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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Is Homo sapiens the only extant species of genus "Homo"?
Is Homo sapiens the only species of genus "Homo" that survived?
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Do some colors trigger more neural activity in human brain?
On this webpage I found this:
The study found that “globs” in the brains of monkeys reacted differently to colored
stimuli, and reacted based on color. The brain was most triggered by specific ...
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Why do humans not have a powerful sense of smell?
It seems like a useful ability to be able to detect many different things about, say, another organism. A lot of mammals have this ability. Why not humans? Did we evolve it out or never develop it?
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Did the hyoid bone of Australipetichus afarensis have a hyoid bulla?
The hyoid bulla is present in Chimpanzee hyoid bones, and not in Humans. Does A. afarensis have a hyoid bulla?
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When looking at skulls from early hominids, how do we know their language creation abilities?
If there are no vocal chords left, how do scientists deduce what sounds the specimen was able to create?
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Extreme or just rare: evolution of complex life in extreme environments [closed]
Many environments are considered "extreme" (boiling hot springs, acidic/basic water, etc) and those tend to be dominated by Archaea instead of the "usual" mixture of bacteria along with complex plants ...
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How extensive was interbreeding among human species?
I have read this article about non-Africans interbreeding with Neanderthals, Neanderthals interbreeding with Denisovans, and Asians interbreeding with Denisovans as well.
Now, I'm wondering what ...
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Is it mostly true that predators or parasites traverse wider spatial areas than their prey or hosts?
Does it tend to be true that as you go up the food chain, the species tend to cover wider areas? I am basically asking whether a population's prey varies spatially more than a population's predators ...
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Cat's tail movement as an indicative of tension
It appears to me that tail's twitching in the cats indicates how much tension the individual is under. During a hunt, when a cat tries to stay invisible, while approaching a target it is almost ...
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Phylogenetic Independent Contrasts with discrete traits
I understand that PICs are normally only used for continuous traits. However, on this how-to site (https://www.r-phylo.org/wiki/HowTo/Phylogenetic_Independent_Contrasts) there is mention of "Discrete ...
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How many genes are needed for a living organism? [duplicate]
I am interested in this question as I'm doing research into early life on earth which is believed to have been single-celled. Therefore, by extension, it seems only logical that the first life would ...
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Do the recent findings of an ape-like creature in Europe with human-like teeth change the Out of Africa narrative?
http://www.telegraph.co.uk/science/2017/05/22/europe-birthplace-mankind-not-africa-scientists-find/
Two fossils of an ape with human-like teeth were discovered in Greece, and Bulgaria, and they are ...
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Animals with substantial five-fold symmetry besides starfish? Any land animals?
Animals with four, six and eight legs are widespread while the concept of seven legs (fictitious Heptapods) are the makings of amazing scifi short stories and blockbuster movies.
Are starfish the ...
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Maximum parsimony tree - Am I right, or is the correction model right?
Alright. Monday we have a test, and now I was making a practise test.
We have to make a maximum parsimony tree. We must do that monday again, so I want to know if I am thinking wrong, or if the ...
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Has human evolution currently stopped? [duplicate]
Due to the advent of social networking and dating sites, it is now possible for almost anyone to find a potential mate. Therefore, there is not as much of a pressure based on physical characteristics ...
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How does evolution get around the combinatorial problem?
Imagine a combinatorial tree showing all the possible arrangements of nucleotides. Some arrangements are functional, meaning they can be plugged into a cell and create a living organism capable of ...
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What is the necessary criterion for the maintenance of signaling honesty?
Zahavi's (1975, Journal of Theoretical Biology) handicap principle held that the cost associated with a signal is integral to ensuring that signal is accurate, since dishonest signals would be too ...
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Text Book Recommendation: Organic Evolution
I was wondering if anyone could point me in the direction of any text books on organic evolution? I have recently become interested in the subject and would like to know more. I think an undergrad ...
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Why do sulfur compounds smell?
Many of the compounds of sulfur have a strong odor. Hydrogen sulfide from rotten eggs, the mercaptans of a skunk, the odor compounds in onions and garlic, the bitter taste of brassicas (cabbage, ...
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Why is the heart not in the middle of the body?
All mammals that I can think of have a high degree of bilateral symmetry (In fact, almost every animal I can think of is like this).
So why is the human heart not exactly in the middle of the body? ...
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Are bacteria incapable of producing cytokines such as interleukins?
As far as I understand, bacteria cannot produce cytokines such as interleukins. However, I have not read an explanation as to why they cannot. Perhaps it has to do with an evolutionary limitation. Yet,...
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What is the biology behind human population dynamics?
A paradox: Human population growth looks a lot like a simple logistic growth pattern. But the simplest interpretation of logistic growth doesn't seem to fit. Is this peculiar to humans, or does it ...
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Figuring out an honest indicator in intrasexual selection [closed]
In the first picture, the parameter $r$ seems to compare the direction and strength of two variables. In the second picture, $R^2$ seems to describe the variation of proportion of independent and ...
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How is "selection" best defined?
There is natural selection but there is also sexual selection which some regard as a category of natural selection. There is also artificial selection (by humans). The question is, what is a most ...
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Why do people feel shame when exposed nakedly?
Why do people feel shame? Meaning the kind of shame specifically related to exposing 'private parts'.
Where does it come from (i.e. social factors due to upbringing, inherent in our genes etc.)?
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Evolutionary term for multiple, related adaptations
Is there a term in biology for when adaptations are compounded on (or by) other adaptations?
One example in whales: the tail flukes, reduction of rear limbs and development of the blowhole were all ...
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What is the difference between phylogenetic tree "construction" and "reconstruction"?
When I look through papers, there are two terms
Phylogenetic tree construction
Phylogenetic tree "Re"construction
What is the difference between phylogenetic tree "construction" and "reconstruction" ...
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Analogous organs: coevolution or opportunism?
The question reads as: "The lens of many vertebrate eyes is a crystallized form of a protein that also functions in digestion as a metabolic enzyme. This shows that
A. Vision and digestion co-evolved
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What is the most basic organism to respond to Classical conditioning (capable of learning)? [duplicate]
I have been doing some reading of Classical conditioning which is considered to be an indication of animal's ability to learn...
Before this I considered insects to be machine like - devoid of any ...
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Is Race the Result of Microevolution
I've been studying evolution for some time and was wondering whether the emergence of different races is an example of micro evolution within our species?
Bonus Question: is it impossible for homo ...
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What is Hamilton's rule for multiple generations?
What is Hamilton's rule as it applies to multiple generations? Is it that the lineage success given up by the actor must be exceeded by the lineage success acquired times the relatedness between ...
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Why did many species of Homo and their ancestors evolve in East Africa?
One thing I find interesting about the theory of evolution is the idea that Homo Erectus and Habilis evolved in Africa, began to spread around the globe, then was superseded by Homo Sapiens Sapiens ...
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Do mosquitoes allow for DNA transfer between unrelated species?
A mosquito can bite individuals of different species and eventually allow for some blood of one species to enter into the bloodstream of another species which I suppose may eventually cause DNA ...
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Dinosaurs vs. humans [duplicate]
If dinosaurs were here so much longer than humans, why did their natural selection not account for higher intelligence, as is the case in humans?
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Why did viruses evolve in the first place?
This question might seem kind of strange, but it's something I've been chewing on for ages, and I can't really think of a good answer.
Viruses just seem to be floating around passively until they ...
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Why did black swans to evolve black colouring?
What environmental factor caused black swans, which are native in Western Australia, to evolve black feathers ? Note swans are either black or white, there are no brown or grey colurings, which can be ...
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How did Portuguese man-of-war evolve?
In particular, how did the close cooperation of its many component species evolve?
My hypothesis is that it began with a few, probably no more than two zooids cooperating in symbiosis, and overtime, ...
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Are mutations accumulating far faster than selected out?
I just want to see the mutation accumulation rate in human populations. Versus the rate at which mutations are selected out. Just wanted to check if the genome is deteriorating
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Is abiogenesis possible today?
Life on earth started about 3.5 billion years ago. I would assume abiogenesis happened because the conditions were right.
Would the current earth conditions allow for new abiogenesis and completely ...
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Did the capacity to be "knocked out" arise because it conferred an evolutionary advantage?
From first principles, it seems surprising that a blow to the head would cause unconsciousness rather than just impaired function.
I've heard a lot of analogies to computers -- "Your brain has to ...
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If I workout, will this inherited trait (of being stronger) not be passed down to my offspring (Lamarck's theory on evolution)?
I'm a student in biology and just recently learned about Lamarck's theory on evolution and how it has been disproved. While I understand that you cannot alter your genes, I'm still having a hard time ...
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Polymorphism in number of chromosomes?
The answer to this question, saying that Down Syndrome - a trisomy of human chromosome 21 - is caused by de novo mutation (rather than resulting from standing variation) made me think about ...
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Is there a theoretical maximum on the number of sexes a given species can have?
Background: To the best of my knowledge, most sexually-reproducing species of organism have two sexes, although there are also sexually-reproducing species of organism (flatworms come to mind) which ...
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Can the value of heritability be greater than 1?
Heritability defined as genetic variance divided by total variance seems to be bounded between 0 and 1. However, I see a way of calculating heritability on this page (http://www.radford.edu/~rsheehy/...
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Lengthening muscles not good from evolutional perspective? Why do we do it with explicit stretching?
Stretching has many advantages, among other things it helps us to be flexible in our movement (which is an advantage?!).
But why do we need to actively stretch, it seems that the body wants to ...
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In the NCBI Taxonomy tree what does "no rank" mean?
NCBI publish their taxonomy browser at https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi
While many taxa have a well defined rank (Order, Family, Genus etc..), some of them have "no rank".
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Are human disease-causing organisms living in other creatures helpful to them? [closed]
There are many examples of this.
How is rabies helpful to a dog?
How are Zika virus & Malaria helpful to a Mosquito?
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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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How could cyanobacteria survive the anaerobic conditions of ancient earth?
I was reading about cyanobacteria and came to know that they are the first organisms that filled the atmosphere with oxygen around 2.3 billion years ago but then I realized that they themselves are ...
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Nature of transmarginal inhibition
I've recently become aware about existence of such phenomena. From my naive point of view, I understood it as existence of two general types of neural cells, one type serve inhibitory purpose and the ...
