Changes in the heritable attributes of populations of organisms over time. Major mechanisms include drift, natural selection, mutation, and gene flow (migration).

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How come there are animals (like lizards) that can regrow their tail, but no animals can regrow a penis? [on hold]

It seems like the penis is the more important appendage for evolutionary purposes, doesn't it? In which case, why are there no animals that can regrow a penis (or is there?)? I understand that often ...
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3answers
66 views

What's the mechanism or structure responsible for new species genetic code generation?

I always had this question in mind. I think, If humans find answer to it then we can trigger the next evolution of human specie. What is the mechanism or structure responsible for evolution ? I don't ...
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1answer
32 views

Why plants and animals are so different even though they come from the same ancestors?

All the documentaries I have watched, books I have read so far on the starting of life on earth only talk about animals. The very first life form on earth was bacteria. Then evolution took us this ...
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2answers
56 views

Are human beings evolved to eat meat? [duplicate]

I know humans can cook, and prepare almost anything, but are humans specifically adapted to eat meat. One of my doubts humans are not particularly well adapted to eat meat because they lack canine ...
3
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0answers
31 views

Escaping resource limitations during tumor evolution

In their discussion of the importance of r- and K-selection on tumors, Aktipis et al. (2013; figure 3) provide the following illustration of a hypothetical cancer growth curve: In it, you can see ...
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0answers
3 views

How to incorporate intraspecific variation in discrete characters in comparative analyzes?

I'd like to run a multivariate analysis (Pavoine et al. 2011) that aims to disentagle the effect of environmental gradients on traits, considering its autocorrelation with phylogeny and space. It uses ...
3
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2answers
47 views

Crossing over and exon shuffling?

Campbell Biology 10e, in discussing the functions of introns, writes: The presence of introns in a gene may facilitate the evolution of new and potentially beneficial proteins as a result of a ...
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0answers
109 views

Why did multicellular organisms evolve when a single cell can survive on its own? [duplicate]

Since unicellular organisms can survive, why would there be evolution of multicellular organisms?
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1answer
40 views

Why did eukaryotic cells develop? [closed]

If eukaryotic cells can survive in extreme conditions, then why are their still prokaryotic organisms?
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21 views

Does the bending of a tree's trunk in the wind stimulate and strengthen root growth?

Recently Southern California experienced extreme wind velocities and afterwards the news reported over 300 trees had fallen in San Diego County. I had either heard or read somewhere that the action of ...
3
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1answer
50 views

What came first? The DNA or the DNA polymerases?

I know this sounds a lot like chicken and egg question and while the latter has an answer, I am intrigued about the former. A modified form of the question would be, in the course of abiogenesis, ...
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1answer
73 views

Why do simplier plants live in water? [closed]

Lower plants such like algae are considered to be simplier organisms, than those plants that live in water. Why had'nt they evolved as much as the land kind?
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1answer
38 views

Is it known how human sweat glands evolved?

If human descends from apes than probably we lost our hair. Perhaps in the age of homo erectus we lost our hairs and began transpiring through our skin with sweat glands. But how did these glands ...
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1answer
72 views

Evidence of species transitions [closed]

I had a debate with a person who believes in some kind of creativism, let's call it that way. And in the middle of the "debate", an interesting question popped up. What are evidences of ...
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1answer
37 views

Was the frequency of mutations more during primitive earth due to radioactivity?

Primitive earth was more radioactive (or was it really?) according to radiometric analysis of C14 which suddenly appeared at 4250 million years in the Hadeon eon. Is it possible that ancient high ...
2
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0answers
26 views

The evolution of sleep [duplicate]

Are there evolutionary theories as to why we (and most animals) sleep? Some claimed functions of sleep include: restoration, waste clearance, memory processing, etc. But unless we understand why ...
3
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0answers
43 views

Why doesn't lard taste good? [closed]

I mean looking from evolutionary perspective sugar tastes sweet and individuals that had this perception ate more sugar and survived and those that didn't perceive sugar as sweet didn't eat it and ...
3
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1answer
92 views

Why does Citric Acid occur in Citrus fruits?

Why is there so much citric acid in citrus fruits? And how did it evolve i.e. what did it come from? Is it a by-product of the ripening process? Why have citrus fruit evolved a particularly high ...
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1answer
141 views

Examples of animals with 12-28 legs?

Many commonly known animals' limbs usually number between 0 and 10. For example, a non-exhaustive list: snakes have 0 Members of Bipedidae have 2 legs. Birds and humans have 2 legs (but 4 limbs) ...
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42 views

Do animals demonstrate target practice (i.e., playful accuracy behavior)?

Do animals demonstrate any sort of accuracy-motivated play? (please provide examples!) Consider most human sports and related hobbies. Most share the common goal of hitting a target or being ...
0
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1answer
103 views

Have scientists ever produce a new species in laboratory by means of natural selection?

I was wondering, if scientists ever produce a more complex species from a less complex species by means of natural selection? I imagine something like, bacteria which can't photosynthesis and oxygen ...
2
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1answer
46 views

How to understand Aposematism and Batesian mimicry

EDIT I want to understand the reason for intense animal colors. I.e. I don't want to understand the variety of the colors, just the intensity. The Wikipedia page for Cethosia biblis says, the intense ...
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1answer
60 views

Does evolution thinks? [closed]

I understand evolution as survival of the fittest rule , where its the nature and surroundings that shapes the life by extinction of species which are not fit to survive the nature at that period. To ...
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2answers
78 views

Are there any predators without camouflage?

Are there any predators that don't use camouflage?
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1answer
59 views

Is there a formal definition of signature of natural selection?

I’ve searched for a definition of signature of natural selection. Unfortunately, I haven’t found any formal definition of it. The signature of positive selection ...
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3answers
266 views

Symmetry of species [duplicate]

I've got a silly question, sorry for that. I know, that we probably have no the right answer and the current answer could be "that's evolution, external conditions". I'd like to speculate, why most of ...
7
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1answer
63 views

Why does the proportion of transposable elements vary so much across species?

Intuitively, transposable elements (TEs) are harmful as they may cause genome instability. However, some people argue that TEs are also sources of variations, especially regulatory sequences[1]. If ...
0
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1answer
49 views

What makes animal to continually reproduce? [closed]

I was reading about Trypophobia and reached to Surinam Toad's reproduction methods. Then I had this doubt- Why would animals want to reproduce so much? In case of humans we mostly have the offsprings ...
2
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1answer
61 views

What are some useful (starter) metrics to use on phylogenetic trees?

Im doing a computational biology project in which I simulate evolution under different inheritance rulesets and I am generating phylogenetic trees (beautifully visualised in python with ete3, which I ...
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18 views

Why is marginal reconstruction “more correct” than joint reconstruction in some cases?

When reconstructing the ancestral states on a phylogenetic tree given the states at the tips, there are a number of methods for performing the reconstruction. This question is about marginal and joint ...
0
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0answers
14 views

Are Betaproteobacteria more 'simple' than Gammaproteobacteria?

More generally, are all proteobacteria named in order of complexity (Alpha, Beta, Gamma, Delta, Epsilon)? If so, would it be right to say that Betaproteobacteria can survive in lower nutrition / more ...
5
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3answers
441 views

3-minute long inspiring videos on evolutionary biology

What I am looking for I would like to start my teaching sessions with short emotional, awe-inspiring or exciting videos that are somehow related to evolutionary biology (incl. diversity of life, ...
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1answer
159 views

What are the minimum conditions required for “open-ended evolution”?

According to a paper about artificial life systems, the following four conditions have to be fulfilled for "open-ended evolution": Condition 1: A rule should be enforced that individuals must ...
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1answer
199 views

Bootstrapping (symmetry breaking) in evolution [closed]

Many fascinating phenomena in nature show different behaviours on the micro and the macro level. Here I am especially referring to phenomena that are symmetric on the micro and asymmetric on the macro ...
3
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4answers
112 views

Is an egg classified based on the species inside it, or by the species that laid it?

Basically what I'm asking is if an animal of species x were to lay an egg, and the animal inside that egg happened to be the first member of a genetically new ...
27
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5answers
7k views

If evolution is not about improvement, why is there so much improvement?

In my last question I asked why we don't see improvement in artificial life simulations of evolution. It seems I had fallen for a common misconception, that evolution was about improvement. One ...
5
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2answers
1k views

What are we missing about the real workings of the evolutionary process? [closed]

As a scientist (and a computer scientist at that) my view is that if we cannot simulate a process we have not understood it properly. I have been following the interesting field of Artificial Life for ...
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1answer
66 views

Regression to the mean and evolution

I don't have a strong biological background but, in studying statistics, I met the idea of regression to the mean. e.g. children of tall parents tend to be shorter than their parents, and so on. Does ...
0
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1answer
68 views

When was the last common ancestor of pig and human?

Some religions regard pigs as unclean on the grounds that pig flesh is closest in composition to human flesh. I don't believe this for one instant, but it got me thinking, just how close is pig and ...
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1answer
53 views

Why do most organisms depend on water? [closed]

Most organisms depend on water for metabolisms. Even the higher organisms need to maintain their daily water intake. Why water and not something else (for example like H2S)? I know H2S is poisonous ...
3
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2answers
175 views

Do mutant alleles result from mutation of the wild type?

The allele that encodes for the most common form of a phenotype in natural population is called a wild type allele and all the rest of the alleles encoding forms other than the wild type are called ...
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1answer
30 views

Difference/similarity between adaptive radiation and species divergence?

I've been reading various answers on different sites but I still don't know whether adaptive radiation and species divergence are different or similar. My questions: 1) On some sites, it says that ...
5
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0answers
36 views

Is high metabolism linked to high evolutionary turnover?

I recently read The Dinosaur Heresies by Robert T. Bakker, a 1986 popular science book presenting arguments for an active lifestyle and high metabolic rate in dinosaurs. One of the arguments that ...
0
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2answers
188 views

Why even if all requirements for natural selection are met, it may not happen?

In the book written by John Endler Natural Selection in the Wild p. 4 it says that even if condition a, b and c are met, evolution by natural selection might occur, [...] , but not necessarily, ...
3
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0answers
28 views

Effect of sex-ratio on the effective population size

As stated on this wikipedia article, the effective population size $N_e$ when the sex ratio differs from $\frac{1}{2}$ is $$N_e = \frac{4N_mN_f}{N_m+N_f}$$ I understand the biased sex-ratio ...
5
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1answer
146 views

What is the origin of prions?

We know something about the origin of the first cell. But what do we know about prions? How did they originate?
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2answers
95 views

Why human skin colour disprove natural selection? [duplicate]

Amount of melanin decides the darkness and fairness of skin. The darker the skin is, larger the heat energy it will absorb from sunlight. The lighter the skin is, less will be the heat energy ...
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0answers
34 views

Diffusion approximation to genetic drift

Textbook I am reading from the classical textbook Principles of Population Genetics, Hartl and Clark (pdf here). Introduction $f(p,x,t)$ is the distribution of allele frequency $x$ at time $t$ ...
3
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2answers
69 views

Why was Darwin's Finch argument valid considering Weismann's argument?

According to Darwin, there was only 1 species of Finch bird in Galapagos. Then Darwin argued that due to diet adaptation and natural selection, their beak changes causing new species--which is ...
8
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3answers
205 views

Why have parasites not evolved to be harmless?

I have yet to understand why so many viruses or bacteria haven't evolved to be harmless (specifically, I don't know of any harmless virus). I think it would be greatly beneficial for a virus to ...