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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Linkage disequilibrium, genetic drift and fitness variance

The very first two sentences of the abstract of this article is: "In finite populations subject to selection, genetic drift generates negative linkage disequilibrium, on average, even if selection ...
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1answer
70 views

Rate of Evolution of population of long lived individuals

Is it necessary that rate of evolution of longer lived trees will be lesser than that of annuals ? I understand that new individuals will come up faster in annuals and it may adapt to varying ...
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2answers
209 views

Are humans an eusocial species?

In the evolution of sociality among animals, different degrees are acknowledged. Some species present overlapping generations, some division of labor, and the minority present reproductive division. ...
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107 views

How many loci explain 50%, 80%, 99%, … of the total genetic variance in fitness?

Standard models in population genetics look up at the evolution of few loci which impact fitness. The variance in fitness is determined by the genetic variance and the environmental variance (and the ...
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2answers
1k views

How many times did life emerge from the ocean?

Evolution is often mistakenly depicted as linear in popular culture. One main feature of this depiction in popular culture, but even in science popularisation, is that some ocean-dwelling animal sheds ...
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2answers
116 views

Can diploidy evolve in absence of sexual reproduction?

Theoretical question Can diploidy (or polyploidy) evolve from a haploid lineage in the absence of sexual reproduction ? For what theoretical reason? How can such evolution take place? Empirical ...
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5answers
459 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?
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2answers
92 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 ...
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69 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 ...
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2k views

Height and natural selection in humans?

I watched the documentary "Evolve" recently and in the segment on "size" Scott V. Edwards, Harvard evolutionary biologist mentioned the idea that humans might evolve to be 7' tall in 'hundreds of ...
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Why do hummingbirds build nests with live ferns instead of dead materials?

Hummingbirds prefer to build their nests with spore-bearing ferns, and mosses. This is helpful for the reproduction of the ferns, which are then better able to spread their seeds. But how is this ...
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2answers
151 views

Can you answer Ray Comfort's question on Biological Evolution? [closed]

https://www.youtube.com/watch?v=U0u3-2CGOMQ There's this video on Youtube about biological Evolution that has gone viral. I'll paste it above for your convenience. To cut to the chase, Ray Comfort ...
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1answer
64 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? ...
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1answer
52 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 ...
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2answers
581 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?
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2answers
136 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 ...
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121 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 ...
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2answers
64 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 ...
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1answer
672 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 ...
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1answer
39 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. ...
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2answers
181 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 ...
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1answer
577 views

Difference in length of Okazaki fragments

The length of Okazaki fragments in the lagging strand is about 100-200 nucleotides in eukaryotes and about 1000-2000 nucleotides in prokaryotes. What (molecular mechanism, enzyme type ) ...
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0answers
24 views

What percentage of possible proteins has been tested by human brain evolution?

When the human human brain is discussed, I frequently hear an argument that goes like this "If there was a simple chemical solution for people to be smarter, nature would've already found it". I'm ...
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2answers
137 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 ...
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3answers
122 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 ...
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2answers
147 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? ...
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0answers
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Is it possible for bacteria to acquire family-wide antibiotic resistance?

If there is bacteria, lets say Enterococci that is sensitive to: Amoxycillin-Clavulinic acid Ampicillin-Sulbactam Ofloxacin Ciprofloxacin Is it possible to ...
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1answer
183 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 ...
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1answer
83 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 ...
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1answer
155 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 ...
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1answer
169 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 ...
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4answers
245 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? ...
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1answer
151 views

The Origin of Mitochondria

For a long time I've just accepted, because it is just what everyone told me, that mitochondria became organelles in the cell when they were "engulfed" by another cell which acted like it's host. This ...
3
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4answers
538 views

Refutation of Darwin's Random Evolution Theory

I saw this refutation online of Darwin's Random Evolution Theory and cannot see any holes with the logic. Can anyone crack this simple refutation? Refutation of the Theory of Random Evolution ...
21
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4answers
534 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 ...
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1answer
41 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 ...
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2answers
92 views

Evolutionary history: did any organs start out as autonomous organisms?

I've read that the cell nucleus was once an autonomous organism that was "enslaved" by the larger cell at the time of the Eukaryotic Revolution. Are there any organs in the human body that we know of ...
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3answers
198 views

Why did abiogenesis only happen once?

If the "primordial soup" theory of abiogenesis is to be believed, self-reproducing organisms spontaneously arose on Earth at least 3.5 billion years ago, surprisingly soon after the Earth cooled down ...
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2answers
107 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
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1answer
257 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 ...
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1answer
136 views

Birds from the Family Columbidae Feed Young “Crop Milk”

Birds from the family Columbidae (e.g., doves and pigeons) produce a fatty, milk-like substance in their crop. The secretion is often referred to as "crop milk." They feed crop milk to their young ...
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2answers
106 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 ...
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1answer
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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
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1answer
86 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 ...
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4answers
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Why do plants have green leaves and not red?

I know plants are green due to chlorophyll. Surely it would be more beneficial for plants to be red than green as by being green they reflect green light and do not absorb it even though green light ...
4
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1answer
65 views

DIfference between diversification and differentiation

In Adaptive dynamic : what is the difference between Ecological Differentiation and Ecological Divergence ?
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1answer
71 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: ...
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2answers
251 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
87 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 ...
2
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4answers
164 views

How come most animals never seem to evolve over millenia?

People often say, including those with extensive knowledge in biology, that a certain species of animal will evolve in one way or another: 1.From changing environments. 2.Mutations. 3.Possibly even ...