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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If coral didn't exist, would jellyfish not exist either? (Or vice versa)

Is the evolution of corals, sea anenomes and jellyfish intrinsically linked to the point where if say corals did not evolve, neither would jellyfish? Or vice versa.
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Is there a metric for “evolutionary agility”?

By "evolutionary agility" I mean how fast an organism can adapt to changes in the environment. I’d imagine that a population with more offspring and a shorter time between generations would ...
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Do we know what the earliest stages of integument like fur or feathers looked like?

From either fossil evidence or from developmental evidence, are there any models for what the earliest stages of the evolution of fur, feathers or similar structures like pycnofibres would have looked ...
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Did humans evolve the ability to swim? Or is it just luck that we are able to swim?

Many animals like ducks have evolved features to be able to swim. Even not so aquatic animals like a tiger evolved so that its feet can act as paddles. In humans I don't see any direct feature that ...
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Why does the sandalwood tree produce a fragrant oil?

Why do sandal trees produce fragrant oil? Is there any purpose for it? Is it to make it unpalatable for other herbivorous animals? If so, why do humans find the fragrance pleasing?
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Evolution: Can the genotype frequencies change, but the allele frequencies remain constant?

If a population isn't evolving because it's in Hardy-Weinberg (HW) equilibrium, then I know that both genotype and allele frequencies must stay constant. My question is, can evolution still not occur ...
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The significance of haplotype blocks

I looked up haplotype blocks in Google Scholar, and the results returned seemed to show that almost all the relevant articles were published between 2001 and 2009, with almost nothing since 2010. Why ...
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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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When life first formed in earth's ocean, was it salty yet?

Do we have any tangible proof, e.g. by studying fossils of primitive life forms, that during their time the ocean was already salty, and at roughly similar levels to today's, or on the contrary, that ...
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The fraction of the genome that is evolutionarily conserved through purifying selection is less than 10%?

I would appreciate help in understanding the meaning, logic, and, in particular, how to interpret the phrase: The fraction of the genome that is evolutionarily conserved through purifying selection ...
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132 views

Is natural selection actually random?

In the Theory of Evolution, two main factors take place: One is random, which are the different mutations that organisms' DNA suffer. This process adds genetic variability to a given population. The ...
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Tree-pest coevolution

Many trees first reproduce decades after germination. Many pests of trees reproduce in under a year. It would seem that the pests have an advantage in the evolutionary arms-race, as they can evolve ...
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How is knowledge about farming transfered between generations in farming ants

There are some varieties of ants capable of "agriculture", e.g. dairing ants farming aphids and leaf-cutting ants farming fungus. How is the knowledge about the techniques involved passed ...
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How do microbes spread from a small place to a very large place?

Bacteria are very small, so they cannot move very far on their own. Viruses cannot move themselves at all. So how does a specific type of bacteria or virus spread from a small place to a very large ...
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How does sleep prevent our eyes from drying out?

If we don't sleep for about 16 hours, our eyes start to get dry, and no amount of eye drops helps. You use eye drops and then you're dry 10 minutes later. However, after you've slept for 8 hours, your ...
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Examples of species whose extinct common ancestor is well documented?

If we follow the ascendence line of two closely related species we can build a "Theoretical" common ancestor, whose characteristics were inherited with few differences by the offspring. <...
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Why largest cats so much larger than canids?

It is striking to me that there is no dog-like creature larger than a wolf while there are at least two species, tigers and lions, many (at least twice and probably 3 or 4) times the size of the ...
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Why do we anthromorphize evolution and genes and nature?

Books sometimes says things "Our genes want us to have as many children as possible", or "Evolution wants the fittest to survive". But genes are not conscious entities who can want ...
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Are there real world examples of one way isolation between two populations?

I know that for two populations A and B, there are situations in which there is a two way exchange of individuals between the populations, and there are situations in which there is no exchange of ...
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Is it possible for a invertebrate to evolve features like that of a vertebrate or BECOME a being similar to that of a vertebrate? [closed]

Could a invertebrate, for this lets say, a centipede/millipede, evolve into something like that of Pikaia? or something similar? Just an invertebrate turning into something similar or what would look ...
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Is evolution the reason why water is colourless for our eyes?

Liquid water is transparent to most of the visible spectra, whereas it absorbs infrared. Similarly, the air is almost transparent to the visible spectra too. Could these be the reasons why our eyes ...
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Do viruses pickup new genetic sequences from the host cell?

Virus replication does not involve meiosis so the virus genome does not gain diversity from having two parents , so other than from mutation, do viruses obtain new genetic sequences from the host cell ...
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Are there animals that have evolved a resistance to human activity or encroachment?

There are countless sources, both peer-reviewed and popular, explaining how overuse and misuse of antibiotics is breeding a new generation of antibiotic-resistant "superbugs" such as MRSA (Methicillin-...
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Does epigenetics suggest there is at least some element of truth to Lamarckism?

I am not a biologist. But googling "epigenetics lamarck", I find many different opinions: For: Lamarck rises from his grave, Epigenetics: Lamarck’s Revenge?, Darwin’s theory ... is incomplete without ...
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Why is cannibalism not an evolutionary stable situation?

In the 'the selfish gene' Dawkins writes (page 109): "The reason lions do not hunt lions is that it would not be an ESS (evolutionary stable situation) for them to do so. A cannibal strategy would be ...
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Why is selection less effective in small populations than in larger?

I can understand that the genetic drift has a higher impact on smaller populations, but what does it mean for the selection to be less effective in small populations than higher?
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About what percent of mutations are not adaptive?

Many popular texts that discuss evolution and natural selection often mention that many (or most) mutations are bad (not adaptive). Have there been any studies on what the rough percentages are? (E.g....
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Are there known chains of beneficial mutations?

Are there known examples of chains of beneficial mutations? What I mean by that is a mutation that leads to a series of mutations occurring after each other over a relatively short period of time ...
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Century old trees and evolution

We always think of natural selection as occurring at the level of populations not individuals. how about century old trees where germline is being produced from constantly dividing cells. Are all ...
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Question regarding the number of alleles

Why is it that in biology we often say that a gene has two alleles? When we analyze allele frequencies (e.g. using Hardy-Weinberg Equilibrium), formulas are often generalized for two alleles of a gene....
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Is there any evidence that discards the possibility of an organism-aided evolution?

The theory of evolution of Darwin is mostly accepted nowadays, while Lamark theory has been abandoned. There are many experiments that show that experiences do not alter the genes or are passed to ...
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In what ways does the number of legs affect an animal's functioning?

After much research, I've only been able to find specific examples of leg-number's impact on locomotion and dexterity (and/or object manipulation). I feel as though there must be other ways it has a ...
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First neurotransmitter?

Cnidaria are considered to be the first phyla to develop a nervous system. Nervous systems having 1, 2 and three neurons are considered to have appeared first in Cnidaria, with 2-neuron nervous ...
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Why did we lose our fourth type of cone cell (in the eye)?

Most species of birds, reptiles and fish have four types of cone cells in their retina, thus they have four independent channels for conveying color information. They are: short-wave (S) cones: ...
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Why do humans have flat faces, as compared to chimps?

Apparently adult, particularly older human faces resemble infantile chimps more tham they resemble any other adult hominid. And adult humans even have as many body hair follicles as infantile chimps. ...
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Recommended books and articles on the origin and evolution of sexual reproduction? [closed]

I'm interested in learning about the origin and evolution of life on Earth. In particular, one topic that puzzles me a lot as a layman is the evolution of sexual reproduction, since the DNA mutations ...
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Are there computational models verifying the feasibility that complex biological systems can emerge by random mutations plus natural selection?

I am interested in studying the theoretical feasibility that very complex systems such as the vascular system, the respiratory system, the nervous system, the digestive system, among others, could ...
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Can DNA be used directly to determine the age of a mutation?

I've studied that proteins found in a sample as biochemical evidences for evolution. Its variation in structure and configuration can be used to date the age when that mutation occured, effectively ...
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Is there a bacterium that became a virus?

Is it possible for a virus to be a descendant of a bacterium that was not through horizontal gene transfer? How I think this could happen: Suppose a species of bacteria lives in an environment where ...
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Why animals haven’t yet evolve in 2020? [closed]

In past when I was born like 1990s I notice most animals haven’t evolved in 30yrs. Example cats haven’t gain more muscular body as to be strong to defend themselves from predators like well many ...
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How would evolution explain parastitic wasps? [duplicate]

I read this article about wasps that can do "brain surgery" on cockroaches. https://www.wired.com/2014/02/absurd-creature-of-the-week-jewel-wasp/ How does evolution create such a thing? The brain ...
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Why such diversity in sexual dimorphism in passerines?

In searching for info to answer my question, I’ve found a fascinating 1998 article by Owens and Hartley from Proc. R. Soc. Lond. B. It reports such cool findings as that When we break up plumage-...
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Definition of “genomic adaptation”

I have encountered the term genomic adaptation in some literature (for example Sikkink et al. 2017). I am struggling to parse the term, and I have not been able to ...
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Clarification regarding a statement in “The Selfish Gene” by Richard Dawkins

In the third chapter of The Selfish Gene: Immortal coils, Dr.Dawkins makes the following statement while arguing for the case that ultimately "the gene" as he defines it is the unit of natural ...
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(Soft) Lay Survey of human natural history

I am looking for an introduction to the natural history of humans. I had originally thought Sapiens until I found out it is more a history and archeology book of dubious scientific accuracy. The Sorts ...
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Why do vertebrates have an oesophagus?

As far as I know, the oesophagus in vertebrates has no digestive or absorptive function. It is simply a conduit from the mouth to more distal parts of the gastrointestinal tract. Why have it at all, ...
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How verified experimentally is the Marginal Value Theorem for viruses?

Reading some Stanford notes on R0, they get to MVT and optimal virulence: Consider a directly-transmitted infection from which there is no recovery (e.g., Herpes Simplex). The population ...
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When did bison exchange smartness for larger skeletal muscles or a digestive system that can ferment grass?

Patricia Churchland (2019) writes: From time to time, evolution favors a dumbing down; sacrifice some smartness in exchange for larger skeletal muscles, like bison, or for a digestive system that ...
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Which is more evolved Rays or Sharks

I know the Theory of evolution explains that life transforms to become more complicated, sophisticated so that it's more equiped for survival, Just like the survival of the fittest, the fittest are ...
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An online tree of life with extinct species present?

There are awesome online phylogenetic trees such as OneZoom. But they all only list living species. I want to see dinosaurs between birds and crocodiles. I wanna see that humans are reptiliomorphs ...

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