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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3 views
Tensile strength of articular cartilage
The tensile strength of human hyaline cartilage is 5 mpa. The human tibia has an area of 3.25cm2. A 100kg human would put 3mpa of force on this area. The force would multiply when taking a step.
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0answers
10 views
Why, evolutionarily, does the genus Latrodectus have such potent venom?
As far as I know, the venom of most species of spider in the family Theridiidae is not dangerous to humans. However, the genus Latrodectus is well known for having venom medically significant to ...
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1answer
35 views
Reversal form of endosymbiotic theory?
Cell's organelles give us evidence that they might have been independent organisms on their own.
Are there any single-cell microorganisms known to have gone so to say this way back as well, i.e. ...
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3answers
58 views
Does evolution produce organisms perfectly adapted to their environment? [on hold]
I have this biology assignment with this chosen topic. I have no idea where to start researching. I have studied the mechanisms and theories of evolution. I just don't know which relates to the topic. ...
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0answers
25 views
What advantage does a bird have from defecating in its drinking water?
We have a water table for birds. Only one bird uses it, a pigeon. This bird drinks from the water, then turns around and defecates into the water, then flies off. It returns later and does the same ...
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1answer
29 views
Is transition more common than transversion during the evolution of duplicated genes?
Transitions are base mutations of purine to purine (A <-> G) or pyrimidine to pyrimidine (C <-> T). Transversions are purine to pyrimidine or vice versa (A <-> C, A <-> T, G <-> C, G &...
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0answers
15 views
Possible to breed human-adverse mosquitoes?
Some time ago I read a paper on fruit flies, in which the researchers bred a population of flies to avoid a particular fruit. They did this by exposing the flies to two different types of food (say, ...
2
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0answers
20 views
Learning tensors for evolutionary or developmental biology
I'm looking for book recommendations on tensor algebra for use in biology.
Tensors are being used increasingly in evolutionary biology and developmental biology, it seems. For example, here is an ...
4
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1answer
352 views
What kind of owl does this moth look like?
I found this moth and I noticed that it looked like an owl to me and remembered something about how some moths camouflages look like predictors? What kind of moth this is and what owl does this moth ...
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0answers
43 views
Limitations of the human brain [closed]
Why did humans evolved to put limitations on our brain power? Was intrigued by savant cases that gave a peek into the full potential of our human brain. Sadly we cannot unlock its full potential
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1answer
36 views
Examples of points in evolution where two species stopped being interfertile? [on hold]
Apologies in advance for not using the right terminology here; I'm not a biologist. This isn't for homework or anything; just curiosity.
I'm wondering: at what point do two divergent species stop ...
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0answers
15 views
How did craniates evolve?
Looking at most chordate phylogenetic trees, it seems that we usually have something like this:
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1answer
78 views
Population genetics indicates that a billion years are needed for establishment of the millions of genetic differences between human and chimpanzee
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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1answer
38 views
Pangenesis and Lamarck's theory of inheritance of acquired characteristics
I've read that Darwin had split ways with Lamarck's evolutionary ideas. Yet his theory of pangenesis seems to support Lamarck's theory of inheritance of acquired characteristics. What am I missing?
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1answer
76 views
Are we evolving as fast as the oxygen is depleting?
How much oxygen saturation have we lost in the last 100 years? As oxygen levels dwindle and industry, deforestation, and population increases, at what year and saturation will the low levels of ...
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1answer
68 views
If wolves (or foxes) are fitter than rabbits, why rabbits have not become extinct? [duplicate]
I do not pretend to "demolish" the Darwinian theory of biological evolution and the "survival of the fittest", that's far from my intention.
I have this doubt because of the fact that humanity, as ...
2
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1answer
30 views
What is the adaptive significance of temperature dependent sex determination?
Why do some reptiles have TDSD ? Is it because one of the genders is healthier than the other that only they, can survive high temperatures?
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0answers
40 views
Why do we have a protruding nose?
What is the evolutionary reason behind a protruding nose ?
And why don't monkeys and chimpanzees, for example, have it? Some say that the large brain in the skull kicks out the nose. But why do we ...
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1answer
38 views
Time taken for species to become endemic
Is it known how long species take to become endemic? I know from examples such as Canada which have no endemics following the end of glaciation that the process must take at least 10 thousand years, ...
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0answers
14 views
Can a polyploid be a “clone” of a single parent?
I still need to learn more about the different mechanisms for polyploidy, but from what I can tell, a polyploid can be an exact clone of the parent, except that its chromosome count has doubled. If ...
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1answer
58 views
About The Selfish Gene Book - How Replicators Molecules forms duplicates?
I was reading The Selfish Gene. In the 2nd chapter - "Replicators" I read:
Think of the replicator as a mold or template. Imagine it as a large molecule consisting of a complex chain of various ...
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3answers
51 views
Why aren't all infections immune-system resistant?
It's been less than a century since the widespread use of antibotics started, and already we're seeing bacteria that have evolved immunities to the antibotics we use.
On the other hand, we've been ...
4
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2answers
54 views
Visual and clear example of the idea that “animal doesn't need to understand the evolutionary function of its actions”
This is a question about education. I am trying to come up with a very visual and clear example, to explain a particular concept in evolution.
The concept I am trying to explain is,
the fact that ...
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1answer
34 views
Why and how does falsifying sensory information work? [closed]
Some context, before the question:
Whenever I have a craving to binge on something sugary, I just prepare a cup of extremely bitter green tea (with 3 bags of tea) and I imagine myself binging on ...
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1answer
29 views
Neuroscience - A neuron with two types of synapses (electrical and chemical) at the same time
I learn that the nerves from the Peripheral Nervous System can carry signals from and to other organs of the body.
I'm wondering if A Single Nerve carries
1) Only chemical signals
2) Only physical ...
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1answer
63 views
Paper saying that humans and animals are (mostly) the same age
I'm brazilian and today I've came across this news published in a religious brazilian site. It's about a recent study that says that 9 to 10 species on Earth today, including humans, came into being ...
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0answers
17 views
Did the chromosomal fusion within humans affect phenotypical change compared to the separated chromosomes in the other apes?
I just read this article on the evolutionary divergence between humans and chimps, and how the most significant event was when the 24 number of chromosomes in chimps was reduced to 23 in humans due to ...
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1answer
95 views
Dependency graph of life
This is a fascinating paper I read using Bayesian analysis to compare different graph models to genomic data. Intriguingly, it shows that a dependency graph is a much better fit than a tree model. ...
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1answer
34 views
Black oyster of sweet water
I have seen recently a documentary starting with introducing of the spectacular black oyster of sweet waters which imitate exactly like a prey fish in order to convey its eggs to predator fish's gills,...
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1answer
61 views
Are there limits to drug resistance?
It's well-known that indiscriminate use of a drug leads to resistance. My question is what the limits on resistance are. It seems obvious that there must be limits: for example I can hardly imagine a ...
2
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1answer
76 views
What to call a trait that has current utility but unclear evolutionary origin?
I'm looking for a commonly used term to describe a trait that has clear current utility but an evolutionary origin that is uncertain and that we do not necessarily wish to emphasize in our description ...
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1answer
31 views
Factors That Would Promote Eusocial Development In Mammals?
What would cause mammals to evolve to be more eusocial, like the naked mole rat did? What advantages does eusociality give in such scenarios?
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0answers
22 views
Hamilton's rule: When to change the equation?
So, in class, my teacher gave two examples of using hamilton's rule. Let b= 4 and c=2.5.
The first was whether altruism would evolve between two diploid full siblings given these values. Since r=1/2, ...
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2answers
44 views
what are some examples of how evolution's limitations prevented species from climbing to the absolute highest peak on the fitness scale?
In this answer, the author argued that plants are green instead of red or any other color because of some limitations of the evolutionary process. what are other examples in which the physical and ...
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2answers
88 views
If life began at sea, why organisms are less salty than the sea?
We may take it for granted that a fish, a seaweed, or clams are not too salty to eat, although the sea around them is salty. I know about the existence of a mechanism which prevents their body from ...
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1answer
36 views
How would I represent this on a cladogram?
So, right now I am making a cladogram (More of a dendrogram) for a kingdom of fictional species, and I'm not exactly sure how to represent a certain relationship.
Let's say that the oldest class in ...
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0answers
19 views
Are there any open phylogenetic projects that don't require coding to make a contribution
I am stay at home learner, not pursuing education formal education and currently doing a part time job. I've however completed masters in biotechnology and I'm studying to pursue PhD in molecular ...
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0answers
32 views
How to quantify the strength of social bonding between the individuals of a colony? How to compare the strength of social bonding across the species?
Consider two different species of honey bees. If I have to compare the strength of social bonding between the two species i.e. in which species, social bonding between the individuals is stronger than ...
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2answers
38 views
What (if any) is the shortest evolutionary process observed by humans? [duplicate]
So when I think of evolutionary processes, I think of it taking millions of years to happen. Like how humans evolved from monkeys or birds evolved from dinosaurs (I know that is super-duper simplified)...
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1answer
68 views
Are all mammals capable of sneezing?
I only know dogs and humans sneeze... so do other mammals sneeze as well? Is it possibly an evolutionarily-determined immunological trigger?
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3answers
79 views
What did the evolution of multicellular animals look like?
What did the evolution of multicellular animals look like?
Aspects of this question include:
(1) Are there any living organisms that might be helpful in visualizing "transitional forms" between ...
2
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1answer
42 views
Why do most theories assume “only” sexual reproduction can cause genetic diversity?
The reason cited for sexual reproduction trumping over asexual reproduction broadly relies on the advantages of genetic diversity.
This completely overlooks the fact that a mutant which is able to ...
11
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6answers
223 views
Why are there not two trees of life?
Life on earth started an estimated 3.8 billion years ago, very soon (in geological time) after the earth’s surface cooled to become solid and the first oceans formed. Nowadays, we believe that all ...
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0answers
33 views
Why aren't “Water Giraffes” a thing?
If we assume that the Brachiosaurus and the modern Giraffe with their long necks both came to be by the need to reach higher-situated vegetable nutrition (which is a somewhat controversial assumption ...
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1answer
80 views
When is Semelparous reproduction most likely to be favoured?
Under which of the following conditions is Semelparous reproduction (where organisms produces all its offspring in a single reproductive event) is most likely to be favoured? (A) Adult survival rate ...
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2answers
41 views
Is it true that it is mostly impossible, for any kind of antibiotic, to succeed in killing off every bacteria in a very rich environment?
It is commonly believed that the resistance to antibiotics by micro-organisms is truly evolution at work, and that the recent surge in superbugs may very well be attributed to it.
When we refer to a ...
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0answers
22 views
What is the difference between disruptive selection and opposing directional selection?
I'm wondering if there is a difference conceptually between disruptive selection and 2 opposing directional selection. As you can read here, it seems that disruptive selection can be thought as ...
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1answer
18 views
How taking up plasmids on heat shock evolutionary advantageous to bacteria?
During the transformation protocol we apply heat shock to bacteria to make them take up plasmids from their environment. It is really useful in the lab.
However, it presents an evolutionary paradox ...
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0answers
24 views
Are seeds alive and by what mechanism do they 'Spring back to life'?
Correct me if I'm wrong but, human and plant cells require, at least to my understanding, a supply of energy, water and other neutrients to survive and carry out functions (such as sell division). ...
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2answers
39 views
MLE estimation with Mk model in ape or phangorn?
When doing MLE with the R package ape or phangorn, is it possible to set the substitution model to Mk? If so, how does one do this?
