Questions tagged [evolution]

Changes in the heritable attributes of populations of organisms over time. The mechanisms of evolution are mutation, migration, drift, and selection.

Filter by
Sorted by
Tagged with
1
vote
1answer
32 views

Will the sex ratio of chickens become favourable to females?

As male chickens are killed after birth in mass farming. Will being male become a negative evolutionary trait, that is to say will females become more likely as male death is more likely.
-2
votes
0answers
36 views

Is our data about DNA purely empirical?

I was curious about what makes some things living. The concept of a virus prompted me to think about that. I read that a virus is a very simple organism with only DNA in it. This DNA is the "...
0
votes
0answers
32 views

What does it mean for there to be no correlation between phylogenetic independent contrast?

I am testing the correlation between two physiological parameters in plants using the pic function in R. I am a bit stuck on the interpretation of the phylogenetic independent contrast (PIC). Without ...
-3
votes
0answers
51 views

Why are humans so different to apes? [closed]

If we think of all the things that make us uniquely human: hairless walk upright language use of tools and weapons sweating cooking meat war swimming dancing singing It's seems like any one of these ...
0
votes
1answer
28 views

Is the frequency at which a species mutate affected by natural selection? [duplicate]

As per natural selection, is it safe to assume that some species will have it genetically encoded so that they produce a certain 'perfect' rate of mutation so that they can adapt to an environment ...
0
votes
4answers
120 views

Why doesn't evolution converge on perfection? [duplicate]

I got to know about an organism called "Tardigrade(water bear)" which is an extremely hardy organism and can survive in most conditions. My question is that if the aim of life in general is to ...
0
votes
1answer
115 views

Does natural selection still increase biological complexity?

I recently read The Selfish Gene by Richard Dawkins, which I found very interesting. In one of the last chapters, he gives multiple possible explanations to the question "Why did natural selection ...
4
votes
2answers
49 views

What might earlier versions of caddisfly shelter-building behavior have looked like?

The caddisfly has an amazing ability to build armor for itself by using a self-produced underwater glue to hold together pebbles: https://www.youtube.com/watch?v=Z3BHrzDHoYo. How could this behavior ...
0
votes
0answers
27 views

What is the oval shaped bone in the heads of some fishes?

I had a dish of fish and found 2 oval shaped nearly 1cm long bones in its head.What help does it do to the fish? what is its name? I have clicked the picture myself .
2
votes
1answer
117 views

How many generations are required for a specific neutral mutation to reach fixation?

In population genetics, the term “time to fixation” is defined as the time it takes for a specific mutation to appear in a population, plus the time required for this mutation to spread throughout ...
-4
votes
0answers
58 views

How could viruses evolve?

I know that Viruses are really complex generally, but what makes me wonder is, how they evolved. As an example, I first use a giraffe. The neck got really long so she could reach the leafes on the ...
0
votes
1answer
60 views

What are the disadvantages of myelin

The myelination of axons has plenty of advantages. It increases signal speed in axons, and thereby reduces reaction times. This is, of course, very good for the survival of the animal in question. ...
2
votes
0answers
72 views

Evolution of the unique mating system of the scorpion Androctonus australis

Sperm transfer in the scorpion Androctonus australis involves a sclerotized spermatophore, which is formed in the paraxial organs of the male reproductive system. The right paraxial organ produces the ...
2
votes
2answers
53 views

How did interspecies reciprocity involving cleaner wrasses originate?

The small bluestreak cleaner wrasse (Labroides dimidiatus) will approach a much larger fish (for example a grouper such as Cephalopholis miniata), enter its mouth, and spends several minutes cleaning ...
0
votes
1answer
64 views

Is there any program or website that allows me to create phylogenetic trees without having to insert an already created dataset?

I asked a similar question on Quora before, but did not get any useful answers as the program the one answerer suggested turned out to have the exact same problems as all others I have found so far. ...
0
votes
0answers
49 views

In asexually reproduced species, is HGT the only thing that enables existence of species there?

If some single celled organism which reproduces asexually, and without horizontal gene transfer, I guess after some number of generations, ALL descendants of some individual will be different enough ...
1
vote
0answers
104 views

Genetic variance for a behavioural trait among human populations

From this article from The Guardian: We instinctively assume that differences in behaviour that are in fact due to culture must be linked to – even caused by – characteristics of appearance. That ...
1
vote
2answers
69 views

What evolutionary advantages does a longer muzzle have against a shorter muzzle and vice versa

Basically I'm curious as to why when it comes to mammalian predators that some like say bears and canines tend to have longer muzzles than those like big cats. aside from their ancestors/evolutionary ...
-3
votes
1answer
48 views

What's the evolutionary benefit of stress and cortisol? [closed]

Stress and cortisol lower immunity and increase hard disease. But why is it that way? If that's true then we shouldn't be stressful at all. What's the benefit of stress then? Why do we (and most ...
-5
votes
2answers
63 views

Evolution of recurrent laryngeal nerve in a giraffe [closed]

Do natural selection and survival of the fittest explain the divergent length of the recurrent laryngeal nerve...centimeters in the human, 15 feet in the giraffe?
1
vote
1answer
24 views

Is Urea excretion a shared ancestral trait of amphibians and mammals relative to synapomorphic Uric Acid excretion in living reptiles?

Is the ancestral condition of prehistoric amphibians and early amniotes urea excretion? Would it follow then that the lineage leading to living reptiles went on to evolve uric acid excretion as a ...
1
vote
1answer
28 views

lifespan of Nautilus compared to other cephalopods

Most cephalopods live uncharacteristically short lifes compared to other creatures of their size and intelligence. The octopuses with the longest lifespan for example, the giant pacific octopus, only ...
-1
votes
3answers
46 views

Can convergent evolution be used to explain similarity of genome of low and high Species e g. gorilla and human?

Example: 1) molecule Rhodopsin in halobacteria for producing energy from light. 2) molecule Rhodopsin for vision in human. These are said to be of different lineages and their high similarity are due ...
0
votes
2answers
64 views

Evolution of hunting behavior of parasitoid wasps

Wasps in the genus Pepsis lay their eggs in a specific region on a species of tarantula and their larvae eat the tarantula organs in a specific sequence to keep it alive as long as possible. How ...
1
vote
1answer
63 views

What are the implications/predictions of the selfish gene theory?

Are there any testable predictions or implications of the selfish gene theory? Or it is just interesting interpretation of the observations/experimental data? If this theory is not falsifiable and ...
0
votes
1answer
15 views

What is indirect vs direction selection of genes?

As the title suggests, what is the direct and indirect selection of genes. Couldn't find a straightforward answer. Is it the same as direct and indirect fitness?
1
vote
1answer
70 views

A theory about the possible connection between protists and first animalia

I learnt that organisms within Kingdom Animalia can be either microanimals or (nonmicro)animals. a microanimal is any Kingdom Animalia organism that in general cannot be seen by a human eye without ...
0
votes
2answers
104 views

Is evolution always unidirectional?

Is it possible, at least in theory, for a species to evolve into another species and then evolve back into the first species?
0
votes
0answers
28 views

A question about the clarity of certain terms

In the Red Queen's depiction, a population must evolve just to be able to survive its ever-evolving natural enemies. I'm trying to refer to a state in which many natural enemies have evolved adaptive ...
0
votes
0answers
70 views

Examples of animals who 'forget' their offspring

Occasionally on the news I read about young children dying in hot cars on a sunny day. Usually the article reports that the parent(s) 'forgot' about their children still being in the car. Obviously ...
0
votes
0answers
14 views

Evolution of multicellular eggs

Which animals where the first in which ova were not simply released, but instead provided with some additional nutrition and/or protection in the form of a larger egg?
1
vote
0answers
21 views

Who were the first authors to talk about local adaptation?

I was curious to read about what Darwin had to say about the existance of locally adapted subpopulations. I discovered to my surprise that the expressions and terms "local adaptation", "spatial ...
1
vote
0answers
33 views

Thermophilic plants which are also halophilic?

I know that in botany there is a wide classification for plants that can survive in hot deserts (semi-arid or arid) and harsh climates such as 4-season countries with a tendency to droughts each year (...
0
votes
1answer
27 views

Modern understanding Darwin's “correlation of variation”

In Variation under Domestication, Darwin makes several references to the concept of "correlation of variation": I will here only allude to what may be called correlated variation. Important changes ...
0
votes
0answers
15 views

Causes of different patterns of speciation within lineages

Over the course of evolution, some lineages divide repeatedly into sublineages of comparable size (I suppose this is what's meant by a radiation), while others form a grade leading to a single large ...
0
votes
0answers
46 views

life based on different elements [duplicate]

It is commonly proposed to look for life based on silicon, based on it's relative abundance and similarity to carbon. However, carbon and silicon are not completely interchangeable. The bond strength ...
1
vote
2answers
68 views

ELI5 what is true breeding?

In "Variation under Domestication", Darwin makes several references to the concept of true breeding: They believe that every race which breeds true, let the distinctive characters be ever so slight,...
0
votes
1answer
57 views

Have there been multiple aboriginal species of dogs?

In "Variation under Domestication", Darwin writes that: I may here state, that, looking to the domestic dogs of the whole world, I have, after a laborious collection of all known facts, come to the ...
0
votes
1answer
63 views

From DNA data, is it easier to conclude that chimpanzees are our close relative, than it is to do a paternity testing?

Well, today I was contemplating on how to explain evolution, approaching with the dialectic method. When it came to why chimpanzees and us being so close in the tree of evolution isn't outright absurd,...
-3
votes
1answer
62 views

How did the woodpecker's tongue evolve? Is not is simply impossible? [closed]

How the tongue got wrapped that way? What were the intermediate stages?
0
votes
0answers
19 views

Book recommendations on the evolution of trees

Trees have been around for hundreds of millions of years, since the first "true wood" evolved during the Devonian period ~400M years ago. This means we have fossilized wood in the form of tree ferns, ...
0
votes
0answers
56 views

DNA of Different Species and The Fossil Record of Their Common Ancestor

Let me please be clear about something. I believe in evolution. The evidence and data are compelling and conclusive which makes it a very well-established theory. I'm seeking a certain evidence (if ...
-4
votes
1answer
84 views

Has human intelligence evolved as a costly male signal?

In this video at 42:06, Daniel Dennett posits that our big brains are: The human artifice or version of the peacock's tail. Peacocks have sexual dimorphism - it's males who exhibit the costly ...
1
vote
2answers
118 views

What advantage does lactose have as the main sugar in milk?

Most organisms have lactose as their main sugar in their milk. What advantage does lactose give have over sucrose (Which is a common sugar in the plants, so it makes sense for it to be present in ...
7
votes
1answer
63 views

Why does music give you emotions?

Why do we feel emotions when we hear music? Click to see video How can a set of tones arranged in a specific order and timing make you feel sad or happy? I read that music can somehow trigger the ...
1
vote
1answer
83 views

Why did Darwin say “the misfortune to undertake”?

Why did Darwin say "the misfortune to undertake"? "Every naturalist who has had the misfortune to undertake the description of a group of highly varying organisms, has encountered cases (I speak ...
7
votes
2answers
89 views

How does a drastic change to the genome persist and spread?

I just read the article on songbirds in the November, 2019 Scientific American. The article explains that songbirds have an extra chromosome, called GRC (germ-line restricted chromosome) that other ...
0
votes
0answers
27 views

Brain evolution in the age of the caesarian

I have just been reading an account of the evolution of human intelligence in Matthew Syed’s recent book on diversity, called “Rebel Minds”. He is not the originator of this idea, but he suggests ...
1
vote
3answers
187 views

Is evolution a means to an end?

In "The Red Queen", Matt Ridley frequently argues that evolution is a means to an end, without providing much explanation for such a big statement. Is this a fact in biology? Do species mutate their ...
27
votes
3answers
6k views

Does animal blood, esp. human, really have similar salinity as ocean water, and does that prove anything about evolution?

It is an often-repeated claim that human, and in fact all animal blood is salty because we evolved from aquatic organisms, and that blood has a similar concentration of salts as ocean water, or at ...