The theory by which mutations in the genetic code lead to differences from the previous phenotype that, should they be advantageous to an organism's survival to reproductive age, may be passed on to offspring.

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Why estimate linear and full (linear, quadratic, and correlational) selection coefficients separately?

"We then fitted a linear regression including all three life-history traits to estimate the vector of linear selection gradients, β, for each sex (Lande and Arnold 1983). A quadratic regression ...
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2answers
55 views

How can natural selection occur at species level whilst not occuring at the individual level?

The chapter by Douglas Futuyma in 'Evolution' (Losos et al 2013, Princeton) states that natural selection can occur at the species level. Futuyma states that if natural selection occurs at the species ...
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29 views

Is genetic drift necessarily deleterious?

I read that genetic drift is random variation in the relative allele frequencies of a population. This question however seems to pin genetic drift down to increasing deleterious allele ...
4
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1answer
41 views

Drake's Law. What is the genome-wide mutation rate and what are the estimates?

Drake's rule Drake's rule states that the genome-wide mutation rate is more or less constant across all species — from E.coli to the house sparrow. Data From what I think being Drake's original ...
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1answer
46 views

What is the progressive evolutionary advantage that leads to flying?

As far as I understand, all life started as non-flying and flying came about by natural selection. What is the evolutionary advantageous "path" to flying? Or is there something else to explain this?
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24 views

Niche differentiation in birds of prey

I'm not much of an ornithologist but I know enough to distinguish most Central European birds of prey. To me it is amazing that there are so many species that seem to occupy the same niche. Especially ...
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1answer
67 views

How prominent is the gene-centric view of evolution among professional researchers?

Richard Dawkins famously advocated a gene-centric (as opposed to organism-centric) viewpoint on natural selection, most notably in The Extended Phenotype. However, I have also heard "on the grapevine" ...
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365 views

What is the difference between eugenics and evolution by natural selection?

So with the working definition of Eugenics: "the aim to improve the human gene pool". What are key features that distinguish Eugenics from evolution by natural selection? I mean, besides that natural ...
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27 views

Gene duplication and subfunctionalization

I’ve been intrigued by gene duplication and want to learn more about it. I’ve read the following from here: several studies suggest that the proportion of duplicated genes retained in ...
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23 views

Are there multicellular isogamous species?

Are there multicellular isogamous species? Seeking through the examples of wikipedia I would tend to think that there are no multicellular isogamous species.
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37 views

Ancestral states of sex determination system

Most (maybe all?) species that reproduce sexually have either genders (anisogamy) or mating types (isogamy). There exist today many different type of sexual determination system. There is a whole ...
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20 views

What is most ancestral: isogamy or anisogamy?

Sexual reproduction can be feasible with anisogamy (gametes of different sizes i.e. genders) or isogamy (gametes of same size i.e. mating types) or with undifferentiated gametes (i.e. true random ...
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34 views

Why are there no animals with a length greater than 30-40 meters or with a mass greater than 200 tonnes? [duplicate]

The biggest and heaviest aquatic animal is the blue whale: 30 meters long and a mass of 200 tonnes. The biggest and heaviest terrestrial animal was a Sauropod (plant-eating, long-necked dinosaur): 40 ...
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1answer
99 views

Effects of selection on effective population size

Background The effective population size ($N_e$) is a central concept of evolutionary biology and is influenced by several parameters. For example: sex ratio bias affects $N_e$ $\left(N_e = ...
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65 views

Are humans the only living species that have the concept of exercise? [closed]

Humans have the concept of working out and exercising to keep themselves healthy. I have not heard of any other species that does the same, but I am just being ignorant. Are humans the only living ...
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1answer
45 views

Definitions of robustness and canalization

The concepts of robustness and canalization are fashionable today in the biology literature. However, I am not sure of their definitions and I am not sure either that all authors actually use the same ...
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45 views

Is there an association between environmental and mutational robustness?

The robustness of a genotype is the ability of this genotype to resist (always produce the same phenotype) to various parameters such as mutations and environment. The ability of a genotype to resist ...
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18 views

Mutation-drift equilibrium and among loci variance in heterozygosity

At mutation-drift balance, the increased heterozygosity brought by new mutations is exactly equal to the loss of heterozygosity due to genetic drift. At equilibrium, the expected heterozygosity for a ...
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1answer
185 views

Fisher's Geometric Model for Dummies

Fisher's geometric model is still today one of the most important and fundamental model in evolutionary biology but it seems to me that most student in evolutionary biology don't really understand it ...
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3answers
665 views

The evolutionary process in bird wings, especially with regard to winglets

In this answer on aviation.SE a comparison is made between the shapes of airplanes wings and the shapes of birds wings. It concludes with the following remark: After all, no bird has winglets. Not ...
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1answer
36 views

Components of the concept of Developmental Noise?

Developmental noise is a concept that correspond to the amount of possible phenotypic variance of a given genotype in a given environment. Intrinsic noise (aka Cellular noise) is a component of ...
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2answers
129 views

How does Natural Selection shape Genetic Variation?

Background Importance of the additive genetic variance As stated here, the fundamental theorem of Natural Selection (NS) by Fisher says: The rate of increase in the mean fitness of any organism ...
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1answer
91 views

What does “Mutational Variance” mean?

Background The concept of mutational variance can be found in many articles including this one for example. The mutational variance of a trait number $i$ can be found in the M-matrix in position ...
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7answers
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Is there a biological mechanism for evolution encoded into our DNA?

Throughout high school, I remember learning about Darwin's theory of evolution as if it were near-fact. But something always seemed wrong about the ideas presented. Survival of the fittest Random ...
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3answers
141 views

Why has grey hair evolved?

A vast majority of humans get at least some grey hair as they age. As far as I know this applies to both genders and all races. Presumably this means that at least some grey haired humans have ...
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3answers
380 views

What exactly does adaptive mean?

This is a quote from Dey et al 2014: Hatching asynchrony is thought to be adaptive because... What exactly does adaptive mean here? Does it mean hatching asynchrony has fitness benefits? Or does ...
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3answers
100 views

How did the horned lizard evolve?

It's a lizard that has the ability to burst blood vessels in it's eyes and shoot blood as self defense. How can this behavior be explained evolutionary? Wouldn't it mean that there had to be some ...
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5answers
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Why are there species instead of a continuum of various animals?

As I understand it, various animal traits have to evolve gradually, but what happens to the species that are "neither here nor there"? To put it differently, if a species evolved from another, it did ...
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217 views

Where are the evolutionary “inbetweeners”? [closed]

The problem I've always had with evolution is the actual lack of variation between animals. More specifically, the lack of observable gradual change between species. Take for example the hammerhead ...
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57 views

Intuitive explanation for Kin- and Group- selection

It is known from theoretician in the field of kin selection that kin selection (inclusive fitness theory) and group selection are actually two sides of the same coin. In other words, these two ...
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28 views

coevolution by physical interaction between RNA sequences [closed]

There are several items that relate to the concerted evolution between pairs of sequences (especially structural) rRNA as a consequence of physical interaction in tertiary, or even quaternary ...
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24 views

detection of primary origin (natural selection or genetic drift) on alterations in sequences [closed]

I recently had a question about how to distinguish the origin of variations in the sequences of rRNA as to whether alterations are generated by genetic drift or natural selection. For me it has not ...
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1answer
87 views

What is the outcome of a human population starting with only 2 individuals? [closed]

Starting with a human population N = 2, is there any way the genetic variability seen today could have come about? I don't know that much about meiosis, but isn't there a very limited number of ...
3
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1answer
172 views

Soft and Hard selection

Seems to me that these two sources (M. Whitlock, B. Wallace) use different definitions of soft and hard selection. M. Whitlock: Soft selection occurs when the relative fitness of an individual is ...
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2answers
146 views

On evolution statistics [closed]

This basic evolution theory question has been haunting me since childhood and I'm kind of embarrassed that I can't explain it yet: Consider a butterfly. It's wings have evolved to look like the eyes ...
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$F_{ST}$ and the genetic variance in metapopulations

From this video (21'15''), the speaker gives the following formulae in order to calculate the between and among populations genetic variance from the $F_{ST}$: $$V_{Among Pop} = 2 F_{ST}V_G$$ ...
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1answer
41 views

Distribution of fitness in wild populations

If I get out in the wild observe wild populations and measure the distribution of fitness $f(w)$ in a given population. What will I find out? Will I observe a Gaussian distribution, a Poisson ...
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1answer
48 views

What is a sex-biased gene?

How do you define a male-biased gene and a female-biased gene as they are found in the abstract of this article.
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1answer
62 views

Definition of Sexual Selection?

How do you define Sexual Selection (SS)? (One might want to subdivide SS into intra- and inter- SS to answer) Is SS clearly different from Natural Selection (NS)? Is SS nested within NS or are NS ...
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2answers
81 views

problem with natural selection [duplicate]

I fail to see how natural selection can build any kind of new functionality. New functionality in a design requires sacrificing a complex series of meanwhile useless steps before the new ...
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1answer
89 views

Two-fold cost of sex and r/K selection theory

This article cites a bunch of articles (I haven't been through them) that the effect of the two-fold cost of sex is "reduced" in stable environment or in K-selected environment. It says: [..] the ...
4
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1answer
171 views

Evolution and the levels of selection

Reading Okasha's "Evolution and the levels of selection" he talks about "the levels of selection problem." There is a bit of a problem with this opening chapter because, while he talks about why the ...
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4answers
177 views

Has it been enough time for evolution through simple natural selection?

Let first state that I understand natural selection. I am not asking if evolution happened. I see evolution as a fact, but I do not assume the current theory of natural selection as fact. I wonder if ...
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78 views

Is there an evolutionary explanation for depression?

Evolutionarily speaking, depression (both clinical depression and temporary sadness) is a curious phenomenon. Since being depressed is likely to increase the chance of a person with it to commit ...
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0answers
72 views

Effects of Genetic Drift on Linkage Disequilibrium

From what I understood of @Canadianer's answer here... Genetic drift randomly causes negative or positive linkage disequilibria, by changing allele frequencies through random sampling. Natural ...
2
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1answer
40 views

Definition of Linkage Desiquilibrium (LD)

According to wiki, linkage disequilibrium $D$ equals $$D = x_{11} - p_1\cdot q_1$$ where: $$ \begin{matrix} \text{Haplotype} & \text{Frequency}\\ A_1B_1 & x_{11}\\ ...
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26 views

Source of information on the evolution of aging/senescence

Do you know a good review (published peer-reviewed or an online course or whatever) that offers a good overview of all hypothesis explaining the various patterns linked with aging? I'd like this ...
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59 views

Effect of natural selection on phenotypic variance

Short background Theoretically speaking, natural selection causes a decrease in genetic variance and because the environmental variance should remain unchanged, natural selection causes a decrease of ...
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2answers
97 views

Can I force evolution in a group of cells by removing all the smaller cells?

I actually have algae growing in water in a container. I was thinking if it was possible to filter the water so that all the small cells will be filtered out and only the bigger ones will remain to ...
3
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2answers
92 views

Heterozygosity under genetic drift

The wright-Fisher model of genetic drift is: $$p_{ij} = \binom{2N}{j}\left(\frac{i}{2N}\right)^j \left(1- \frac{i}{2N}\right)^{2N-j} $$ ,where $\binom{2N}{j}$ is a binomial coefficient. From this ...