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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154 views

Is there any evolutionary advantage of selection of L-amino acid over D-amino acid?

After listening to a scientific talk, I had this question that why in the natural selection process, are the L-amino acids selected over the D- form. However, we still we produce D-amino acids; ...
6
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1answer
220 views

What percentage of the (additive or not) genetic variance is explained by the 'n'- most important loci?

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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0answers
57 views

What are the common methods to estimate additive genetic variance?

Additive genetic variance can be estimated in a number of ways, and is a key concept in evolutionary biology and quantitative genetics. What are the typical methods (experimental designs) used to ...
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1answer
575 views

Why are urban birds still scared of humans?

I understand that animals are naturally scared of humans because we basically slaughtered every living thing we found in our way for millennia. How long does it take for them to genetically 'forget' ...
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1answer
44 views

What is the evolutionary purpose of white spots in nails and how can they be characterised due to Leukonychia? [closed]

Suppose you haven't hit your nails so the white spots are due to Leukonychia. Are the discoloration i.e. the white spots due to lower porosity (less minerals absorbing) or some other factor? I ...
5
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2answers
83 views

What is Environmental Robustness? Is it different from plasticity?

Hansen (2006) in his review uses the concept of environmental robustness independently of the other concepts of robustness (at pages 139 and 140) without defining ...
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1answer
47 views

Would humans eventually evolve to fight off fatal diseases if we didn't treat/vaccinate for them? [duplicate]

I am definitely pro vaccination, and the question is a bit morbid because people would die, but assuming that we didn't treat or vaccinate people for fatal diseases such as Ebola or the black death, ...
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6answers
886 views

How is evolution possible in contemporary humans?

I would like to know if evolution is continuing to happen in modern humans, assuming things like existence of the nuclear family structure, fidelity to one partner, etc. It seems to me the answer ...
2
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1answer
64 views

Speciation of humans? [duplicate]

Since we homo sapiens (and all other species) are continuously evolving, are humans undergoing speciation based on our environment? OR has there been any difference across people that could say ...
4
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1answer
229 views

Body size, what are the evolutionary trade-offs?

Background Considering just the "Kingdom Animalia" branch of organisms. It is clear that bigger does not necessarily mean better - there is large variation in body size... From the 94 µm long ...
4
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2answers
129 views

What governs the size of animal bodies?

Million of years ago there lived dinosaurs up to 36 m high. About 10,000 years ago lived Machairodontinae -compared to cats today they were huge. About 400,000 years ago lived Mammuthus trogontherii: ...
6
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3answers
2k views

What evolutionary adaptations cause trees to grow tall?

I think there are some obvious costs for trees to grow tall. Carbon and other nutrients costs, maintenance cost, energy cost (for growing, to bring water (and nutrients) up to the higher leaves, ...
3
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1answer
91 views

Inbreeding depression and dominance

From this article, second paragraph of the second page A classic theoretical result is that the mean of a character controlled by a single locus i with two alleles Ai1 and Ai2 is only affected by ...
9
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1answer
184 views

Are there specific features of birds that cats/small predators are attracted to?

I've recently heard a podcast, in which a professor describes one of the theories as to why we like abstract art. In his talk, he mentions an experiment with seagull chicks, in which the seagull ...
3
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2answers
274 views

Why do we have to exhale (or inhale) in order to speak?

Every time we speak, sing, or make any other kind of advanced noise with our throats, we exhale, or to put it that way, blow air through our throats. Why is this required? After all, speakers do not ...
6
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1answer
77 views

Reformulation of Hamilton's rule

Who (and in which article) was the first to reformulate Hamilton's rule using the letters $B$ and $C$?. See below comments on this reformulation. Hamilton, in his 1964's article gave a mathematical ...
7
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2answers
170 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 ...
2
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1answer
259 views

Is sexual selection evolutionarily advantageous?

Our biology teacher says that peacocks will soon become extinct because of bigger and bigger (and harder and harder) tails. Why natural selection did not eliminate sexual selection?
4
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1answer
81 views

How was the resemblance between apes and humans explained in pre-Darwinian biology?

Humans and apes have somewhat obvious similarities, these must have been apparent to natural philosophers before the possibility of a common ancestry was first proposed in the mid-1800's. These ...
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0answers
48 views

General time reversible model of evolution and Felsenstein model

I would like to get suggestions for the books related to General time reversible model of evolution and Felsenstein model etc. Specifically the mathematical treatment of these topics and concepts ...
4
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1answer
80 views

Is eating cooked food an evolved behavior or rather an intelligent one, passed down via culture?

I was just eating a rather rare steak when I started wondering whether eating foods cooked was something I would instinctively want to do if the practice hadn't been taught to me. So, is cooking food ...
1
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1answer
90 views

Possibility of Human cloning

Technology has evolved so much as to clone animals. But, what about human cloning? Is it really possible to create humans in lab? Or is it that technology has not advanced to that level..? Why cant ...
4
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1answer
250 views

Do any birds beside the family Columbidae (or any reptile or mammal) feed their 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 ...
2
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1answer
49 views

What can myelination tell you about the evolution of sensory receptors?

I am reading Avi Chaudhuri's Fundamentals of Sensory Perception and wondering if the information given about the somatosensory system could tell us anything about the way it evolved. It seems (at ...
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1answer
39 views

What is different between the pigment of giraffes and the pigment of flowers?

I saw this video created by Derek Muller and he says there that it is very unusual to evolutionary develop the colour of the skin without the pigment. That sounds reasonable but if so, what nutrients ...
5
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4answers
227 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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2answers
188 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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1answer
117 views

Interpretation of graph from evolutionary biology

I am studying evolutionary biology, and been presented with this graph: I am having some difficulties understand its meaning. For a start, why is time measured as a fraction of the population size? ...
3
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1answer
376 views

Like other animals, why humans don't have species & breeds?

Like other animals, why don't humans have species & breeds ? Even my pet dog is one type of breed, but we (humans) lack breeds & species? What is the main reason?
4
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1answer
47 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 ...
5
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2answers
95 views

Linkage disequilibrium with multiple alleles and loci

Linkage disequilibrium $\left(D\right)$ for two bi-allelic loci is defined as: $$D=X_{11}X_{22} - X_{12}X_{21}$$ where $X_{11},\ X_{12},\ X_{21},\ X_{22}$ are the frequencies of the haplotypes ...
5
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3answers
220 views

Why are there no tree-like plants that grow in lakes?

Looking at aerial photos of boreal forests, with dense woods clear-cut by quiet lakes, I wondered why exactly are the woods so clear-cut at the edge of water? Why won't trees develop adaptations that ...
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1answer
32 views

Testing monophyly from per site log-likelihoods without optimising branch lengths

How can I obtain per site log-likelihoods for a topology against an alignment without optimising branch lengths? (which software can I use to do this) Per site log-likelihoods can be used for various ...
7
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2answers
766 views

Why do plants fruit?

This is a two-part question: What is the point of fruit if not to be eaten? It’s is my understanding that organisms will adapt to survive and thrive. I understand that being eaten can spread seeds, ...
8
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2answers
351 views

Why does sex last so long?

I wonder why (especially human) sex lasts longer than just a few seconds? My thought is that the shorter it takes a man to ejaculate, the lesser is the risk that he gets interrupted by a rival or a ...
6
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3answers
143 views

Are there any known mutual symbiotic relationships that has more than two agents?

We are all familiar with the examples of symbiotic relationships in nature consisting of two agents, like lichen or the co-evolvement between certain birds and flowering plants. Do we know of any ...
3
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1answer
187 views

Do wolves bury food like dogs?

Many breeds of domestic dogs seem to like burying food, presumably in preparation for leaner times. Assuming that dogs evolved from animals similar to the modern wolves through a mix of natural and ...
9
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2answers
935 views

Which sex has higher variance of reproductive rate in modern societies - male or females?

Who has a more varied reproduction rate in modern western societies - men or women? The average rate is the same of course, but I wonder which sex have higher variance - higher variance means that ...
4
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1answer
32 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
53 views

Comparative leg sizes

When I was a child, my father showed me the classic essay "On Being the Right Size", J. B. S. Haldane. It talks (among other things) about how large animals need stockier legs to support their ...
3
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1answer
49 views

Confusion regarding niches in evolution theory

This is the definition of a niche from Crash Course: An area of the environment that requires a special set of skills or traits to extract food and reproduce. Obviously, this version of the ...
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3answers
92 views

Why don't fish groom each other?

Fish are often plagued by external parasites, which are presumably difficult for them to remove. There are well known cases where large fish come to coral reefs and allow smaller fish to pick off ...
9
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1answer
121 views

What are the costs associated with carrying lots of genetic material

What are the costs (if any) associated with carrying lots of genetic material (Big genome size)? energy for copying? raw material for copying? space in the cell? Maintenance cost (matter and ...
4
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1answer
90 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 ...
6
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1answer
410 views

Why did humans lose their fur?

The little amount of body hair humans have don't seem to be of much use for keeping warm. Our Simian cousins on the other hand sport thick furs. At which point during the species evolution and why ...
3
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1answer
41 views

Why are the genomes of some trees so large?

For example, the current longest known genome belongs to a tree: http://motherboard.vice.com/read/the-largest-genome-ever-sequenced-belongs-to-a-tree I have heard that this could potentially be ...
4
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1answer
858 views

How do I calculate the change in allele frequency in a haploid population under selection?

From this book For simplicity, let us consider a haploid organism and assume that the frequencies of alleles $A_1$ and $A_2$ are given by $x$ and $y=1-x$, respectively. We also assume that the ...
6
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1answer
120 views

Hill-Roberston effects and effective population size

From this article, first page, middle of the second column: Even if harmful alleles do not become fixed, they can still reduce the efficacy of selection on neighbouring loci through a process ...
4
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2answers
388 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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1answer
42 views

Does sociality evolved before or after the ability of motility?

According to book Life Ascending: The Ten Great Inventions o Evolution. (Lane, N.;2010), Motility has indeed transformed life on earth in ways that are not immediately apparent, from the ...