

According to this New understanding of heart evolution Humans, like other warm-blooded animals, expend a lot of energy and need a lot of oxygen. Our four-chambered hearts make this possible. It ...
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Phylogenical differences with nuclear and mitochondrial DNA

This is a textbook question, I would like to verify my answers. According to the textbook it is possible to construct a phylogeny using nuclear and mitochondrial DNA and these trees to be different, I ...
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Did our late Cryogenian ancestor have a heart?

If I'm correct, our Cryogenian selves might be somewhere between the Urbilaterian and the Protostome-Deuterostome ancestor (many age estimates of PDA here). Reconstructions of the former's anatomy ...
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Why are ducks more cautious than pigeons? City park paradux

In my city park there are mostly two types of bird: -Mallard duck -Rock dove (pigeons) When I feed pigeons, they approach me very close. Sometimes they peck the food that fell on my feet. If I hold ...
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creating life in the laboratory [on hold]

Originally life came about through non life but Scientists are unable to achieve this in a laboratory . Why is this ? Is it the time factor ? I believe that it took one billion years for life to ...
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How much DNA do humans share with their first non human ancestors? [closed]

As far as I understand, by reading this Hominini Australopithecus , our last ancestors are one of the australopith species evolved into the genus Homo. By taking DNA sample of bone fossils it's been ...
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Is bacillus strain 2-9-3 really 250 million year old?

I've read that in the last decade (I believe) some scientists discovered a microorganism, which they dubbed bacillus strain 2-9-3, in a crystal of salt that they think is 250 million years old and ...
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How hard would it be to create a protein “by chance”?

I just read an article about David Gelernter, who was arguing against Darwin's theory of Natural Selection. He said one particular thing which stood out to me: "...how hard it would be to create just ...
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Standard textbooks to complete a comprehensive undergraduate degree in biology [duplicate]

I am a graduate student of mathematics, with an interest in ecology and evolution, and would like to learn undergraduate biology, at the level at which it is taught at one of the top 30 schools in the ...
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Species specific White Blood Cells (WBC) composition

In our ongoing immunology undergrad course I learnt that neutrophil primarily fights off bacterial infection and lymphocyte is produced in response to viral infection. I also learnt that neutrophil ...
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Why have plants evolved to photosynthesize glucose instead of another molecular compound?

I think this question can be broken down into two sub-questions: Why do plants produce $C_6H_{12}O_6$ as opposed to another molecule following the formula of $C_nH_{2n}O_n$? Why not $C_8H_{16}O_8$, $...
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Is it reasonable to assume selection for an observed change? [closed]

Assume a gene G plays a role in regard to factors A, B, C and D. Factor A is important on a daily basis. Factor B is important on a hourly basis. Factor C is important on a yearly basis. Factor D is ...
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Why isn't the human zygote considered a human life how is a living anatomically modern human defined biologically? [on hold]

It has 46 chromosomes by default when healthy(Differences almost always are pathological) and has almost every biological functions, processes a Newborn or and Adult person has. It even invades ...
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What is the function of spongin in sea sponges?

Sea sponges (Porifera) use different types of skeletons to support their structures. Some skeletons are built from minerals, some are built from proteins like spongin, and some use both. My question ...
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Evolution in Biology Species [duplicate]

what a species is, why it is so difficult to define, and how we should best determine the boundaries between species. This is the basic general definition: A species is often defined as the largest ...
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Knee directions

art student with very little knowledge of biology here. I was thinking about the designs of mythical creatures and I got stuck on the topic of knee directions, and couldn't work out the appropriate ...
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The Evolutionary significance of Coelom [closed]

What is the evolutionary significance of coelom formation?
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Are there any known plesiomorphies of all living mammals relative to a newer trait state in all living reptiles?

If I understand how a "trait" is defined, a turtle's shell is a synapomorphy relative to mammals and the common ancestor of living amniotes. The same would go for a snake's limblessness, etc. But are ...
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Is there a name for survival of the fittest in a single family? [closed]

Imagine a case where the children of a bird each have a 50% chance of being born blind. But the bird always has on average 4 chicks. So on average 2 will be blind and 2 sighted. (Perhaps this could ...
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What are the evolutionary reasons behind men being taller than women?

Human men and women are sexually dimorphic: there are some phenotypic differences between men and women. Men being taller than women is an accurate stereotype. Overall, men are on average 13 ...
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Why has reproduction evolved as a choice? [closed]

From an evolutionary perspective, the purpose of an organism is to pass along its genes through reproduction. However, as humans we have a choice if we want to reproduce or not. The good feeling from ...
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Is the Lucy fossil really what scientists claim it is?

The New Scientist has an article talking about how a baboon bone was found in the Lucy skeleton. Creationist sites like this, https://christiannews.net/2015/04/23/evolutionary-embarrassment-part-of-...
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Do Traits Have to be Adaptive in Order to Survive?

I'm reading Michael Pollan's book 'How to Change Your Mind', which is largely about psychedelic mushrooms. In discussing the biology of the mushrooms, he writes: 'Even if psilocybin in mushrooms ...
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Why was the evolution of large, slowly reproducing organisms preferred?

One of the very basic facts that Darwin pointed out was about the life span of organisms. Organisms with smaller lifespan reproduce quickly and hence variations are produced faster. This helps in ...
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If coelocanths are more related to humans than groupers -does a Coelocanth's DNA literally have more sequences in common with a human than a grouper?

Would a coelocanth and a human still have more sequences in common than a coelocanth and a grouper? Would the coelocanth and human dna basically "look" more similar than either would to a ray-finned ...
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Evolution experiment for kids?

What would be a good plant to show the process of evolution to a small kid? Obviously it's a long term experiment, and preferably a fruit or a veg that is edible (like tomato?), and what ...
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Have humans evolved to live longer?

Do people live longer only because of better hygiene, medicine, society etc or also because they're slowly evolving to live longer under same circumstances?
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Schizocoely and Enterocoely

In terms of phyla, mollusca, annelida and arthropoda are schizocoelic, whereas echinodermata and chordata are enterocoelic. I know that their difference lies in the formation of the coelom but how ...
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Why are mammals the only animals with pinnae / outer ears?

Yes, I know owls have feathery "ear tufts", but these are less suited for hearing and more for display. And I find it hard to believe that animals like dinosaurs or other cursorial archosaurs would ...
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Finding genotype/allele frequencies of second generation in Hardy-Weinberg equilibrium given that the recessive allele is deleterious [duplicate]

A population in Hardy-Weinberg equilibrium has p=0.6 and q=0.4, and allele q (recessive) is deleterious. If 25% of heterozygous individuals and 50% of homozygous recessive individuals die before ...
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Evolution of the haplo-diplontic life cycle

From wikipedia > Biological Life Cycle: haplontic life cycle - the haploid stage is multicellular and the diploid stage is a single cell, meiosis is "zygotic". diplontic life cycle - the diploid ...
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What was the cause of some egg-laying animals evolution to animal-laying?

Is there a specific reason for this evolution? Are no egg-laying animals more complex beings so their embryonic development requires more time and better nutrition conditions?
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Non-hair synapsid integument

Anybody noticed that mammal skin (both with hair and without hair) has an irregular scaly pattern when seen up really close? If so, may it have been retained from its pelycosaur and even reptiliomorph ...
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What’s the evolutionary benefit of cats playing with their prey?

I just saw a cat playing and teasing a wounded bird for minutes, and I immediately started to wonder what the evolutionary rationale were. After all, it seems eating the prey as soon as possible ...
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Any arthropod with non-sprawling limbs?

Are there arthropods with semi-erect or erect limbs? If not, could it be because of interference between more than four limbs or any other constraint?
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Why do we find flowers attractive?

Given that we (humans) are not evolutionarily closely related to bees, why do we find flowers attractive?
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What problem does the Dobzhansky-Muller Model resolve?

This page describes the Dobzhansky-Muller model and I can follow the illustration of the split leading to incompatible hybrids. But at the start of the page the author states "[Dobzhansky and Muller] ...
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Why are worms, centipedes and snakes long?

Some animals have mostly distinct, non-repeating body parts, each performing a particular function. However, some kinds of animals, such as worms, centipedes and snakes, have a long body that appears ...
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Has anyone confirmed Darwin's theory that nectar began as something “injurious” to sap?

In "Origin of Species", Darwin says (I have added bold for emphasis): Certain plants excrete sweet juice, apparently for the sake of eliminating something injurious from the sap: this is effected,...
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Can you find the amount of heterozygotes in a pop. from the phenotypes shown in the pop [duplicate]

I know the hardy Weinberg equation but that is for the amount of alleles not the amount of phenotypes. So if there are 600 black(dominant) organisms in the population and 400 green(recessive) ...