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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Why haven't prey evolved the ability to always outrun their predators?

I can understand why some prey can't outrun a recently evolved species. However, since cheetahs have existed for so long, why haven't its prey evolved to always outrun it, driving cheetahs to ...
4
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1answer
46 views

What animals have a blood-brain barrier?

I am curious about how old the BBB is, in terms of evolution. Is it present in all vertebrates? or just mammals? or what?
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1answer
75 views

How to read cladograms/phylograms?

I understand the difference between cladograms and phylograms; the latter can show the evolutionary linkage over time. However, I am having trouble finding out which two organisms are most closely ...
4
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2answers
361 views

How do traits with no negative effects get “weeded out” via evolution?

If only those who are most fit to reproduce are the ones reproducing the most, it makes sense that traits that prevent one from reproducing would eventually disappear from a population. But what ...
0
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0answers
64 views

Why do horses recycle their endometrial lining while humans don't?

How does not recycling the endometrial lining of the uterus benefit humans (and other organisms that menstruate), while recycling it is beneficial to horses (and other organisms that undergo estrus ...
7
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2answers
376 views

How did zootoxins evolve?

I've always wondered how toxins in certain organisms have evolved. Particularly, organisms that produce toxins as a deterrent to predators as opposed to organisms that use it to paralyze their prey. ...
24
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3answers
67k views

What is the difference between orthologs, paralogs and homologs?

These three terms are often misused in the literature. Many researchers seem to treat them as synonyms. So, what is the definition of each of these terms and how do they differ from one another?
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0answers
29 views

What empirical evidence of genetic assimilation is there?

There have been many articles arguing that we should view the phenotype in the center of evolutionary theory rather than the genotype as done in most population (or quantitative) genetics. A typical ...
4
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3answers
5k views

What if rB=C in hamilton's rule?

Hamilton's rule states that if rB>C then a gene giving altruistic behaviour will increase in frequency in the population. What would happen if rB=C? Will an individual perform the altruistic act?
4
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0answers
81 views

Do animals have different taste preferences within the same species?

Humans (especially children...) seem to dislike certain foods or drinks, that other humans seem to like. Common examples are coffee, french cheeses, olives, milk, fish and cabbage. Are there examples ...
-2
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1answer
45 views

Would someone lose some of their traits if they stop using them for some time? [closed]

A co-worker of mine told me, that there are some mutations in the genome during the life of a human body. So, the body changes genes to fit better into the surrounding environment. My thought is now, ...
3
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2answers
81 views

Why does the gc content deviate from 50% in prokaryotes

I have read quite some articles but I can't figure out the main reason for gc content deviation in prokaryotes. In eukaryotes I can understand it, because the genome isn't composed at random, like ...
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0answers
17 views

Are there any individual animals that can thrive in a wide range of core temperatures? [closed]

Surely, some cold blooded animals are in a position where they can't escape the changing temperatures the environment throws at them, so natural selection would have enabled them to thrive in a wide ...
4
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1answer
138 views

What were the camels' humps good for back in the polar areas?

I've heard that camels lived in the North America formerly and just in the last few thousands years they've migrated to the hot deserts. Thus they allegedly utilized the adaptations against the cold ...
44
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5answers
5k views

Why do some bad traits evolve, and good ones don't?

If a trait would be advantageous to an organism then why hasn't it evolved yet? Conversely, if a trait is not advantageous or mildly disadvantageous, why does it exist? In other words why does ...
2
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3answers
83 views

How valid is the theory of human's chimp-pig origin? [closed]

Edit: I have also asked the question on skeptics.stackexchange.com and it has been answered there. Here is the link. There is a person called Dr. Eugene McCarthy who has a theory that the origin of ...
3
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0answers
27 views

What is the effective population size of a simple two deme metapopulation?

I am confused as to how to compute the effective population size $N_e$ of a theoretical structured population. Let's consider here a simple case study. Imagine a 2-deme metapopulation. Each deme is ...
5
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2answers
8k views

What factors are known to affect evolution?

My understanding is that the possible mechanisms of evolution are: Environmental changes Cultural/mating preferences Population Immigration Genetic Mutation Am I missing anything? I've heard that ...
0
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0answers
43 views

Is there an evolutionary advantage associated with migraine? [duplicate]

I have read Wikipedia article on Genetics of migraine headaches and I don't buy it Because genetics influence susceptibility to migraine, it can be shaped by evolution. Fitness-impairing ...
2
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1answer
51 views

Why does the wavelength in curly hair differ?

Different people and animals have different wavelengths in the curls in their hair. I understand what purposes hair serves in protecting the skin from light and bugs. I am wondering about the eventual ...
16
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3answers
2k views

Why are turtles classified as reptiles and not amphibians?

I understand that turtles are reptiles because like all reptiles, they have scales on their body. But turtles (specifically sea turtles) live on both land and water, very much like amphibians. Also, ...
1
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0answers
32 views

Why don't animals need filtered water? [duplicate]

Almost 10 years back when I was a kid, we had a picture in our school text of wild buffaloes drinking water from a river - which was visibly muddy. I asked my mother of why we need to drink filtered ...
3
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2answers
124 views

Hamilton's Rule in practice

I came across this question in USABO 2013 open exam: A mother antelope and its child are galloping along the plains, when they encounter a group of hungry lions. If the two antelopes try to escape ...
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1answer
96 views

Why do fruits have to ripen?

It seems like most fruits that we consume undergo some sort of ripening process either before or after they are picked from the vine, tree, etc. I understand that sugars are released during the ...
0
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2answers
68 views

Are heterozygotes always fitter than homozygotes? Can inbreeding be beneficial?

Inbreeding is mostly not very good because when there is a 'disease' in one allele, the other could/would take over the function. But when you have two of the same genes/alleles, do they, or could ...
4
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2answers
88 views

What's the correct name for the war of sexes in evolution?

I'm searching for the correct term for the part of the selfish gene evolution regarding sexes. In nature, this means the evolution of the traits such as the ducks' adaptation to "trap" the drakes' ...
5
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2answers
199 views

Empirical evidence for Group Selection?

A controversial concept in Biology "Group Selection", has caused confusion and conflict amongst scientists since the since the mid 1990s. The more general realm of study is termed the "unit of ...
0
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1answer
113 views

Why does the Vas Deferens detour over the pubic bone?

I was surprised to learn that the vas deferens detours over the pubic bone instead of taking the obviously more direct path. https://human.biodigital.com/widget?be=u1P&uaid=1ly5V Because I would ...
4
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2answers
634 views

Why is the strength of genetic drift inversely proportional to the population size?

I saw a concept on the Internet that says "the strength of genetic drift is inversely proportional to the population size". I don't know why they are inversely proportional? Can somebody explain? ...
6
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3answers
153 views

Why are the human knees and elbows bent in an opposite direction

I can assume that the hands used to be the same as legs. And they got weaken, and changed direction when human started to walk on two? Also why do the hand palms facing the body and not facing down ...
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1answer
59 views

What is the difference between natural selection and adaptation?

From what I've read it seems that the only actual difference is that creationists use adaptation and people who believe in evolution use natural selection. But otherwise, from my understanding, the ...
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0answers
19 views

Ecological specialization and relative abundance

I am reading Evolution in Changing Environments by R. Levin but have a hard time. Claim At page 25, Levin says as a conclusion The more efficient a caste at meeting the contingency for which it ...
2
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0answers
138 views

Have people in Africa already started evolving resistance to AIDS?

Are people living in areas where AIDS is rampant (for e.g. Africa), less likely to die from it than they once were because some of the people without genes/mutations that give them resistance already ...
18
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1answer
5k views

Why can't humans drink sea water?

Why can't humans drink sea water? It would seem to be a huge evolutionary advantage for an animal to be able to drink sea water rather than have to rely on fresh water, and it's provably not ...
0
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1answer
24 views

Without plant breeding and domestication, would most of the foods consumed by humans evolve to become inedible?

Would this happen? Do species evolve to avoid being consumed, especially the animal species which have no need to leave seeds?
2
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1answer
45 views

If crocodiles are k-selected, why do they supposedly “not age,” as in avoid senescence?

I recently saw a few sources stating that Crocodiles do not biologically age, implying negligible senescence. Basically, a 70 year old crocodile is in the same physical/health condition as a 7 year ...
9
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2answers
757 views

Why does sexual selection evolve beautiful features?

I have a very raw understanding of sexual selection: Say a group of females of a certain species "likes" some feature of a certain groups of males; by "like" I mean some behaviour that makes this ...
1
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1answer
97 views

Is evolution a predictive theory? [closed]

My feeling is that almost any observation can be explained by current evolutionary theory. Is there any example of someone developing a rigorous framework or mathematical model of how evolution works?
1
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1answer
36 views

How does mutualism arise? [closed]

How can a mutualism between two species arise? I have thinking about this for a while and I have come up with the following points 1.If mutualism gives one specie a competitive edge over its ...
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2answers
211 views

How quantitative is the theory of evolution right now? [closed]

We developed complex structures like eyes and brain, whose mechanisms rely on specific species of molecules and relevant chemical reactions. But we did not develop an enhanced night vision, the ...
8
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2answers
408 views

Why do squirrels have twitchy bushy tails?

Whenever I see a squirrel in the woods, it is always the big bushy tail flipping around that gets my attention first. A pray animal with a big bushy flag calling attention to it's self seems to be ...
11
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1answer
1k views

Darwin's first sketch of a phylogenetic tree

Coming from Darwin's notebook this first sketch of a phylogenetic tree became one of the most emblematic image from Darwin's work. I have a hard time to read what is written on it. What is written ...
13
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3answers
5k views

What is the evolutionary reason behind the fragility of teeth?

Almost all organs in the human body have a rather large threshold within which the organ or tissue is capable of repairing itself using materials supplied by the body, whether it's made from organic ...
0
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1answer
35 views

A doubt on Introgression

Wikipedia says that Introgression, also known as introgressive hybridization, in genetics is the movement of a gene (gene flow) from one species into the gene pool of another by the repeated ...
0
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1answer
18 views

Statistical genetics: Allele frequencies that follow a Dirichlet distribution

From Foll and Gagiotti (2008) (software BayeScan). They consider a model where several subpopulation are derived from a unique ancestral population. We consider a set of $I$ loci and let $K_i$ be ...
18
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2answers
3k views

How can birds disperse seeds when they are able to digest them?

I've just read in a book that birds' guts can digest almost all the consumed seeds with the exception of mistletoe and loranthus (which stays stuck on the branches). On the other hand, I know that the ...
8
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2answers
5k views

Why is it beneficial for trees to grow that tall?

Why is it beneficial for trees to grow that tall? This sounds like a kid's question Mom, Dad... why are trees so tall? Costs and Benefits There are some obvious ...
3
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1answer
58 views

Is there selection against long proteins and long genes?

Background thought Titin and TTN Titin is the largest protein in the human genome with 33423 amino acids. Titin is coded by the gene TTN that must be at least $3 \cdot 33423 \approx 100kb$ long. ...
8
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1answer
165 views

Up to date, extensive documentary about dinosaurs?

I just finished reading the Wikipedia page about dinosaurs, and I very much enjoyed it. I knew that much of what I learned in the 80's as a child is (and was) incorrect, and now that I am a parent, I ...
0
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2answers
53 views

Simple computational biology project for AP Biology class. Ideas? [closed]

Our teacher assigned us a project to do with an extremely open-ended prompt and it should be completed within a month. I was planning on doing something related to computation and evolution in terms ...