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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5answers
597 views

What is meant in biology by the term “evolved”?

A student asked me this the other day and I thought that I would ask it again here. If one organism is said to be "more evolved" than another, what exactly does this mean?
4
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2answers
382 views

Why aren't we ambidextrous?

It seems so simple that if my brain can tell my right hand to do something, then it should be able to tell equally well to the left ? This seems like a pretty major evolutionary advantage. Why haven't ...
1
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1answer
229 views

Birds and Dinosaurs

This came up in an argument with some friends. I know that birds are direct descendants of dinosaurs, shown pretty clearly through the fossil record. However, is it proper to say that birds are ...
-1
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1answer
80 views

Can nature create codes and specified complexity? [closed]

Is there an example of nature creating codes or specified complexity? It is said by Creationists that codes can only come from minds, and since DNA has a code, it was created by a mind. Is this true? ...
3
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1answer
74 views

What's the use of RNA editing in kinetoplast?

The genes of the mitochondrion (kinetoplast) of some Kinetoplastida - e.g. Trypanosoma brucei, the parasite which causes African sleeping sickness - are "encoded" in a way that the pre mRNA requiries ...
8
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2answers
2k views

why is AUG the initiation codon?

Is there any reason why AUG is the initiation codon ? Why is there a need for an initiation codon ? Can't translation start with different codons?
4
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2answers
183 views

Why and how does complexity usually tends to increase through time?

The question of complexity is classic in the very first lectures of evolutionary biology where the teacher usually tries to tell the students that complexity does not necessary increases and that ...
7
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2answers
162 views

The Assumption of Weak Selection?

I was reading this question and I failed to fully understand the introductory part of it. The OP (@Artem Kaznatcheev) says: Most analytic models like to assume weak selection because it allows ...
-1
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2answers
83 views

Could a normative population ever be non-heterosexual? [closed]

In the modern documentary called "Bi the way", one American geneticist said that if modern American youngsters may as well be functionally bisexual, then some generations ahead Americans could be ...
1
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1answer
1k views

What are the differences between G+ and G- bacteria?

The distinction between Gram-positive and Gram-negative bacteria is based upon the Gram staining method, that reflects the bacterial wall physical properties. However, this classification involves ...
2
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1answer
52 views

Evolutionary conservativeness

List the following proteins in the order of decreasing evolutionary conservativeness of their primary structure: Somatotropin. Catalytic subunit of a DNA – polymerase. Histone H1. ...
5
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2answers
3k views

Why do we assume that the first humans were dark-skinned?

According to the article Dark skin and blue eyes: How Europeans once looked: It is widely accepted that Man's oldest common forefather was dark skinned, and that people became more pale as they ...
-1
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2answers
407 views

How did fish evolve the ability to breathe on land?

Doesn't make sense. It would be like a human evolving the ability to breathe on the moon without a spacesuit. How would the organism be able to carry out such an evolutionary adaptation, when the ...
7
votes
3answers
183 views

How should I put a large phylogeny into a scientific paper?

I've been trying to put a phylogeny tree into a scientific paper. This tree includes ~220 species, which is too too large for one page for journal articles (Letter or A4 size). But in my paper it is ...
1
vote
1answer
928 views

Evolution- Variations, adaptations and selective advantages

I am trying to understand Variations, adaptations and selective advantages and how they are all related. Feel free to add or correct me if I'm wrong- Variations are structural, functional, or ...
1
vote
1answer
113 views

Can we say that microevolution and macroevolution is fundamentally the same thing over different time scales?

This Wikipedia article states: Macroevolution is evolution on a scale of separated gene pools. Macroevolutionary studies focus on change that occurs at or above the level of species, in contrast ...
4
votes
1answer
288 views

Why do farts stink, but perfume does not?

Why is it that natural things like farts, poop, halitosis etc., from which we are always surrounded smell "bad"; whereas manufactured products, such as perfume or glue smell "good" to most of us? In ...
3
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1answer
243 views

Macroevolution vs. microevolution

Where is the line usually drawn between macroevolution and microevolution? I thought that, although similar processes govern both, the line was at the species level, with macroevolution being changes ...
2
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4answers
292 views

Are we inevitable in the evolution?

Suppose we wind time back to the instance when life emerged on Earth and let evolution start over again, will human beings or any other kind of self-conscious animals evolve ultimately, inevitably? ...
21
votes
4answers
781 views

How many times did endosymbiosis occur?

According to the endosymbiont theory, mitochondria and chloroplasts originated as bacteria which were engulfed by larger cells. How many times is it estimated that this occurred in the past? Are there ...
1
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1answer
155 views

Definition of “Regime of selection”

How would you define Regime of selection (or Selection regime)? In addition to a accurate definition, a developped example ...
2
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2answers
182 views

Book recommendations for algorithms used in evolutionary biology

Do you have recommendations for a book that presents the different algorithm used in theoretical evolutionary biology? I don't mean evolutionary or genetic algorithms (otherwise this question would ...
3
votes
1answer
486 views

Ka/Ks (dN/dS) analysis module for Python?

From this wiki article: In genetics, the Ka/Ks ratio (or ω, dN/dS), is the ratio of the number of Nonsynonymous substitutions per non-synonymous site (Ka) to the number of synonymous ...
5
votes
2answers
123 views

Is there theory that connects longevity, time-scale of environmental disturbance, and adaptation?

I'm thinking here about environmental disturbance or like climate change-driven warming. It seems as if there are two macroevolutionary ways to deal with environmental change: 1) Have short ...
-7
votes
1answer
199 views

I believe in variation of a species but not in evolution [closed]

I can see that variation within species exists, for example birds with various size beaks adapted for specific food-gathering purposes, one may have a larger beak vs. smaller beak, OK that works for ...
4
votes
1answer
134 views

Does conjugation support gene selection?

I have already posted this on chat but haven't got any response. A recent question on group selection stimulated me to ask this here. QUESTIONS: Why should bacteria conjugate? If we consider that a ...
4
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1answer
232 views

DIfference between diversification and differentiation

In Adaptive dynamic : what is the difference between Ecological Differentiation and Ecological Divergence ?
0
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1answer
97 views

Current human behavior as a genetic heritage

People: I have doubts about genetic heritage, but let me explain the context which has shown up this doubt for you: I was debating about sexism and the following question were put on the discussion: ...
11
votes
2answers
373 views

What are the evolutionary niches differentiating an apple from a pear?

So, as far as I understand (basic) evolutionary theories, diversity is generated by "niching." That is, if there is an environmental factor that hasn't been fully used by any species to "profit" off, ...
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2answers
126 views

How likely is it that Earth has millions of different species?

I know that the probability of life existing on a habitable planet is pretty slim. But, how likely is it that it hapenned millions of times in the same planet? Or was it only a few species that ...
0
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2answers
171 views

Is there any genetic similarity that defy evolution theory?

For example, say species A is common ancestor of B, and C. Species B is a common ancestor of D and E. We would expect that there will be more genetic similarity between D and E than D and C. And ...
2
votes
1answer
238 views

What are the visual, behavioral similarities and differences between Yellow Fever Mosquito (Aedes aegypti) and the Tiger Mosquito (Aedes albopictus)?

The Tiger and Yellow Fever Mosquito visually look very similar. Recognizing the difference is important for tracking and controlling the spread of Yellow Fever, Dengue fever and other diseases. ...
2
votes
2answers
593 views

Are there genetic similarity between humans and pigs that don't exist in chimps?

Chimps are our closer relative. Any genetic similarity between humans and chimps must exist on the common ancestor. Pig branch out sooner. So, any genetic similarity between humans and pigs must be ...
5
votes
1answer
48 views

Is there any evidence telling us what the oxidation state of early earth's atmosphere was?

I ask this question in relation to the origin of life. I realise it would probably be better suited to a geology stack exchange, but it does not yet exist. The Miller-Urey experiment gives a lab ...
0
votes
1answer
114 views

Does avocado and orange have a common ancestor?

While I'm eating my orange, I felt as if I was eating avocado. It might be genetic manipulations perhaps but it made me think if they have a common evolutionary ancestor. Is there?
3
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2answers
1k views

The number of nipples (breasts) a species has?

Only mammals have mammaries and mammary glands. What evolutionary factors determines the number of mammaries (nipples/teats/breasts) a species has? Is it always an even number?
3
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1answer
78 views

Chemoautotrophy in large organisms?

The major nutritional mechanisms include chemoautotrophy, heterotrophy (including parasitism and saprotrophy) and photoautotrophy. All of these modes of nutrition developed first in prokaryotic ...
1
vote
1answer
1k views

Cats, Dogs and Bears - how are they related?

What is the ancestral relationship between cats, dogs and bears? I presume they are more closely related to one another than other paraphyletic clades of mammal. Which came first? What did their ...
1
vote
2answers
174 views

Effect of zero selection (pressure) on the population health

Evolution naturally produces better features: stronger muscles, teeth and minds. Killing the weakest, evolution wipes defective genes out of populations. The mutations are necessary for advance. ...
4
votes
1answer
114 views

Natural enemies boost deep evolutionary fitness?

"Two species that reduce one another's fitness on microevolutionary (short-term) timescales can increase each other's macroevolutionary (long-term) fitness" Opinions? Intuitive Examples: ...
3
votes
1answer
52 views

Are there cannibalistic k-selectors?

My understanding of r- and k-selectors does not go deeper than the wikipedia article. I understand k-selectors to be creatures that put tendentially more effort and energy into rearing their ...
8
votes
1answer
141 views

Is there a comprehensive database of fossils (with images) online?

Not sure if this is the best stackexchange to ask... I have not been able to find a decent database of fossils on the web, does one exist? Here are some of the links I have found through Wikipedia ...
4
votes
1answer
64 views

How much can you learn about species variation from a skeleton?

I just read about the discovery of the 1.8-million-year-old human skull in Georgia, and how it suggests that early humans were all one species instead of distinct ones. Would an archaeologist ...
1
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1answer
214 views

What is the most recent non-primate ancestors of humans?

If we go down the evolutionary tree of humans, (Homo sapiens, Homo erectus, ...), what will be the first non-primate ancestors?
1
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3answers
1k views

Does Darwin's Theory of Evolution refute Terence McKenna theory “Stoned Ape” theory of human evolution?

I haven't read it but I'm asking for a quick answer. As far as I know, Terence McKenna's theory of evolution in humans main concept is that a hominid has tried in their diet psilocybin mushrooms, and ...
2
votes
1answer
62 views

Does the existence of one species imply the existence of many other?

Reading one of Sir Arthur Clarke's scifi stories, I came across a statement something to the effect of, existence of a single species automatically implies the existence of many other species. So ...
0
votes
2answers
781 views

Why have humans evolved conciousness?

Why did humans/animals evolve to become self-aware of their own thoughts. That is, why don't humans act and compute like a machine, or walking zombie. In my mind, such creatures would still be as ...
3
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2answers
269 views

Why is there such an argument about evolution?

DISCLAIMER: I am a Christian, although I happen to believe that some form of guided evolution via natural selection is God's mechanism for creation. Now to my question, which is related to my ...
4
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1answer
187 views

What is the evolutionary advantage of regret?

Some motivational speakers may say that regrets are only useful to learn something from. What are the other advantages?
9
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3answers
5k views

Why does human facial and head hair continue to grow?

Many people can grow extremely long head hair and facial hair. Are there evolutionary theories as to why this is the case? It seems like having long hair could be a disadvantage, and extremely long ...