Evolution refers to the observed changes in successive generations of biological organisms due to heritable components (genes and DNA). Charles Darwin proposed a major mechanism of evolution: natural selection.
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Why do some animals have 8 Limbs (e.g. Spiders, Octopuses)?
Octopuses have 8 tentacles, spiders have 8 legs.
Is there something special about 8? It seems like an animal that needs 360° mobility has 8 legs.
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How might gene clusters like the lac operon evolve?
The obvious answer for a gene cluster is gene duplication and mutation of one or both genes. But the genes in the lac operon seem not be so functionally/structurally similar (as compared to the Hox ...
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What is the evolutionary rationale for palm sweating?
Sweaty palms seems to be a reaction to stress, anxiety, etc. For our forest-inhabiting primate ancestors sweaty palms could cause unwanted side-effects such as slipping off tree branches under ...
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Is there a timeline for the frequency of evolution of any species?
Evolution is traditionally spoken of as an inherited change over generations.
Does evolution happen one change at a time - or are there multiple changes occurring between two successive generations? ...
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Is there an evolutionary reason for the 5 electron transport complexes in plants and animals?
The electron transport chains of both the light reactions of photosynthesis (in plants) and oxidative phosphorylation (in animals) both contain 5 complexes including ATP synthase, as shown below.
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Have proteins been observed to come into existence through mutations and natural selection?
What is an example of a functional protein that has been observed (in real time) to have come into existence through mutations and natural selection (not through an existing one being made defective). ...
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Why Didn't Evolution Cause the Human Body to become Streamlined?
If streamlining makes movement/locomotion quicker and easier, why didn't the apes evolve into life-forms that had streamlined bodies (much like fish)?
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What are some examples of scaling laws in biology?
I've seen that metabolic rate scales logarithmically as function of mass for many animals over an extremely large span of parameters. What other scaling laws exist at the individual level?
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Why do sloths come down from the trees to defecate?
I'm under the impression that most sloths exhibit this behavior, but why? They are slow moving and so have no way of escaping from predators when on the ground. Not to mention the energy they expire ...
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What are samples of “Outlaw Genes”
I read this in a paper
Keller and Ross describe their greenbeard gene as an ‘outlaw’.
Admittedly, the comment is only made in passing, but are they correct?
In this context an outlaw is ...
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Is a “Fact” any theory for which there is overwhelming evidence in any field other than biology?
Evolution is often described as a fact, and a theory. Evolution is a heavily overloaded term, with one definition being the fact that, "changes in the frequency of alleles in populations of organisms ...
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Why people like to see pornographic scenes, but do not feel the same about eating scenes?
This question may seem funny, but I think biology must have good answers.
I think no more explanation is needed.
I really thought about this and searched for an answer, but there is nothing yet.
If ...
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Would ovoviparous to viviparous mutation have been gradual? How would that work?
It seems unlikely that an ovoviparous ancestor of mammals long ago could have had a viviparous offspring in a sharp one-generation dividing line, but what would be the gradual steps between egg birth ...
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Chromosome 2 fusion?
I read this article by Jeffrey Tomkins and Jerry Bergman claiming to debunk chromosome 2 fusion. Is there anything wrong with these conclusions?
" 1.The reputed fusion site is located in a ...
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Nucleotide frequencies in Kimura's two-parameter model
Here's an excerpt about Kimura's two-parameter model from Felsenstein's Inferring Phylogenies:
"The model is symmetrical, and one can immediately see that, after
enough time has elapsed, it ...
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Can parents' learned traits be transmitted genetically?
I am wondering whether a behavioral trait (e.g. fear or stress experienced in the lifetime of the parent) can be transmitted genetically to its offspring?
I understand that a behavioral tendency for ...
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Short-term Lamarckism in asexual single cell organisms
I was reading through the Karr et al. (2012) whole-cell computational model. One of the things they did was to induce single-gene disruptions in their model. They observed several to be fatal, but:
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Features in individuals causing high population variation
As I understand it, a population with high variation is something sought after, since it makes the population better equipped to face a dynamic environment.
Then, I guess features in an individual ...
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Are there natural selection experiments that quantitatively agree with theoretical modeling?
Has anyone ever conducted an evolution experiment and quantitatively compared it to theory? For example, has anyone ever put bacteria in a million petri dishes filled with antibiotics and calculated ...
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When does weak selection produce qualitatively different results from strong selection?
In evolutionary game theory, it is typical to model organisms as having a base fitness that is modified slightly by the game interaction. The ratio of the game effect versus the base fitness ...
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Why don't flies avoid the motorway?
Flies have a short lifespan, therefore evolution should technically happen over a shorter period of time (years).
Flies die all the time from getting hit by cars on the motorway.
Those flies that ...
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107 views
Fossils of intermediate stages?
If Humans are evolve from Monkeys, there must be stages in the evolution process, when it was 1% human and 99% monkey, 2% human and 98% monkey and so on. This is because evolution was a very slow ...
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Is there any complex organism that is both autotroph and heterotroph?
Possibility also include "adaptation mode" if such exist. I don't discern whether autotrophic/heterotrophic part play only minor role either.
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Is better healthcare a bane to the long-term survival of the human race?
The theory of natural selection has it that individuals with better genes tend to survive and reproduce, passing their genes to their offspring. This gradual process results in a population more ...
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Why is a slow worm not considered a snake?
Slow worms are considered lizards as opposed to snakes, both are reptiles. Now I get that there are traits that distinguish them (eye lids, ears ...). But snake species themselves vary already quite a ...
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Evolution after the development of sexual reproduction
My understanding of evolution is that genetic mutation occurs in individual members of a species, and they become a new species.
Isn't a definition of species a group of genetically similar organisms ...
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Macroevolution vs. microevolution
Where is the line usually drawn between macroevolution and microevolution?
I thought that, although similar processes govern both, the line was at the species level, with macroevolution being changes ...
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How did giraffes develop their rete mirabile failsafe?
Giraffes, being one of the tallest mammals in the world, have a failsafe called rete mirabile to prevent them from dying from excessive blood pressure while lowering their head.[1]
Due to their long ...
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Were there lifeforms before LUCA?
This question got me thinking about something. LUCA is the last universal common ancestor of all current living organisms, which is a very different definition from the first-ever living organism. Is ...
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Indestructible Super Shrimp
How are shrimp and other animals able to not be crushed by the 1000x greater pressure at the bottom on the Mariana trench?
Wiki says the trench is home to "large living creatures such as a sole or ...
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Is vision a vestigial sense for deep ocean species?
Sunlight doesn't penetrate beyond a couple of hundred feet from the surface of the ocean. Species that exist at greater depth probably live in a state of perpetual night; yet from a quick google image ...
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The oldest common ancesstor of all human beings
Do all human beings have a single oldest ancestor (a man and a woman), or were there were many ancestors at the same time at different places on earth?
This article sheds some light. Is there another ...
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Preserved alpha complementation over evolutionary time?
Has the result of alpha-complementation ever happened via mutation through evolutionary time, and been preserved in modern day organisms?
In other words, has a functional gene product ever been split ...
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Would non-human carnivores be able to survive on farmed foods?
Certain creatures that are considered carnivores are non-obligate carnivores and are technically omnivores (such as wolves/dogs). How different is the potential digestive ability of these species ...
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Is there an “Adam and Eve” for each new trait during (not just human) evolution? [duplicate]
Do new beneficial mutation evolve simultaneously and independently with several individuals of the same specie or only with one specimen who then transfers it to all of the specie?
In other words, ...
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How can I compare rates of evolution for two sets of proteins?
I have a list of candidate proteins as the result of my analysis. I am now trying to find various characteristics that they have in common. One of the things I would like to check is if my candidates ...
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Can epigenetic changes affect reproductive success?
This is prompted by niallhaslam's answer to this question [Since Darwinian times, has there been any striking/notable effects of evolution on humans?]. A comment by Alan Boyd asks whether epigenetic ...
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Biology view on trait variability
In reading the annotated Origin... I have come to the following note by Costa on p. 168:
Again, modern biologists would disagree with Darwin's idea that especially well-developed traits vary to a ...
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Why do humans bury their dead?
As far as we know Ape Men or the Neanderthal Man was the first to bury its dead. My question is why.
I don't think they practiced religion or believed in spirits or faith or stuff like that. ...
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Are humans still competing in the same way now that the first life forms did?
I'm not sure if this is actually a philosophical question, but I was reading a timeline of life on earth and I came to this:
4500-3500 Ma The earliest life appears, possibly at Alkaline vents
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Historical recovery from mass extinction events
Is there a way to generally characterize how species "regrew" after the various mass extinction events happening periodically from 450 Ma to 65 Ma. Would the surviving species just start back where ...
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How did the activities of protocells become inheritable?
I have learned that first a protocell came to exist and its characteristics came to be passed on by genetic material. So how come genes for all the activities come to incorporate into genetic ...
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What are some alternatives to Charles Darwin evolution except creationism? [closed]
What are alternatives to Charles Darwin evolution except creationism?
Is there any "hypothesis" except evolution and creationism or there is none?
Btw. I consider things like some proto-building ...
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How did this spider evolve to mimic exactly a human face and arms?
So I came across something terribly amazing today, that is, a video showing this species of peacock-spider, that literally, transforms into a human face waving his arms about.
What could have ...
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Evolutionally speaking, why do humans have 46 chromosomes
In humans, each cell normally contains 23 pairs of chromosomes, for a total of 46. Monkeys, chimpanzees, and Apes have 24 pairs (twenty-four pairs), for a total of 48.
What caused humans to have 46?
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Reproductive isolation causing evolution
My course book says about reproductive isolation that it does not allow the interbreeding among the individuals of different species. It also says that it is a cause of evolution.
How is this cause ...
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How can homosexuality evolve despite natural selection?
I would imagine that the answer to this question would be population control, especially since even if one sibling is homosexual this does not necessarily mean that the other siblings will be too.
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Evolutionary speaking, what is the purpose of girls masturbating?
In males they expel sperm in semen, but females orgasm with clitoral stimulation, and the clitoris has absolutely no evolutionary, sexually reproductive, or otherwise purpose outside of sexual ...
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Has medical progress stopped human evolution?
We can cure many diseases nowadays, and thus the natural selection is very limited.
Plus, mankind spent the whole beginning of its existence in almost the same hostile environment, and that's where he ...
