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The evolutionary pressure on having the pituitary reside in the brain is arbitrary. Instead, its (partly) neural origin make it part of the brain, and therefore it is not parsimonious to have the pituitary evolve to a structure located farther from the brain. Why would it migrate when it doesn't have to? The neuroanatomy of the pituitary is schematically as ...


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I will just extend on my comment... Statistics: Correlation Let's just talk about statistics. You can see a correlation between two things only if there is variation for these two things. It therefore, make no sense to look at a single trait that has no variance and ask "is it genetically coded?". The only thing that makes sense is to understand what ...


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With all due respect to Dr. Wilson, this is just an anthropocentric, post hoc ergo propter hoc logical fallacy. Dr. Wilson looked around the world we live in, saw that most intelligent creatures navigate by sight and/or sound and concluded that those sense are a prerequisite for intelligence. I see absolutely no evidence to support this theory. First of ...


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You are asking explanations about a creationist argument. One could provide explanations about some hypothesis that you may found in a science paper but not explanations for a creationist argument just because, by definition, a creationist argument is not supported by any evidence and logical thoughts. However, you may want to link to a creationist website ...


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To fully comprehend the concept of wobble base-pairing we need to consider the nucleotide sequences of the anti-codons in the tRNAs that have to "read" the genetic code when the mRNA is being translated on the ribosome. The nucleotide in the anti-codon's wobble position is, for example, often inosine. Under the rules for wobble base-pairing an Inosine can ...


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There is at least one species of highly mobile animal that can photosynthesize, depending on your definition of "highly mobile": Sea Sheep? This Adorable Sea Slug Eats So Much Algae It Can Photosynthesize The catch is that this animal does not produce its own chloroplast.


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To answer your question, we must first ask the question What is defined as intelligence? A googling will tell you that most people believe intelligence to be something related to apes or even more conservatively to humans. But, I find this to be a bit unpragmatic. The closest level of abstraction I find towards defining intelligence is this wiki on Animal ...


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He may be referring to the fact that many nocturnal animals wait for the cover of darkness to be able to get their food safely or in order to cloak themselves to approach their prey better. However, this seems to be a matter of personal opinion. He wants you to think that we are smarter because we have to hide and hunt in broad daylight. I haven't been able ...


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They're not fast enough A hornet has a top speed of around 40 kph, while a rabbit is only a touch faster, a deer can hit 75 kph (all figures from Wikipedia). In order to act as hunting insects they need to match the speed of these large animals in large enough numbers to surround and overpower them but these animals could easily match their speed or outpace ...


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They do exist. Many such examples can be found. Such as the most terrifying one, being social groups formed by Spiders, Anelosimus eximius documented here. Colonies of upto 9000 individuals have been documented by the scientists in their report. Also let's not forget Piranhas, another group of social animals, which take down much larger prey due to their ...


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Unfortunately for you, such animals do exist (O'Donnell et al. 2005). This is a direct field observation of a swarm of army ants attacking and consuming a 60cm long earthworm, as well as consuming a 10cm long snake. From the linked article: We collected workers from two Cheliomyrmex andicola foraging raids. During raid 1 on 26 September 2003 at ...


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The difference in energy requirements of a motile species make photosynthesis an unsuitable form of primary energy generation for them. Since plants are sessile, their energy consumption rates are lower. Plants have approximate respiration:photosynthesis rates of 0.35-0.9, as can be seen in this table (click to enlarge): Once the energy consumption ...


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Why be mobile? To follow the sun? Plants are mobile. Their seeds are. We have plants living on other plants. Once they have a spot on the sun though moving does not necessarily improve your situation, being stationary and defending your territory though does. (Growing taller, deeper roots, wider crowns)


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I'll address fish here. It's hard to tell which way is up with many sea-dwelling invertebrates, e.g. sea cucumbers. Sea urchins often are oriented "sideways" if you count their mouths as "down". All animals normally orient themselves in the most advantageous manner dependent on their situation. Probably the most important determiners are field of vision and ...


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People can satisfy their sexual urges on their own (that is, without a sexual partner) through masturbating. They cannot satisfy their hunger on their own (that, without food). I suppose people could eat one food while looking at another kind of food pretending that the food they are eating is the one that they are watching, but where's the fun in that? ...


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we included a script to calculate this in supplemental material http://onlinelibrary.wiley.com/doi/10.1111/mec.13034/full ....single segregating site per locus or up to a maximum of four SNPs, as is expected for short-read genomic data (see attached R script for estimation).


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Looking at this 2001 review paper by Rieseberg: http://evolution.powernet.ru/library/Scienc9.pdf (especially Box 2), drift and inbreeding are suggested ways that chromosomal rearrangements can become fixed. These forces are strongest small, isolated populations, such as populations experiencing the founder effect. Another model discussed in that paper is ...


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I just found a research about possibility of organism with loop DNA (Mostly bacteria) could use there DNA as antenna to transmit and receive radio wave around 1kHz http://www.wired.com/2011/04/bacterial-radio/ But as other said. Communication mostly evolve from sensory organ. So the radio wave has too much noise and could not give useful information about ...


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Reiterating the above comments. Have a look at Tajima's D. It provides an estimate for the number of segregation sites for a population under a neutral mutation model. The general form of the estimation for a diploid population is $E[S]=4N\mu\sum_{i=0}^{n-1} \frac{1}{i}$. Here the mutation rate of is per-genome not per-site, so $\mu=L * 10^{-9}$ where $L$ ...


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@Remi.b I think we can do better than 1962. Let's fast-forward here to 2014, in the post-genomic era. I think this paper provides some data relevant to your query: Possible mechanisms for Chromothripsis .


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This is speculation on my part, but it could be a sort of hard-wired biodiversity conservation. And as others have noted, it's not restricted to humans. In fact, this "weakness" to cuteness seems to extend throughout the animal kingdom, especially in mammals. There are numerous examples in nature of one species - even a predator - caring for the young of ...


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Why so many molluscs exhibit sinistral winding? The estimates of the number of molluscs vary quite greatly between 50,000 and 200,000 species. Of those molluscs species, about 70'000 are Gasteropoda. Gasteropa is most diverse Mollusca phylum. The winding you describe is present in all Gasteropoda and is often called the torsion. So the answer to why there ...


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The fraction of polymorphic sites that exist in a population is dependent on the biology of the organism. For instance, you would expect to find different rates of polymorphism in related plants that have different breeding systems, e.g. in Silene [1]. Past bottlenecks are also expected to decrease polymorphisms [2]. So, the answer to your question would ...


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If you think about it, monarchs must have a pretty strong genetic component to migration since often they only make one round trip at most in a lifetime. But its not as simple as passing a map in the DNA. If a mountain springs up on the route, the 'common sense' of the butterflies are still operational and they will tend to find their way around it. ...


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Welcome to Biology.SE Answering your question fully will require to write a whole book. Evolutionary Biology is a big field and I would recommend that your take some time to get an introduction (slightly more advanced than what you received in school). I am suggesting you take advantage of this free online resource. I am briefly making comments and ...


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You have to be very careful when saying what evolved into what. In fact you can only say that e.g. ancestors of modern amphibians evolved from the ancestors of modern fish. Ad. 1 Have a look at this simplified picture of the evolutionary tree of life Ad. 2 Yes all living organism including plants, bacteria, fungi, and animals can be placed on one ...


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No and yes. What you perceive as domestication has a lot to do with intelligence or even social intelligence of animals. Common fish is too stupid (from our point of view), to have any social bond with humans. Mammals are usually much closer and have similar structure of intelligence and patterns of behaviour. That only if you consider domestication as ...


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Not all animals are equally predisposed for domestication. To be easily domesticated, animal should have: Flexible diet - and not compete with humans for food Reasonably fast growth rate Ability to be bred in captivity Pleasant disposition Temperament which makes it unlikely to panic Modifiable social hierarchy Wikipedia link above has plenty of ...


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The process of evolution is a change in a population over time through changes in the heritable variation, and visible as changes in traits affected by the heritable variation (such as that in the DNA). This implies that, if a trait evolves over time, some kind of change has occurred in the genetic composition of a population. Here follows a ...


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Your intuitions all seem correct. Coalescent simulation should be faster, because you don't track the entire population history over all t generations as you do in the forward simulation. Rather, as you work backwards in time you are tracking a smaller and small population. And with coalescent simulations it is probably very hard to incorporate the full ...



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