Why can plants handle being polyploid way better than animals, where it is almost always fatal? I found a 2004 paper while searching about this topic, but I'm wondering if there have been any recent discoveries and if scientists are still actively looking for a definitive answer.
78326
is the multiplication of number of chromosomal sets from 2n to 3n (triploidy), 4n (tetraploidy) and so on. It is quite common in plants, for example many crops like wheat or Brassica forms. It seems to be rarer in animals but still it is present among some amphibian species like Xenopus.  As I know in mammals polyploidy is lethal (I don't mean tissue - limited polyploidy). I understand that triploidy is harmful due to stronger influence of maternal or paternal epigenetic traits that cause abnormal development of placenta, but why there is no tetraploid mammals?
70799
I read that wherever there is polytomy there is an unresolved pattern of divergence. I don't understand why this is so.  When divergence takes place, is it necessary that there will be division into only 2 paths? Can't there be more than 2 paths with all the paths being equally related to each other (that is, no 2 paths being related more to each other than to a third path)?  In other words, does a fully-resolved phylogenetic tree have to be dichotomous?
82843
With practice one can create a bonsai; no complicated modification of the DNA in a high-end lab required. The bonsai will even beget bonsai fruit.   What I am curious about is - if such bonsai fruit is planted again, will it give rise to a normal, or a bonsai tree?
66208
I am interested in why many small animals such as ants can lift many times their own weight, yet we don't see any large animals capable of such a feat.  It has been suggested to me that this is due to physics, but I am not even sure what to search for. Could someone explain why indeed it is easy for smaller objects/lifeforms to support several times their own weight, but this is harder as objects/animals become larger?
65303
Background  The standard definition of species refers to the concept of . If two lineages are found to be reproductively isolated, then we consider these two lineages to belong to different species. My question concerns evolved reproductive isolation in Drosophila sp. following labs due to experimental evolution.  Question  Have we ever demonstrated that two Drosophila sp. lineages that could initially interbreed (in nature or in labs) evolved through artificial selection (and drift and mutations) in labs to finally not be able to interbreed anymore either due pre- or post- zygotic isolation (see )? Or, in other words, have we ever demonstrated that two drosophila lineages evolved to become different species (reproductive isolation definition) in labs experiments?  If not, have we ever observed some partial reproductive isolation such as inbreeding depression for example?    Note: This question is motivated by @LotusBiology that could not receive the answers she/he was waiting for because he/she failed to ask questions that are possibly answerable! So I wanted to ask this question that somehow addresses  question he/she asked (now on-hold)  For more information about the concept of species, please have a look at
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I found phylogenetic tree in wikipedia is lacks of accuracy. It actually confusing with versions. Some terms was not scientifically accurate with dna analysis anymore  So are there anyone know where is the most updated datasource on the internet?
12208
Why, from the natural selection point of view, do only two sexes exist for animals?
117575
Scientists have found mammoth blood, and are planning to   How does one go from having its blood to a full blown living mammoth? Is it possible?    Why does it matter if the blood is frozen or not? Suppose one found dinosaur blood, could one clone a dinsosaur (as in say 'Jurassic Park')?
82225
Could cancer be in itself a evolutionary process? Maybe in some way could it be a process of variation? Or would this idea be completely without support, if so, why?   I don't mean that each case would lead to evolution, but that within an entire group of organisms, it could lead to case of of individuals developing ways to resist what caused the cancer, maybe in cases of individuals beating the cancer or in cases of successive generations of off spring from individuals with cancer?   Could it be possible that in rare cases it could lead to the development of new organs or specialized cells?
18636
Does someone know why DNA is composed of four nucleobases? In particular, is there an explanation for the number? Why four and not two, or eight?
92733
I asked a question about  and learned good things about senescence. Now I would like to know about immortality in plants, if there is some kind of immortality in plants and how this occurs - how does it protect itself from senescence?
122273
I am working on 4 different plants. I have the (RNA-Seq) data from sequencing. I look for two events E1 and E2, say, at certain positions in their genome. Let's say E2 is the common one and E1 is a special event. The positions I look for are identical across all 4 (in the genome). And let's say I see that the observation I have for 1 particular position is:      P1   P2  P3  P4 E1   0   20   0   17 E2 100   80 100  120    Here, P1 through P4 refers to plants and E1 and E2 refers to the events. E2 is more common. So, my objective is to actually check if E1 occurs more often in one or more plants than in the others. If they occur at the same proportion in all, of course it is not interesting to me.  I have 2 questions: (I have already asked  before but didn't get an answer)     Will a fisher test be right for this problem?    I hypothesize (Null) that the proportion of E1 is not different in occurrence between the 4 plants. Now, I set out to find if the proportion I have here is by any means significantly different. I use R, fisher.test() and I get p-value=2.5e-10. So, I reject my Null hypothesis for this case because I find strong evidence against it.  Sometimes, I have an observation like this,        P1   P2  P3  P4 E1   0   20   0  17 E2   0   80   0 120    then fisher.test() gives me a p-value of 0.147. So, I don't reject the Null   hypothesis. However, from a biological point of view, I would consider this significant. However fisher test answers the question I originally asked. I guess the proportion 0/0 for P1 and P3 are not useful (or not used).  So, my question is: Is it possible to modify the test such that it is sensitive even if E1 and E2 are 0 in 1 or more plants for a particular observation?     Having thought a bit to frame this post, I guess, in that case I have to ask a different question.
104602
Recently on biology SE there was a question evolutionary biology which generated a lot of interest. Often these sorts of questions attract a lot of opinionated and flawed answers, and answers that don't actually (attempt) to answer the question. Unfortunately they generally get well upvoted because there are not enough people capable of finding the flaws or understanding the question properly*, and they are still interesting.   Essentially the question asks "Previously I thought that evolution was about improvement, but someone corrected me - it is not actually about improvement.  and a correct answer would show that, first of all, evolution is a process of change, and the reason we see so much improvement (adaptation) is because of selection, a mechanism of evolution. In other words, selection, not evolution, explains the frequency of improvement.  Many answers came (and went) that were wrong or long opinion pieces. Some have persisted though, and in fact there is an accepted answer with a score of 52 (54 up, 2 down). That answer doesn't, in my opinion**, answer the question. It explains that selection doesn't necessarily lead to increased complexity, which is another issue entirely. I think it has got a lot of upvotes because it is in an interesting post and generally well written, but it would answer the question "Does evolution always increase organismal complexity?"  Would it be correct to flag answers, which have been heavily upvoted and accepted, as not an answer? Even though it is well received, and may be interesting to read, it does not even attempt to answer the question.  I've read some posts on meta about how to deal with accepted answers () but it's a bit different with such highly upvoted answers and questions which may garner some opinion in the answers, and whether an answer does indeed answer the question is less clear cut, so I'm unsure what to do. I would really appreciate some guidance - I'm not comfortable leaving such answers on a subject I care about, evolution is subject to a lot of misconceptions in the public and such answers won't help in stopping that. I have tried downvoting and commenting on the post but with no success, my comment saying explaining why I think the answer does not answer the question is multiple upvoted.    * Understanding the true nature of the question requires a deep understanding of the subject because, in large parts, it is down to subtle differences in two processes.  ** Opinions formed by doing a PhD in evolutionary biology studying the process of adaptation
61856
Since binomials are required to be unique only within a kingdom, two species can share the same binomial name if they are in different kingdoms. I know of one instance of this, Orestias elegans: this name denotes  (kingdom Animalia) as well as  (kingdom Plantae).  Are there other instances where one binomial name validly refers to two (or more!) species?
100250
Given that , I wonder if every intelligent biological species is capable of producing beings that are Force-Sensitive?   Or are there some species characteristics that can make it 100% impossible for them ever to produce a Force-sensitive individual.  NOTE: Let's exclude - if they exist in EU - things like random new-species-creating mutations - e.g. the individual should be 100% the same species, able to interbreed.
45851
When I watch wilderness specials for more than a few minutes, I notice a familiar pattern: predators are depicted as being alerted by the scent of blood. Wounded animals seem to make the best prey and predators seem to have a heightened awareness for the smell of blood.   It would seem that it would then be a disadvantage to evolutionary survival for female organisms to menstruate. How do females of a species not attract predators to the signal of menstrual blood?   Do female organisms in the wild actually menstruate? If so, is there a difference in the composition of menses that does not alert predators? How would this not at the very least give predators an idea of the general vicinity of the female?  If wild animals excrete their menses, do they have ways in which they are able to mask the evidence of its release or are they somehow internalizing the tissue so that they are not released?  If female organisms in the wild do menstruate, then why is this not a survival disadvantage?
88019
Can someone tell me where can I find detailed text about mechanisms of evolution of dominance? Or, if it is possible, I would be grateful if someone will tell me about them here.