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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120 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 ...
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2answers
226 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 ...
3
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1answer
62 views

What is the most recent well-attested common ancestor of chimpanzees and humans?

Humans and chimpanzees are related and thus have a most recent common ancestor. Of course pinning down this precise point is essentially impossible, so I'm interested in close ancestors of this most ...
3
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1answer
179 views

Fecundity per woman in early humans

The average fecundity per woman varies a lot from country to country. I call average fecundity per woman the average number of born children per woman. In Homo sapiens, what was the average fecundity ...
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1answer
155 views
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4answers
789 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 ...
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1answer
140 views

Duplicity Vs. Singularity of Mammals Organs [closed]

Are there known evolutionary reasons why mammals contain 2 of some organs (such as lungs and kidneys) and only 1 of some (such as liver)?
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2answers
2k views

What is the evidence that australopithecines were bipedal?

Before the discovery of Australopithecus afarensis in the 1970s, most anthropologists believed that an increase in brain capacity had preceded bipedal locomotion. However, this reconstruction of the ...
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3answers
4k views

What if rB=C in hamilton's rule?

Hamilton's rule states that if rB>C then a gene giving altruistic behaviour will increase in frequency in the population. What would happen if rB=C? Will an individual perform the altruistic act?
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1answer
175 views

The origin of molecular machines

DNA holds genetic information and holds the key to the evolution of living organisms. Transcription and translation mechanisms enable living cells to process information encoded in DNA. To that end, ...
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1answer
92 views

Poisonous plants, animals, mushrooms: is this always a kind of defense?

I wonder whether developing deadly toxins in the organism's body is always or usually a defensive strategy rather than a by-product.
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146 views

The skin color of bonobos

Why is that bonobos skin color on the areas not covered by hair are dark throughout life unlike the chimpanzee?
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0answers
37 views

How much difference in genome is enough to prevent interbreeding? [closed]

I am not a biologist. I am a software developer interested in genetic algorithms therefore i am probably talking to biologists who also have a knowledge of genetic algorithms. I need to "breed" ...
13
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1answer
785 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 ...
5
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1answer
97 views

How does the body “know” how to metabolize foreign substances

As a freshman biochemistry major, I find myself befuddled by our body's ability to perform complex chemical reactions to break down foreign substances. I can see how we would evolve explicit pathways ...
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0answers
68 views

How important is the womb's environment?

- Background - Talking about one phenotypic trait, the total phenotypic variance $V_p$ is decomposed into genetic and environmental variance for this trait, represented by the symbols $V_G$ and $V_E$ ...
2
votes
1answer
917 views

Why were dinosaurs not as smart as we are?

According to http://en.wikipedia.org/wiki/Dinosaur, Dinosaurs were the dominant terrestrial vertebrates for 135 million years. They had a lot of time to evolve. My question is: why were dinosaurs not ...
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3answers
223 views

Evolutionary chronology - if any, which species have evolved in the last 100 years

I heared somewhere, I cannot remember where, that there has not been an evolution observed in our lifetime. In life science class, right at the start, we was doing the usual MRSGREN (how to tell if ...
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3answers
372 views

Are domesticated animals really “more intelligent,” or is that a myth/misunderstanding?

Often do I hear people speaking of how the domestic house cats are more friendly, less ferocious, less savage-like, and smarter and/or than their distinct but equivalent feline-species friends, like ...
3
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4answers
242 views

Why do some people find vegetables so repellent when evolutionarily they should find them an attractive and thus tasty food?

Why do certain people (especially kids) find vegetables so "repellent" when evolutionarily they should find them an attractive and thus tasty food? I ask this question because if Darwin's theory of ...
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2answers
254 views

Did Darwin ever reach the conclusion that selection will remove variation?

According to simple models of selection the genetic variance in a population should be reduced by selection. (Fisher's fundamental theorem states that the rate at which a population can evolve is ...
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3answers
268 views

Evolution: One big population vs. many small populations

Let's say I want to evolve a bacterium that is resistant to an antibiotic. I want to do this by growing initially clonal populations of bacteria in presence of this antibiotic for a long time. I have ...
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1answer
742 views

Deciduous trees in tropical rainforest

Some books says the dominant plant form in tropical rainforest biome is broad leaved evergreen trees. Other books say it is broad leaved evergreen trees and deciduous trees. What is the most accepted ...
11
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2answers
213 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; ...
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1answer
242 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
71 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
906 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
79 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
159 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
71 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, ...
2
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1answer
262 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
316 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 ...
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2answers
187 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: ...
3
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1answer
112 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 ...
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1answer
236 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 ...
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2answers
569 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
83 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 ...
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0answers
82 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
110 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 ...
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1answer
122 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 ...
5
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1answer
362 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
69 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
59 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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3answers
471 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
603 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
182 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? ...
4
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1answer
1k 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
48 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
162 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
536 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 ...